Injurious Wildlife Species; Listing Three Anaconda Species and One Python Species as Injurious Reptiles

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 16

RIN 1018-AV68

[Docket No. FWS-R9-FHC-2008-0015; FXFR13360900000-145-FF09F14000]

Injurious Wildlife Species; Listing Three Anaconda Species and One Python Species as Injurious Reptiles

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

The U.S. Fish and Wildlife Service (Service or we) is amending its regulations under the Lacey Act to add reticulated python (

Python reticulatus

), DeSchauensee's anaconda (

Eunectes deschauenseei

), green anaconda (

Eunectes murinus

), and Beni anaconda (

Eunectes beniensis

) to the list of injurious wildlife. By this action, the importation into the United States and interstate transportation between States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States of any live animal, gamete, viable egg, or hybrid of these four constrictor snakes is prohibited, except by permit for zoological, educational, medical, or scientific purposes (in accordance with permit conditions) or by Federal agencies without a permit solely for their own use. The best available information indicates that this action is necessary to protect the interests of human beings, agriculture, wildlife, and wildlife resources from the purposeful or accidental introduction and subsequent establishment of these large nonnative constrictor snake populations into ecosystems of the United States. We are also withdrawing our proposal to add the boa constrictor (

Boa constrictor

) to the list of injurious wildlife.

DATES:

This rule is effective on April 9, 2015.

ADDRESSES:

This final rule and the associated final economic analysis, regulatory flexibility analysis, and environmental assessment are available on the Internet at

http://www.regulations.gov

under Docket No. FWS-R9-FHC-2008-0015. Comments and materials received, as well as supporting documentation used in preparing this final rule, are available on the Internet at

http://www.regulations.gov

under Docket No. FWS-R9-FHC-2008-0015; they are also available for public inspection, by appointment, during normal business hours, at the South Florida Ecological Services Office, U.S. Fish and Wildlife Service, 1339 20th Street, Vero Beach, FL 32960-3559; telephone 772-562-3909 ext. 256; facsimile 772-562-4288.

FOR FURTHER INFORMATION CONTACT:

Bob Progulske, Everglades Program Supervisor, South Florida Ecological Services Office, U.S. Fish and Wildlife Service, 1339 20th Street, Vero Beach, FL 32960-3559; telephone 772-469-4299. If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

The U.S. Fish and Wildlife Service (Service) is amending its regulations under the Lacey Act to add the reticulated python, DeSchauensee's anaconda, green anaconda, and Beni anaconda to the list of injurious wildlife. The purpose of listing the reticulated python and the three anacondas as injurious wildlife is to prevent the accidental or intentional introduction and subsequent establishment of populations of these snakes in the wild in the United States.

Under the Lacey Act (Act) (18 U.S.C. 42, as amended), the Secretary of the Interior is authorized to list by regulation those wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, reptiles, and the offspring or eggs of any of the foregoing that are injurious to human beings, to the interests of agriculture, horticulture, or forestry, or to the wildlife or wildlife resources of the United States. We have determined that these four species of large constrictor snakes are injurious. This determination was based on an extensive risk and biological assessment by the U.S. Geological Survey (USGS; Reed and Rodda 2009) and on the criteria for injuriousness by the Service. USGS determined that these four species have a risk of invasiveness, and the Service found that the four species are injurious.

On March 12, 2010, we published a proposed rule in the

Federal Register

(75 FR 11808) to list

Python molurus

(which includes Burmese and Indian pythons), reticulated python (

Python reticulatus

), Northern African python (

Python sebae

), Southern African python (

Python natalensis

), boa constrictor (

Boa constrictor

), yellow anaconda (

Eunectes notaeus

), DeSchauensee's anaconda (

Eunectes deschauenseei

), green anaconda (

Eunectes murinus

), and Beni anaconda (

Eunectes beniensis

) as injurious wildlife under the Lacey Act.

On January 23, 2012, we published a final rule in the

Federal Register

(77 FR 3330) to list Burmese (and Indian) pythons, Northern African pythons, Southern African pythons, and yellow anacondas as injurious wildlife under the Lacey Act. The remaining five species (reticulated python, boa constrictor, green anaconda, DeSchauensee's anaconda, and Beni anaconda) were not listed at that time and remained under consideration for listing. With this final rule, we are listing four of those species (reticulated python, green anaconda, DeSchauensee's anaconda, and Beni anaconda) as injurious wildlife under the Lacey Act. We are, however, withdrawing our proposal to list the boa constrictor (

Boa constrictor

) as injurious; we are no longer considering adding that species to the list of injurious wildlife under the Lacey Act. Our rationale for this action is provided under Withdrawal of the Boa Constrictor from Consideration as an Injurious Species in this rule.

By listing the four species, the importation into the United States and transportation between States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States of any live animal, gamete, viable egg, or hybrid is prohibited, except by permit for zoological, education, medical, or scientific purposes (in accordance with permit conditions) or by Federal agencies without a permit solely for their own use.

The final economic analysis (2015) and environmental assessment (2015) considers four alternatives for the reticulated python, DeSchauensee's anaconda, green anaconda, Beni anaconda, and boa constrictor: Alternative 1 is no action; Alternative 2A would list all five species; Alternative 2B would list four species (not including the boa constrictor); Alternative 3 would list the three species known to be in trade in the United States (boa constrictor, green anaconda, and reticulated python); and Alternative 4 would list the boa constrictor—the only one of the five species with a high organism risk potential (Reed and Rodda 2009). We selected Alternative 2B.

Table ES-1 (from the 2015 final economic analysis) compares the economic output to the constrictor snake industry for listing under the alternatives. The costs for not listing are difficult to quantify, but include the expenditures associated with State and Federal activities that address constrictor snake impacts, amounting to at least $6 million from 2005 to 2014. Other costs for not listing include risk of harm (from predation, competition,

pathogens) to native species, including endangered and threatened species, and the potential for reduced tourism from decreased wildlife viewing opportunities.

Table ES-1—Annual Decrease in Secondary Impacts From Baseline Condition (Alternative 1)

[Dollars in millions]

Economic output

Jobs

Job income

Tax revenue

Alternative 2A

$26.5-$57.1

236-509

$9.5-$20.5

$3.6-$7.8

Alternative 2B

$5.3-$11.4

49-105

$1.9-$4.1

$0.7-$1.6

Alternative 3

$26.5-$57.1

236-509

$9.5-$20.5

$3.6-$7.8

Alternative 4

$21.1-$45.4

188-405

$7.7-$16.5

$2.9-$6.2

Previous Federal Actions

On June 23, 2006, the Service received a petition from the South Florida Water Management District (District) requesting that Burmese pythons be considered for inclusion in the injurious wildlife regulations under the Lacey Act (18 U.S.C. 42, as amended; the Act). The District was concerned about the number of Burmese pythons (

Python molurus bivittatus

) found in Florida, particularly in Everglades National Park and on the District's widespread property in South Florida.

The Service published a notice of inquiry in the

Federal Register

(73 FR 5784; January 31, 2008) soliciting available biological, economic, and other information and data on the

Python, Boa,

and

Eunectes

genera for possible addition to the list of injurious wildlife under the Act and provided a 90-day public comment period. The Service received 1,528 comments during the public comment period that closed April 30, 2008. We reviewed all comments received for substantive issues and information regarding the injurious nature of species in the

Python, Boa,

and

Eunectes

genera. Of the 1,528 comments, 115 provided economic, ecological, and other data responsive to the 10 specific questions in the notice of inquiry. Most individuals submitting comments responded to the notice of inquiry as though it was a proposed rule to list constrictor snakes in the

Python, Boa,

and

Eunectes

genera as injurious under the Act. As a result, most comments expressed either opposition or support for listing the large constrictor snakes species and did not provide substantive information. We considered all of the information provided, focusing primarily on the 115 applicable comments in the preparation of the draft environmental assessment, draft economic analysis, and the proposed rule.

On March 12, 2010, we published a proposed rule in the

Federal Register

(75 FR 11808) to list Burmese and Indian pythons, reticulated python, Northern African python, Southern African python, boa constrictor, yellow anaconda, DeSchauensee's anaconda, green anaconda, and Beni anaconda as injurious wildlife under the Act. The proposed rule established a 60-day comment period ending on May 11, 2010, and announced the availability of the draft economic analysis and the draft environmental assessment of the proposed rule. At the request of the public, we reopened the comment period for an additional 30 days ending on August 2, 2010 (75 FR 38069; July 1, 2010).

On January 23, 2012, we published a final rule in the

Federal Register

(77 FR 3330) to list Burmese and Indian pythons, Northern African python, Southern African python, and yellow anaconda as injurious wildlife under the Act. The remaining five species (reticulated python, boa constrictor, green anaconda, DeSchauensee's anaconda, and Beni anaconda) were not listed at the time and remained under consideration for listing. With this final rule, we are listing four of those species (reticulated python, green anaconda, DeSchauensee's anaconda, and Beni anaconda). We are also withdrawing our proposal to list the boa constrictor as injurious; we are no longer considering adding that species to the list of injurious wildlife under the Act. Our rationale for this action is provided under Withdrawal of the Boa Constrictor from Consideration as an Injurious Species in this rule.

On June 24, 2014, we reopened the comment period on the 2010 proposed rule for an additional 30 days (79 FR 35719). This comment period was restricted to the five remaining proposed species: The reticulated python, DeSchauensee's anaconda, green anaconda, Beni anaconda, and boa constrictor.

For the injurious wildlife evaluation in this final rule, in addition to information used for the proposed rule, we considered: (1) Comments from the three public comment periods for the proposed rule, (2) comments from five peer reviewers, and (3) new information acquired by the Service by the end of the public comment periods (July 24, 2014). From this information, we determined that four more (hereafter, also may be collectively referred to as “the second four”) of the nine proposed species warrant listing as injurious at this time, bringing the total number of species of large constrictor snakes listed as injurious to eight with this final rule. We present a summary of the peer review comments and the public comments following the Lacey Act Evaluation Criteria section for the second four of the nine proposed species. The explanations in the sections on biology and evaluation of the second four species will make many of the answers to the comments self-evident.

A major source of biological, management, and invasion risk information that we used for the proposed rule and this final rule was derived from the USGS's “Giant Constrictors: Biological and Management Profiles and an Establishment Risk Assessment for Nine Large Species of Pythons, Anacondas, and the Boa Constrictor” (hereafter referred to as “Reed and Rodda 2009).” This document was prepared at the request of the Service and the National Park Service; a link to the report can be found at the following Internet sites:

http://www.regulations.gov

under Docket No. FWS-R9-FHC-2008-0015 and

http://www.fort.usgs.gov/Products/Publications/pub_abstract.asp?PubID=22691.

The Service is completing actions on the proposed rule with publication of this final rule for the second four species (reticulated python and DeSchauensee's, green, and Beni anacondas). The proposal for one additional species (boa constrictor) is being withdrawn; we are no longer considering it for listing under the Act.

Background

Purpose of Listing as Injurious

The purpose of listing the reticulated python and the three anacondas as injurious wildlife is to prevent the accidental or intentional introduction and subsequent establishment of populations of these snakes in the wild in the United States.

Why the Species Were Selected for Consideration as Injurious Species

The Service has had the authority to list species as injurious under the Act since the 1940s. However, we have been criticized for not listing species before they became a problem (Fowler

et al.

2007). The Burmese python is one example of a species that may not have become so invasive in Florida if it had been listed before it had become established. Two of the largest snakes in the world (with maximum lengths exceeding 7 meters (m) (23 feet (ft)) are the reticulated python and green anaconda, and both are present in U.S. trade. The reticulated python and the green anaconda have been found in the wild in south Florida. With this final rule, we are attempting to prevent any further introduction and subsequent establishment of the reticulated python and green anaconda into vulnerable areas of the United States.

Furthermore, we have the authority under the Act to list certain species as injurious even if they are not currently in trade or known to exist in the United States. Thus, we can be proactive and not wait until a species is already established. As noted in the National Invasive Species Management Plan (National Invasive Species Council 2008), “prevention is the first line of defense” and “can be the most cost-effective approach because once a species becomes widespread, controlling it may require significant and sustained expenditures.” This is why we are listing two species (DeSchauensee's and Beni anacondas) that are not yet found in the United States but that have the requisite injurious traits.

None of these four species is native to the United States. The Service is striving to prevent the introduction and establishment of all four species into new areas of the United States, due to concerns about the injurious effects of all four species, consistent with 18 U.S.C. 42.

All four species were evaluated and found to be injurious because: There is a suitable climate match in parts of the United States to support them; they are likely to escape captivity; they are likely to prey on and compete with native species (including endangered and threatened species); preventing, eradicating, or reducing large populations would be difficult; and other factors that are explained in the sections Factors That Contribute to Injuriousness for Reticulated Python and for the other three species.

Withdrawal of the Boa Constrictor From Consideration as an Injurious Species

Under 18 U.S.C. 42(a), the Secretary of the Interior “may prescribe by regulation” species to be injurious and thus has discretion on whether to list species as injurious. The proposed rule published on March 12, 2010 (75 FR 11808), determined that the boa constrictor possesses the traits of injuriousness and no substantive information to the contrary has been provided in the public or peer review comments or otherwise obtained by the Service. Nonetheless, concurrent with this final rule, we are withdrawing the proposal to list the boa constrictor as an injurious species and hereby remove the species from further consideration. If we decide in the future to consider the boa constrictor for listing as injurious, we will prepare a new proposed rule for notice and comment in the

Federal Register

.

The Service recognizes the harm that the establishment of boa constrictors could pose to wildlife and wildlife resources. We also recognize that, because our regulatory authority is limited to prohibiting importation and interstate transport, we must rely on the States, Territories, and other governmental entities in the United States, including local jurisdictions (hereafter collectively referred to as the States) to regulate possession, release to the wild, sale, intrastate transport, and other activities that may need to be regulated to effectively manage the risk of a species introduction and spread for species that have already been imported into and are present in the United States.

The regulatory prohibitions of the Lacey Act (limited to importation and interstate transport) are less effective when a species is widely held in captivity in the United States in high numbers (both the number of animals and number of people owning the animals) and when significant domestic breeding of such animals is occurring and would likely continue for intrastate trade or export purposes. Domestic breeding, whether for intrastate trade or export, of widely-owned species increases the probability of escape, survival, and establishment of the listed species in the United States. Under these unique circumstances, the benefit of an injurious wildlife listing is likely to be limited without concurrent State regulatory action, particularly in areas of the country where the risk of establishment is the highest.

Thus, for the boa constrictor, we considered whether listing the species under the Lacey Act would be the most effective means of preventing the establishment and spread of populations in the wild. For this decision, the Service assessed information available on the number of boa constrictors already imported into the United States, the number of boa constrictors held in captivity in the United States, the variety of individuals and entities that own boa constrictors and their use of the species, how broadly in geographic terms the species is located in captivity within the United States, the amount of domestic breeding (for export, intrastate trade, and other purposes), the risk of escape and establishment of the species, if and where individual snakes have been recorded or populations have become established in the wild in the United States, and actions States have taken or could take to effectively manage the risk of snake introduction and establishment.

The number of boa constrictors that have been imported and that are currently held in captivity is a significantly larger portion of the current trade than for any of the other eight constrictor species that were proposed for listing. In fact, these numbers are likely higher for the boa constrictor than for all of the eight other species combined. Of the nine species that were included in the proposed rule, the boa constrictor represented 61.7 percent of the imports and domestically bred snakes from 2008 to 2010, whereas the next highest species was the Burmese python at 24.5 percent (Final Economic Analysis 2012). Of the five species not yet listed, the boa constrictor represents 79.2 percent of the imports and domestically bred snakes from 2011 to 2013, whereas the next highest species is the reticulated python at 18.9 percent. Large zoos and small roadside zoos across the country maintain boas for educational displays and live animal programs. Boa constrictors are sold in many pet stores, including large national chains, and are owned as pets by children and adults in all States that allow possession. Boas can grow to 13 feet in length and live for at least 20 years. The likelihood of pet boas being released or escaping is high, because boa constrictors are adept at escaping enclosures and they often outgrow their owner's ability or outlive their owner's interest to care for them.

Boa constrictors have been found on the loose in at least 46 States (HSUS 2014) and are known to be or assumed to be pets that escaped or were released. Boas are already well established in Florida and Puerto Rico. Therefore, the boa constrictor fits the circumstances where regulatory provisions of the Lacey Act are likely to be less effective.

Thus, of the nine large constrictor snakes evaluated by the Service, risk management measures by States are particularly needed for the boa constrictor, especially where the risk of establishment is high. Risk management measures include State regulations and other restrictions on activities with the species, as well as measures to detect and attempt to control any snakes that are found in the wild. For example, the State of Hawaii does not allow the importation or possession of any snakes, and most of the U.S. Territories have some restrictions on the importation of snakes. In comparison, the State of Florida has not listed the boa constrictor as a conditional reptile or placed other restrictions on this species. According to the State of Florida's regulations (FWC 2015), “[c]onditional nonnative species are considered to be dangerous to the ecology and/or the health and welfare of the people of Florida. These species are not allowed to be personally possessed, although exceptions are made by permit * * *.” Without any restrictions on possession, intrastate sale, or intrastate domestic production, the benefit of a Federal injurious wildlife listing for the boa constrictor is substantially less than for a species, such as the Burmese python, that is also held broadly in private ownership but is currently regulated through Florida's Conditional Reptile regulations. The lack of restrictions for boa constrictors in States such as Florida that are at great risk perpetuates an unregulated pathway for escape and possible establishment, and severely reduces the effectiveness of a Federal regulatory approach.

In 2010 (75 FR 11808, March 12, 2010; and 75 FR 38069, July 1, 2010) and again in 2014 (79 FR 35719; June 24, 2014), the Service sought and considered public comments submitted on the proposed rule to list the boa constrictor along with other species of large constrictor snakes. The Service received more than 85,000 public comments. Among the substantive comments we received were comments from the Association of Fish and Wildlife Agencies (AFWA) in 2010. Although AFWA did not submit additional comments in 2014, the Service has received no information indicating that AFWA has changed its position from that expressed in its 2010 comment letter.

AFWA represents North America's State, territorial, and provincial fish and wildlife agencies. In their comment letter, AFWA stated that they had solicited comments from their network of State nongame biologists and herpetologists, as well as members of their Amphibian and Reptile Subcommittee and Invasive Species Committee. AFWA stated its position that the Service should not finalize the rule for any of the large constrictor snakes. Specifically, AFWA stated, among other things, that a national rule may not be warranted; that it is the States' responsibility to manage species that occur within their borders, including minimizing impacts to native species; that States have the right to enact and enforce laws and regulations that are more stringent than Federal laws and regulations, as they see fit; that Federal regulations that create undue burdens on State fish and wildlife agencies should be avoided; and that listing the constrictor snakes as injurious might not achieve the desired result due to unintended consequences, such as people releasing the constrictors into the wild. As an alternative, AFWA promoted State action, such as Florida's “Reptiles of Concern” regulations, that, in partnership with stakeholders, AFWA believes would both discourage non-serious snake owners from purchasing new reptile pets as well as better regulate the industry. AFWA stated that Florida's regulations could serve as a model for development of industry-wide standards or enforceable best practices.

The Service recognizes that the States can enact their own, more stringent laws and that a Lacey Act listing does not preclude this, although States may have less ability to regulate importation into their States. However, AFWA's position is that it represents the collective interests of the States on this issue; that the Service could allow the States to take action, including regulatory action; that the Federal government could instead focus on financial support for risk analysis combined with early detection and rapid response programs; and that these actions could be more effective at preventing the establishment of constrictor snakes than Federal listing. Given the unique circumstances of the boa constrictor, we believe that, particularly for States where the risk of establishment is high, State action for the boa constrictor that effectively reduces the risk of escape and establishment, such as regulating possession, sale, intrastate transport, or breeding, could provide sufficient and even stronger protection than Federal listing as injurious under the Lacey Act. State laws that prohibit importation prevent the further spread of boa constrictors into States where they do not currently occur and reduce the chances of establishment by limiting additional importations in States where they do already occur. Laws such as Florida's regulations applicable to Conditional Reptiles (such as for Burmese pythons) restrict personal possession, while Hawaii prohibits both possession and importation. The Service agrees, as AFWA suggests, that State regulations, such as Florida's (for Burmese pythons) or Hawaii's, could serve as models for State laws, industry-wide standards, or enforceable best practices.

The Pet Industry Joint Advisory Council (PIJAC) also submitted comments on the proposed rule in both 2010 and 2014, although its 2014 comments were not related to the issues discussed here. PIJAC states that its mission is to promote responsible pet ownership and animal welfare, foster environmental stewardship, and ensure the availability of pets. PIJAC, through their comments, encouraged the Service to explore other alternatives to the proposed listing of the large constrictors. PIJAC stated that, in communications with the Department of the Interior, the Small Business Administration, and State agencies, they believe that opportunities exist for the Federal Government to work with the States and the industry to develop an alternative approach to large constrictor management and that they are prepared to work on this process. The Service has worked with PIJAC on several national campaigns to promote responsible ownership of nondomesticated animals and thus knows that such campaigns can be effective in promoting responsible use of wildlife that could be harmful if they escaped or are released to the wild.

For all of the reasons explained above, the Service has decided to withdraw its March 12, 2010 (75 FR 11808), proposal to list the boa constrictor in favor of a novel and experimental approach. The boa constrictor has already been imported in large numbers into the United States and is owned by hobbyists, commercial breeders, and pet owners in large numbers throughout the United States, except where prohibited by State law. AFWA, representing the State fish and wildlife agencies, has asserted that instead of listing the constrictor snakes as injurious, the Service could allow States to use their regulatory and management authorities to regulate activities with these species.

As the representative for these State fish and wildlife agencies and communicator of this position, presumably AFWA is prepared to work with its member States to do so. For the boa constrictor, a species that has already been imported into the United States in large numbers and is widely held in large numbers by a broad variety of owners for purposes that include breeding and sale, strong State laws are indeed more likely to be effective at preventing the escape or release and establishment of the species in the wild, given that prohibitions under the Lacey Act are limited to importation and interstate transport. This is especially true when combined with efforts by industry groups such as PIJAC, which has committed to work with the Service and the States on programs that would promote responsible holding and use of boa constrictors.

This action gives additional States, such as Florida, the opportunity to demonstrate the efficacy of coordinated, State-based measures to address the invasive nature of boa constrictors, including promulgating their own laws regarding the species. We are also providing the pet trade industry with the opportunity to act voluntarily within its own industry and in cooperation with the States, the Service, and others to address prevention and containment of the boa constrictor as an alternative to Federal Lacey Act restrictions. PIJAC and other industry groups can work with boa constrictor owners to develop practices to prevent escape or release into the environment and options for finding homes for unwanted animals as an alternative to release to the wild.

The Service recognizes that this is an untested approach and will monitor whether States and industry groups put in place effective measures to prevent the escape or release and establishment of boa constrictors. If States and industry groups in regions where the risk of boa constrictor survival and establishment in the wild is high fail to take appropriate actions, or if these State and industry-based measures prove ineffective, we may again evaluate whether listing the boa constrictor as injurious under the Act is appropriate.

Need for the Final Rule

Under the Lacey Act, the Secretary of the Interior is authorized to prescribe by regulation those wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, reptiles, and the offspring or eggs of any of the foregoing that are injurious to human beings, to the interests of agriculture, horticulture, or forestry, or to the wildlife or wildlife resources of the United States. We have determined that the reticulated python, DeSchauensee's anaconda, green anaconda, and Beni anaconda are injurious and should be listed under the Lacey Act.

Reticulated pythons have been found in the wild in Florida and Puerto Rico, as well as several other States. Several green anacondas have also been found in the wild in Florida. These species fit the circumstances where regulatory provisions of the Lacey Act are likely to be effective. The threat posed by the reticulated python and the three anacondas will be explained in detail below under Factors that Contribute to Injuriousness for Reticulated Python and each of the other species.

The USGS risk assessment used a method called “climate matching” to estimate those areas of the United States exhibiting climates similar to those experienced by the species in their respective native ranges (Reed and Rodda 2009). Considerable uncertainties exist about the native range limits of many of the giant constrictors, and a myriad of factors other than climate can influence whether a species could establish a population in a particular location. Nonetheless, this method represents the most accurate means to predict and anticipate where a nonnative species may be able to survive and establish populations within the United States (Bomford

et al.

2009). The authors used the same method to match the climate for all nine species in the proposed rule, because the method is not species-specific and can be used equally as well for pythons, boas, and anacondas.

Some interested parties, including other scientists such as Pyron

et al.

(2008), criticized Reed and Rodda's (2009) climate-matching method. In response, the authors published a clarification of how they used the model (Rodda

et al.

2011). This paper more clearly explained Reed and Rodda's (2009) method and compared that method to Pyron

et al.'

s (2008) method for analyzing potential invasiveness for the Burmese python. We mention a few of Rodda

et al.'

s (2011) findings here:

• Pyron

et al.

(2008) incorrectly rejected many sites that are suitable for Burmese python invasion because their use of an excessive number of parameters actually ended up acting as filters. Using too many filters means that too many sites that are truly at risk of python establishment get filtered out.

• Additionally, the authors eliminated four data points of blood pythons (

Python brongersmai

) that Pyron

et al.

(2008) used erroneously. This significantly changed the area that Burmese pythons could invade, even using the MaxEnt computer program as Pyron

et al.

(2008) used it.

• Information theory suggests 10 parameters as the appropriate number to use in a study like this; the Pyron

et al.

(2008) model, however, used 60. With this number, the parameters essentially become constraints, skewing the accuracy of the data to the point that the resulting model is not scientifically sound.

• The newer USGS paper highlights the statistical dangers inherent in indiscriminately searching for correlations among a large number of possible parameters.

• Factors other than climate may limit a species' native distribution, including the existence of predators, diseases, and other local factors (such as major terrain barriers), which may not be present when a species is released in a new country. Therefore, the areas at risk of invasion often span a climate range greater than that extracted mechanically from the native range boundaries, as was done by Pyron

et al.

(2008).

Rodda

et al.

(2011) does not change the previous USGS risk assessment, or the Service's interpretation of the USGS risk assessment, that Burmese pythons could find suitable climatic conditions in roughly a third of the United States. The paper also confirms that the climate matches for the four species in this final rule would not change from those described in the March 12, 2010 (75 FR 11808), proposed rule.

While we acknowledge that uncertainty exists, these tools also serve as a useful predictor to identify vulnerable ecosystems at risk from injurious wildlife prior to the species actually becoming established (Lodge

et al.

2006). Based on climate alone, many species of large constrictors are likely to be limited to the warmest areas of the United States, including parts of Florida, extreme south Texas, Hawaii, and insular territories. For a few species, larger areas of the southern United States appear to have suitable climatic conditions according to Reed and Rodda's (2009) climate-matching method.

The record cold temperatures in south Florida during January of 2010 produced the coldest 12-day period since at least 1940, according to the National Weather Service in Miami (NOAA 2010). A record low was set for 12 consecutive days with the temperature at or below 45 °F (Fahrenheit; 7.2 °C (Celsius)) in West Palm Beach and Naples. Other minimum temperatures for that period were broken in Moorehaven, tied in Fort

Lauderdale, and the coldest in Miami since 1940. Despite the record cold, we know that many pythons survived in Florida. For example, nearly 150 Burmese pythons were removed (captured or found dead) from the population in Everglades National Park and vicinity in 2011; more than 250 were removed in 2012, and more than 200 were removed in 2013 (NPS 2014). The largest Burmese python found in the wild in Florida was found in Everglades National Park in March 2012 (Krysko

et al.

2012). Large constrictors of several species continue to be present and to breed in south Florida. If thermoregulatory behavior or tolerance to cold is genetically based, we would expect large constrictor snake populations to persist, rebound, and possibly increase their genetic fitness and temperature tolerance as a result of natural selection pressures resulting from cold weather conditions such as those that occurred in south Florida in January 2010 (Dorcas

et al.

2011).

Two studies by scientists from several research institutions, including the University of Florida, studied the effects of the 2010 winter cold weather on Burmese pythons. These studies are relevant to the four species in this final rule because, like the Burmese python, the four species are poikilothermic (body temperature varies with surrounding temperature, also known as cold-blooded). Snakes typically maintain their body temperatures within thermal tolerance limits (ectothermy) through their behaviors (thermoregulation; Dorcas

et al.

2011), such as sunning in open areas in cool weather or seeking naturally insulated burrows in cold weather.

Thus, the reptiles seek locations (even small refugia) that can help them maintain a comfortable body temperature. In Mazzotti

et al.

(2010), the authors noted that all populations of large-bodied pythons and boa constrictors inhabiting areas with cool winters, including northern populations of Burmese pythons in their native range, appeared to rely on use of refugia (safe locations) to escape winter temperatures. Pythons and anacondas can seek such refugia as underground burrows, deep water in canals, or similar microhabitats to escape the cold temperatures. Those snakes that survived in Florida were apparently able to maintain body temperatures using microhabitat features of the landscape (Mazzotti

et al.

2010).

Dorcas

et al.

(2011) reported on the cold tolerance of adult Burmese pythons taken directly from the Everglades and placed in outdoor enclosures in South Carolina just prior to an unseasonably cold winter. Without time to suitably acclimate to a significantly colder climate, all of the snakes in this study died. The artificial refugia may not have been suitable compared to natural refugia (such as gopher tortoise burrows), which were not available in the study. Use of adults, as well as use of individuals that did not come from the colder parts of their native range, may have caused the snakes to not be adaptable to colder temperatures. Dorcas

et al.

(2012) state that their results suggest that Burmese pythons from the population currently established in Florida are capable of withstanding conditions substantially cooler that those typically experienced in southern Florida, but may not be able to survive severe winters in regions as temperate as central South Carolina. They noted that some snakes currently inhabiting Florida could survive typical winters in areas of the southeastern United States more temperate than the region currently inhabited by pythons. The authors also noted that, if thermoregulatory behavior is heritable, selection for appropriate thermoregulatory behavior will be strong as pythons expand their range northward through the Florida peninsula. Consequently, future generations of pythons and anacondas may be better equipped to invade temperate regions than those currently inhabiting southern Florida, particularly given the climate flexibility exhibited by the Burmese python in its native range (as analyzed through USGS' climate-matching predictions in the United States).

A study that used air temperatures to predict that Burmese pythons would not likely expand to or colonize more temperate areas of Florida and adjoining States (Jacobson

et al.

2012) did not offer any new data, other than summaries of ambient air temperature in Florida and South Carolina. Using the rationale in the study, based on air temperature, we could conclude that even native snakes could not survive in most of the United States, which is not the case. Snakes in the wild use a variety of physiological and behavioral mechanisms, not available to them in the captive studies, to regulate their body temperatures or escape excessive air temperatures.

Another paper that reviewed the effects of cold weather on Burmese pythons does not appear to introduce any new data that can be used to answer questions of temperature tolerances (Engeman

et al.

2014). Several conclusions drawn are seemingly based on untested hypotheses: (1) Measures of minimum temperature are superior to measures of mean temperature; (2) Indian and Burmese pythons are physiologically and behaviorally different in relation to thermal tolerance; and (3) the incorrect assumption of thermal critical minima structure of the range limits of the snakes that can behaviorally thermoregulate.

The only comparably large native reptile in the southeastern United States, the American alligator (

Alligator mississippiensis

), has been known to survive freezing air temperatures. A study at the Savannah River Ecology Laboratory in South Carolina found that adult alligators could survive freezing temperatures by adjusting their behavior. Adults could break the ice and breathe above the ice, whereas the juveniles could not break the ice and apparently drowned (Brandt and Mazzotti 1990).

The alligator study shows that even individual reptiles of the same species (juveniles compared to adults) may have different abilities to survive. Such reasoning could be applied to large constrictors. In Dorcas

et al.

(2011), 10 wild-captured male Burmese pythons from 2 to 3.5 m (6.5 to 11.5 ft) total length were released into outdoor enclosures in South Carolina. All eventually died ostensibly of cold stress, we surmise that perhaps individuals either larger or smaller could have survived.

Scientists continue to learn more about the adaptability of constrictor snakes. Whereas salinity had been suggested to be a limiting factor in the distribution of reptiles in coastal habitats, such as the Florida Keys (Dunson and Mazzotti 1989), a later study disproved that. Hart

et al.

(2012) found that hatchling Burmese pythons survived in a laboratory setting at full saltwater conditions for at least a month. This further supports our listing of the Burmese python and may be applicable to the species in this final rule because they are closely related.

Another study sought to explain why Burmese pythons became such successful invaders in Florida (Reed

et al.

2012). With all of the nonnative reptiles that have been introduced into the State, the Burmese python is the only exotic snake (other than the worm-sized Brahminy blindsnake (

Ramphotyphlops braminus

)) to have successfully colonized a large area (greater than 1,000 square kilometers (km

2

) (386 square miles (mi

2

))) of the United States. Reed

et al.

(2012) concluded that attributes related to body size and generalism (such as general habitat use and general prey) appeared to be particularly applicable to the

Burmese python's ability to spread and impact ecosystems in Florida. The attributes with the greatest scores were high reproductive potential, low vulnerability to predation, large adult body size, large offspring size, and high dietary breadth. All of these attributes are shared with the reticulated python and three anaconda species in this final rule, and all of these attributes contribute to the species' ability to become invasive.

The Service and Everglades National Park asked USGS to assess the risk of invasion of nine species of snakes to assist in the Service's determination of injuriousness. Of the nine large constrictor snakes assessed by Reed and Rodda (2009) (Burmese python (which Reed and Rodda refer to as Indian python), reticulated python, Northern African python, Southern African python, boa constrictor, yellow anaconda, DeSchauensee's anaconda, green anaconda, and Beni anaconda), five were shown to pose a high risk to the health of the ecosystem, including the Burmese python, Northern African python, Southern African python, yellow anaconda, and boa constrictor. The remaining four large constrictors—the reticulated python, green anaconda, Beni anaconda, and DeSchauensee's anaconda—were shown to pose a medium risk. None of the large constrictors that the USGS assessed was classified as low overall risk. A rating of low overall risk is considered as acceptable risk and the organism(s) of little concern (ANSTF 1996). See Lacey Act Evaluation Criteria, below, for an explanation of how USGS assessed risk.

There is a medium risk that the four large constrictors evaluated in this final rule, if they escape or are released into the wild, will establish populations within their respective thermal and precipitation limits due to common life-history traits that make them successful invaders. These traits include being habitat generalists (able to utilize a wide variety of habitats) that are tolerant of urbanization and capacity to hunt and eat a wide range of size-appropriate vertebrates (reptiles, mammals, birds, amphibians, and fish; Reed and Rodda 2009). These large constrictors are highly adaptable to new environments and opportunistic in expanding their geographic range. Furthermore, since they are a novel (new to the system) predator at the top of the food chain, they can threaten the stability of native ecosystems by altering the ecosystem's form, function, and structure.

These four species are cryptically marked and often dwell in trees or submerged in water with only their heads protruding, which makes them difficult to detect in the field, complicating efforts to identify the range of populations or deplete populations through visual searching and removal of individuals. No currently available tools appear adequate for eradication of an established population of giant snakes once they have spread over a large area. Therefore, preventing the introduction into the United States and dispersal to new areas of these invasive species is of critical importance to the health and welfare of native wildlife.

For the purposes of this rule, a hybrid is any progeny from any cross involving parents of one or more species from the four constrictor snakes evaluated in this rule. Such progeny are likely to possess the same biological characteristics of the parent species that, through our analysis, leads us to find that they are injurious to humans and to wildlife and wildlife resources of the United States. Anderson and Stebbins (1954) stated that hybrids may have caused the rapid evolution of plants and animals under domestication, and that, in the presence of new or greatly disturbed habitats, some hybrid derivates would have been at a selective advantage. Facon

et al.

(2005) stated that invasions may bring into contact related taxa that have been isolated for a long time. Facon

et al.

(2005) also stated that hybridization between two invasive taxa has been documented, and that in all these cases, hybrids outcompeted their parental taxa. Ellstrand and Schierenbeck (2000) concluded that dispersal of organisms and habitat disturbance by humans both act to accelerate the process of hybridization and increase the opportunities for hybrid lineages to take hold.

Furthermore, snakes in general have been found to harbor ticks (such as the nonnative African tortoise tick) that cause heartwater disease (from the bacterium

Cowdria ruminantium

). Heartwater disease, although harmless to its reptilian hosts, can be fatal to livestock and related wild hoofed mammals, such as white-tailed deer. According to the U.S. Department of Agriculture (USDA) (March 2000), “Heartwater disease is an acute, infectious disease of ruminants, including cattle, sheep, goats, white-tailed deer, and antelope. This disease has a 60 percent or greater mortality rate in livestock and a 90 percent or greater mortality rate in white-tailed deer.” The ticks have been found in Florida. Agricultural agencies are trying to stop the spread of the ticks as a way of stopping the deadly disease. This rule will help to stop the spread into and around the United States of the ticks and other disease vectors that may be carried by these four species of nonnative constrictor snakes.

Listing Process

The regulations contained in 50 CFR part 16 implement the Act. Under the terms of the Act, the Secretary of the Interior is authorized to prescribe by regulation those wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, reptiles, and the offspring or eggs of any of the foregoing that are injurious to human beings, to the interests of agriculture, horticulture, or forestry, or to the wildlife or wildlife resources of the United States. The lists of injurious wildlife species are found at 50 CFR 16.11-16.15.

In this final rule, we evaluated each of the four constrictor snake species individually and determined each to be injurious and appropriate for listing. Therefore, as of the effective date of the listing (see

DATES

, above), their importation into, or transportation between, the States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the United States by any means whatsoever is prohibited, except by permit for zoological, educational, medical, or scientific purposes (in accordance with permit regulations at 50 CFR 16.22), or by Federal agencies without a permit solely for their own use, upon filing a written declaration with the District Director of Customs and the U.S. Fish and Wildlife Service Inspector at the port of entry. This rule does not prohibit intrastate (within State boundaries) transport of the listed constrictor snake species. Any regulations pertaining to the transport or use of these species within a particular State will continue to be the responsibility of that State.

We used the Lacey Act Evaluation Criteria as a guide to evaluate whether a species does or does not qualify as injurious under the Act. The analysis developed using the criteria serves as a basis for the Service's regulatory decision regarding injurious wildlife species listings. A species does not have to be established, currently imported, or present in the wild in the United States for the Service to list it as injurious. The objective of such a listing is to prevent that species' importation and likely establishment in the wild, thereby preventing injurious effects consistent with 18 U.S.C. 42.

Introduction Pathways for Large Constrictor Snakes

For the four constrictor snakes analyzed in this final rule, the primary pathway for the entry into the United

States is, or would likely be, the commercial pet trade. In the last few decades, most introductions of large constrictor snakes have been associated with the international trade in reptiles as pets. This trade includes wild-caught snakes, captive-bred, or captive-hatched juveniles from areas within their native countries. In their native ranges, a species may be captured in the wild and directly exported to the United States or other destination country, or wild-caught snakes may be kept in the country of origin to breed for export of subsequent generations. The main ports of entry for constrictor snakes are Miami, Los Angeles, Dallas-Ft. Worth, Baltimore, Detroit, Chicago, San Francisco, and Houston. From there, many of the live snakes are transported to animal dealers, who then transport the snakes to pet retailers. Large constrictor snakes are also bred in the United States and sold within the country.

A typical pathway of a large constrictor snake includes a pet store. Often, a person will purchase a hatchling snake (0.55 m (22 inches (in)) at a pet store or reptile show for as little as $25. The hatchling grows rapidly, even when fed conservatively, so a strong escape-proof enclosure is necessary. All snakes are adept at escaping, and constrictors are especially powerful when it comes to breaking out of cages. In captivity, they are most frequently fed pre-killed mice, rats, rabbits, and chickens. A tub of fresh water is needed for the snake to drink from and soak in. As it outgrows its tub, the snake will need to soak in increasingly larger containers, such as a bathtub. Under captive conditions, pythons and anacondas will grow very fast. After 1 year, a python may be 2 m (7 ft) and after 5 years it could be 7.6 m (25 ft), depending on how often it is fed and other aspects of husbandry. A female reticulated python, for example, can grow to more than 8.7 m (28.5 ft) long, weigh 140 kilograms (kg) (308 pounds (1bs)) or more, live more than 25 years, and must be fed larger prey, such as rabbits. Although the reticulated python is longer, the anaconda is the heaviest snake, with a 4-m (13-ft) green anaconda having bulk comparable to a 7-m (23-ft) reticulated python.

Owning a giant snake is a difficult, long-term, and somewhat expensive responsibility. This is one reason that some snakes are released by their owners into the wild when they can no longer care for them. Other snakes may escape from inadequate enclosures, which is a common pathway for large constrictor snakes to enter the ecosystem (Fujisaki

et al.

2009). The trade in constrictor snakes is international as well as domestic. From 2004 to 2013, more than 1.2 million live constrictor snakes of 13 species (

Python

spp.,

Eunectes

spp., and

Boa

spp.) were imported into the United States (Final Economic Analysis 2015). Besides the species proposed for listing, these included ball python (

Python regius

), a blood python (

P. curtus

), another blood python (

P. brongersmai

), Borneo python (

P. breitensteini

), Timor python (

P. timoriensis

), and Angolan python (

P. anchietae

), none of which has been proposed for listing as injurious. From 2004 to 2013, approximately 26,591 large constrictor snakes of two species listed by this rule were imported into the United States (Final Economic Analysis 2015; two species in this rule were not imported).

Of all the constrictor snake species imported into the United States, the selection of nine constrictor snakes for evaluation as injurious wildlife in the March 12, 2010, proposed rule (75 FR 11808) was based on concern over the giant size of these particular snakes combined with their quantity in international trade or their potential for trade. The world's four largest species of snakes (Burmese python, Northern African python, reticulated python, and green anaconda) were selected, as well as similar and closely related species and the boa constrictor. These large constrictor snakes constitute an elevated risk of injuriousness in relation to those taxa with lower trade volumes; are massive, with maximum lengths exceeding 6 m (20 ft; except for boas up to 4 m (13 ft)); and have a high likelihood of establishment in various habitats of the United States. The DeSchauensee's and Beni anacondas exhibit many of the same biological characteristics associated with a risk of establishment and negative effects in the United States.

The strongest factor influencing the chances of these large constrictors establishing in the wild are the number of release events and the numbers of individuals released (Bomford

et al.

2009; 2005). A release event occurs when one or more individuals of a nonnative species is either intentionally or unintentionally let loose in the wild. With a sufficient number of either intentional or unintentional release events, these species will likely become established in ecosystems with suitable conditions for survival and reproduction. In most cases, for nonnative species to cause economic or ecological harm, they must first be transported out of their native range and released within a novel locality, establish a self-sustaining population in this new location, and expand their geographical range beyond the point of initial establishment. Releases of large numbers of individuals often enable the incipient (newly forming), nonnative population to withstand the inevitable decreases in survival or reproduction caused by the environment or demographic accidents.

The release of many individuals into one location essentially functions as a source pool of immigrants, thus sustaining an incipient population even if the initial release was of insufficient size (or badly timed) to facilitate long-term establishment. Natural disasters, such as Hurricane Andrew in 1992, may have provided a mechanism for the accidental release of snakes, especially in light of large numbers of juvenile pythons frequently held by breeders and importers prior to sale and distribution (Willson

et al.

2010).

Large or consistent releases of individuals into one location may enable the incipient population to overcome behavioral limitations or other problems associated with small population sizes. This is likely the case at Everglades National Park, where the core nonnative Burmese python population in Florida is now located.

Because all four snakes in this final rule share traits that foster intentional or unintentional release events, allowing unregulated importation and interstate transport of these nonnative snakes will increase the risk of these species becoming established through increased opportunities for release. The release of large constrictor snakes at different times and locations improves, in turn, the chance of their successful establishment.

As a first step in understanding the ecology of these snakes and their potential impact on the Everglades ecosystem, the National Park Service began tracking Burmese pythons using radio-telemetry in the fall of 2005. The radio-tagged pythons have since demonstrated that female pythons make few long-distance movements throughout the year, while males roam widely in search of females during the breeding season (December-April). These results indicate an ability to move long distances in search of prey and mates. Pythons also have a “homing” ability. After being released far from where they were captured, they returned long distances (up to 78 kilometers (km); 48 miles (mi)) in only a few months. These findings suggest that pythons searching for a suitable home range have the potential to colonize areas far from where they were released (Snow 2008; Harvey

et al.

2008). A related study further supported

that Burmese pythons released in Everglades National Park have navigational senses, which may contribute to the invasion dynamics of Burmese pythons and similar species (Pittman

et al.

2014). These characteristics of Burmese pythons are likely shared by reticulated pythons and may also be shared by the anaconda species analyzed in this rule.

A second factor that is strongly and consistently associated with a species becoming invasive is a history of the species successfully establishing elsewhere outside its native range. We have no documentation of reticulated pythons or the three anacondas being invasive elsewhere in the world. However, this lack of data could be the result of the lack or low volume of these species being imported into other countries that have similar climatic conditions as the species' native range.

A third factor strongly associated with establishment success is having a good climate or habitat match between where the species naturally occurs and where it is introduced. Exotic (nonnative) reptiles and amphibians have a greater chance of establishing if they are introduced to an area with a climate that closely matches that of their original range. Species that have a large range over several climatic zones are predicted to be strong future invaders. The suitability of a country's climate for the establishment of a species can be quantified on a broad scale by measuring the climate match between that country and the geographic range of a species. Climate matching sets the broad parameters for determining if an area is suitable for a nonnative large constrictor snake to establish.

These three factors have all been consistently demonstrated to increase the chances of establishment by all invasive vertebrate taxa, including the four large constrictor snakes in this final rule (Bomford 2008, 2009). However, as stated above, a species does not have to be established, currently imported, or present in the wild in the United States for the Service to determine that it is injurious. The objective of such a listing is to prevent that species' importation, release into the wild, survival, and likely establishment in the wild, thereby preventing injurious effects consistent with 18 U.S.C. 42.

Species Information

Reticulated Python (Python reticulatus)

Native Range

Although native range boundaries are disputed, reticulated pythons conservatively range across much of Southeast Asia (Reed and Rodda 2009). They are found from sea level up to more than 1,300 m (4,265 ft) and inhabit lowland primary and secondary tropical wet forests, tropical open dry forests, tropical wet montane forests, rocky scrublands, swamps, marshes, plantations and cultivated areas, and suburban and urban areas. Reticulated pythons occur primarily in areas with a wet tropical climate. Although they also occur in areas that are seasonally dry, reticulated pythons do not occur in areas that are continuously dry or very cold at any time (Reed and Rodda 2009).

Biology

Three scientific names are mainly associated with the reticulated python:

Python reticulatus, Broghammerus reticulatus,

and

Malayopython reticulatus.

Please see Reed and Rodda (2009) for a discussion of the taxonomy and nomenclature of the latter two names. Reynolds

et al.

(2014) considers the genus as

Malayopython,

which may have merit. Therefore, we are including this as another synonym, so that if the genus does change, it is clear to which species we are referring.

The reticulated python is most likely the world's longest snake. Adults can grow to a length of more than 8.7 m (28.5 ft) (Reed and Rodda 2009), with a report of one in the Philippines at 10 m (32.8 ft) (Headland and Greene 2011). The maximum reported weight is 150 kg (330 lb) (Reed and Rodda 2009). As with all snakes, pythons can grow throughout their lives (Reed and Rodda 2009).

Like all pythons, the reticulated python is oviparous (lays eggs). The clutch sizes range from 8 to 124, with typical clutches of 20 to 40 eggs. Recently, this species was documented to reproduce by parthenogenesis (egg develops without fertilization by a male) when an 11-year-old female laid a clutch of 61 eggs without a male present for more than 2 years (Booth

et al.

2014). The reticulated python's life history is fairly representative of large constrictors because juveniles are relatively small when they hatch, but nevertheless are independent from birth, grow rapidly, and mature in a few years. Hatchlings are at least 61 cm (2 ft) in total length (Reed and Rodda 2009). We have no data on life expectancy in the wild, but several captive specimens have lived for nearly 30 years (Reed and Rodda 2009).

Reticulated pythons are extremely capable predators. Like all of the large constrictors, they are cryptically colored. In general, constrictor snakes have especially strong musculature, which enables them to hold onto struggling live prey almost as large as themselves. The giant size of reticulated pythons makes them especially strong, and, combined with their streamlined shape, makes them remarkably adept at climbing, passing through dense brush, and even swimming.

Reticulated pythons are primarily silent hunters that lie in wait along pathways used by their prey and then ambush them; the pythons kill by wrapping their muscular bodies around their victims, squeezing tighter as the prey exhales until the victims suffocate. The methods of predation used by the reticulated python (whether sit-and-wait or actively hunting, or whether diurnal or nocturnal), as well as the other three species of large constrictor snakes in this final rule, work as well in their native ranges as in the United States. The reticulated python is an opportunistic predator capable of preying on a wide range of species, including chickens, rats, monitor lizards, civet cats, bats, an immature cow, various primates, deer, wild boars, goats, cats, dogs, ducks, rabbits, tree shrews, porcupines, frogs, fish, and many species of wild birds (Reed and Rodda 2009). Prey size is roughly correlated with the python's body size, with young or small pythons eating small prey and larger pythons eating larger prey.

Reticulated pythons frequently swim in waterways, where they hunt for aquatic prey. Waterways also facilitate the pythons' dispersal to new areas. Smaller pythons can also climb trees to prey on arboreal animals, avoid predators, and thermoregulate.

A host of internal and external parasites plague wild reticulated pythons (Auliya 2006). The pythons in general are hosts to various protozoans, nematodes, ticks, and lung arthropods (Reed and Rodda 2009). Captive reticulated pythons can carry ticks of agricultural significance (potential threat to domestic livestock) (Burridge

et al.

2000, 2006; Clark and Doten 1995). Several studies (Burridge

et al.

2000, Kenny

et al.

2004, Reeves

et al.

2006) have shown disease agents in the ticks that travel internationally on reptiles, which may serve in the introduction of disease agents that could impact the health of local wildlife, domestic animals, and humans (Corn

et al.

2011).

The reticulated python can be an aggressive and dangerous species. Reed and Rodda (2009) cite numerous sources of people being bitten, attacked, and even killed by reticulated pythons in their native range. However, the only occurrences of human fatalities in the United States from reticulated pythons were caused by captive specimens. Outside of the United States, such as in the Philippines, reticulated pythons have been reported to kill and even

consume humans in remote hunter-gatherer cultures (Headland and Greene 2011). In that study, 11 of 19 Filipinos died from attacks by reticulated pythons; no attacks were by captive snakes. Of reticulated pythons that attacked people in the Philippines, the longest was 10 m (32.8 ft) (Headland and Greene 2011).

DeSchauensee's Anaconda (Eunectes deschauenseei)

Native Range

DeSchauensee's anaconda is known from a small number of specimens and has a limited range in northeast South America. As currently understood, the “yellow anacondas” comprise two species with entirely disjunct distributions (Reed and Rodda 2009). The northern form, DeSchauensee's anaconda (

Eunectes deschauenseei

), is known from a small number of specimens and has a limited range in northeast South America. The southern form, the yellow anaconda (

Eunectes notaeus

) has a larger distribution in subtropical and temperate areas of South America, and has received more scientific attention. We published a final rule to list the yellow anaconda as injurious on January 23, 2012 (77 FR 3330).

The DeSchauensee's anaconda is largely confined to the Brazilian island of Marajó, nearby areas around the mouth of the Amazon River, and several drainages in French Guiana. Although not well studied, DeSchauensee's anaconda apparently prefers swampy habitats that may be seasonally flooded. DeSchauensee's anaconda is known from only a few localities in northeast South America, and its known climate range is accordingly very small. While the occupied range exhibits moderate variation in precipitation across the year, annual temperatures tend to range between 25 °C (77 °F) and 30 °C (86 °F). We do not know whether the species could tolerate greater climatic variation.

Biology

DeSchauensee's anaconda appears to be the smallest of the anacondas, although the small number of available specimens does not allow unequivocal determination of maximal body sizes. Dirksen and Henderson (2002) record a maximum total length of available specimens as 1.92 m (6.3 (ft)) in males and 3.0 m (9.8 (ft)) in females.

In captivity, a DeSchauensee's anaconda was reported to live for 17 years, 11 months (Snider and Bowler 1992). The DeSchauensee's anaconda is live-bearing. Clutch sizes of DeSchauensee's anacondas ranged from 3 to 27 (mean 10.6 ± 9.6) in a sample of five museum specimens (Pizzatto and Marques 2007), a range far greater than reported in some general works (for example, three to seven offspring; Walls 1998).

DeSchauensee's anaconda is reported to consume mammals, fish, and birds, and its overall diet is assumed to be similar to that of the yellow anaconda (Reed and Rodda 2009). DeSchauensee's anacondas frequently swim in waterways, where they hunt for aquatic prey. Anacondas appear to use rivers to disperse (McCartney-Melstad 2012). Smaller anacondas can also climb trees to prey on arboreal animals, avoid predators, and thermoregulate.

Green Anaconda (Eunectes murinus)

Native Range

The native range of green anaconda includes aquatic habitats in much of South America below 850 m (2,789 ft) elevation plus the insular population on Trinidad, encompassing the Amazon and Orinoco Basins; major Guianan rivers; the San Francisco, Parana, and Paraguay Rivers in Brazil; and extending south as far as the Tropic of Capricorn in northeast Paraguay. The range of green anaconda is largely defined by availability of aquatic habitats. Depending on location within the wide distribution of the species, these appear to include deep, shallow, turbid, and clear waters, and both lacustrine and riverine habitats (Reed and Rodda 2009).

Biology

Reed and Rodda (2009) describe the green anaconda as truly a giant snake, having a very stout body and fairly reliable records of lengths over 7 m (23 ft). The females typically outweigh the males. Very large anacondas are almost certainly the heaviest snakes in the world, ranging up to 200 kg (441 lb) (Bisplinghof and Bellosa 2007), even though reticulated pythons, for example, may attain greater lengths (Reed and Rodda 2009).

The green anaconda bears live young. The maximum recorded litter size is 82, removed from a Brazilian specimen, but the typical range is 28 to 42 young. Neonates (newly born young) are around 70 to 80 centimeters (cm) (27.5 to 31.5 inches (in)) long and receive no parental care. As with all the large constrictor snakes, hatchlings can fall prey to other animals. If they survive, they grow rapidly until they reach sexual maturity in their first few years (Reed and Rodda 2009). While reproduction is typically sexual, Reed and Rodda (2009) report that a female green anaconda that was kept in captivity for 26 years with no access to males gave birth to 23 females. This raises the possibility that green anacondas are facultatively parthenogenetic, and that, theoretically, a single female green anaconda could establish a population.

The green anaconda is considered a top predator in South American ecosystems. Small anacondas appear to primarily consume birds, and as they grow larger, they shift to eating larger mammals and reptiles. The regular inclusion of fish in the diet of all anacondas increases their dietary niche breadth in relation to the other large constrictors, which rarely consume fish. Green anacondas consume a wide variety of endotherms (so-called warm-blooded animals) and ectotherms from higher taxa, including such large prey as deer and crocodilians (alligators are a type of crocodilian). The regular inclusion of fish, turtles, and other aquatic organisms in their diet increases their range of prey even beyond that of reticulated or Burmese pythons. Vertebrate animals that regularly inhabit aquatic habitats are likely to be most commonly consumed by green anacondas (Reed and Rodda 2009). Green anacondas would have a ready food supply anywhere that the climate and habitat matched their native range. Since green anacondas are known to prey upon crocodilians, they could potentially prey on alligators, which are common in the southeastern United States.

Green anacondas frequently swim in waterways, where they hunt for aquatic prey. Anacondas appear to use rivers to disperse (McCartney-Melstad 2012). Smaller anacondas can also climb trees to prey on arboreal animals, avoid predators, and thermoregulate.

Beni Anaconda (Eunectes beniensis)

Native Range

The Beni anaconda is a recently described and poorly known anaconda closely related to the green anaconda (Reed and Rodda 2009). The native range of the Beni anaconda is the Itenez-Guapore River in Bolivia along the border with Brazil, as well as the Baures River drainage in Bolivia. The green and Beni anacondas are similar in size, and the range of the Beni anaconda is within the range of the green anaconda (Bolivia).

Biology

Eunectes beniensis

is a recently described species from northern Bolivia, previously considered to be contained within

E. murinus. Eunectes beniensis

was discovered in the Beni Province of Bolivia—thus the common name of Beni anaconda and another alias of Bolivian anaconda. To an experienced herpetologist,

E. beniensis

is easily recognizable by its brown to olive-brownish ground color in combination with five head stripes and fewer than 100 large, dark, solid dorsal blotches that always lack lighter centers. To a novice,

E. beniensis

and

E. murinus

are similar in appearance.

E. beniensis

is primarily aquatic and eats a wide variety of prey, including fish, birds, mammals, and other reptiles.

Beni anacondas frequently swim in waterways, where they hunt for aquatic prey. Anacondas appear to use rivers to disperse (McCartney-Melstad 2012). Smaller anacondas can also climb trees to prey on arboreal animals, avoid predators, and thermoregulate.

Presence of the Four Constrictor Snakes in the United States

Of the four constrictor snake species that we are listing as injurious in this final rule, two have been reported in the wild in the United States, but none have been confirmed as reproducing in the wild in the United States (see

Current Nonnative Occurrences,

below); two of the four have been imported commercially into the United States during the period 2004 to 2013 (Final Economic Analysis 2015). Species “reported in the wild” are ones that have been found in the wild but without proof to date that they have reproduced in the wild. The greatest opportunity for preventing a species from becoming injurious is to stop a species from entering the wild; the second greatest opportunity is before a species becomes established in the wild (reported but not reproducing); and the smallest opportunity is when a species has become established (reproducing in the wild).

Table 1—Four Species of Large Constrictor Snakes and Whether They Have Been Reported in the Wild in the United States, Are Known To Be Reproducing in the Wild in the United States, or Have Been Imported for Trade (2004 to 2013)

Species

Reported in the wild in U.S.?

Reproducing in the wild in U.S.?

Imported into U.S. for trade? *

Reticulated python

Yes

No

Yes.

DeSchauensee's anaconda

No

No

No.**

Green anaconda

Yes

No

Yes.

Beni anaconda

No

No

No.**

* Data from Law Enforcement Management Information System (LEMIS; USFWS 2014)

** It is possible that this species has been imported into the United States incorrectly identified as one of the other species listed by this rule or the January 23, 2012, final rule (77 FR 3330); however, none has been reported.

Lacey Act Evaluation Criteria

We use the criteria below to evaluate whether a species does or does not qualify as injurious under the Lacey Act, 18 U.S.C. 42. The analysis that is developed using these criteria serves as a general basis for the Service's decision regarding injuriousness (not just for the four snake species we are listing in this final rule). Biologists within the Service who are knowledgeable about a species being evaluated assess both the factors that contribute to and the factors that reduce the likelihood of injuriousness.

(1) Factors that contribute to being considered injurious:

• The likelihood of release or escape;

• Potential to survive, become established, and spread;

• Impacts on wildlife resources or ecosystems through hybridization and competition for food and habitats, habitat degradation and destruction, predation, and pathogen transfer;

• Impact to endangered and threatened species and their habitats;

• Impacts to human beings, forestry, horticulture, and agriculture; and

• Wildlife or habitat damages that may occur from control measures.

(2) Factors that reduce the likelihood of the species being considered as injurious:

• Ability to prevent escape and establishment;

• Potential to eradicate or manage established populations (for example, making organisms sterile);

• Ability to rehabilitate disturbed ecosystems;

• Ability to prevent or control the spread of pathogens or parasites; and

• Any potential ecological benefits to introduction.

To obtain some of the information for the above criteria, we referred to Reed and Rodda (2009). Reed and Rodda (2009) developed the Organism Risk Potential scores for each species using a widely utilized risk assessment procedure that was published by the Aquatic Nuisance Species Task Force (ANSTF), called “Generic nonindigenous aquatic organisms risk analysis review process (for estimating risk associated with the introduction of nonindigenous aquatic organisms and how to manage that risk)” (ANSTF 1996). The ANSTF was created under the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (16 U.S.C. 4701

et seq.

) to provide a way for government agencies to develop a national program to reduce the risk of unintentional introductions, ensure prompt detection and response, and control established species.

The ANSTF (1996) procedure incorporates four factors associated with probability of establishment and three factors associated with consequences of establishment, with the combination of these factors resulting in an overall Organism Risk Potential (ORP) for each species. For the four constrictor snakes in this final rule, the overall potential risk of establishment was medium.

Certainties were highly variable within each of the seven elements or factors of the risk assessment mentioned above, varying from very uncertain to very certain. In general, the highest certainties are associated with species unequivocally established in new ranges because of enhanced ecological information on these species from studies in both their native range and in Florida. The way in which these subscores are obtained and combined is set forth in an algorithm created by the ANSTF (Table 2).

Table 2—The Algorithm That the ANSTF (1996) Defined for Combining the Two Primary Subscores (Reed and Rodda 2009)

Probability of establishment

Consequences of establishment

Organism Risk Potential (ORP)

High

High

High.

Medium

High

High.

Low

High

Medium.

High

Medium

High.

Medium

Medium

Medium.

Low

Medium

Medium.

High

Low

Medium.

Medium

Low

Medium.

Low

Low

Low.

Similar algorithms are used for deriving the primary subscores from the secondary subscores. However, the scores are fundamentally qualitative, in the sense that there is no unequivocal threshold that is given in advance to determine when a given risk passes from being low to medium, and so forth. Therefore, we viewed the process as one of providing relative ranks for each species. Thus, a high ORP score indicates that such a species would likely entail greater consequences or greater probability of establishment than would a species whose ORP was medium or low (that is, high > medium > low). Medium-risk species include the four species being designated as injurious by this rulemaking: Reticulated python, DeSchauensee's anaconda, green anaconda, and Beni anaconda. Medium-risk species, if established in this country, would put portions of the U.S. mainland, Hawaii, and insular territories at risk and constitute a great potential ecological threat. As stated above, we use this information in our evaluation to determine if a species meets the criteria of being injurious, but it is not the only information we use. The following sections on “Factors That Contribute to Injuriousness * * *” and “Factors That Reduce or Remove Injuriousness * * *” explain how we arrived at our determinations of injuriousness for each species.

Factors That Contribute to Injuriousness for Reticulated Python

Current Nonnative Occurrences

In Florida, reticulated pythons have been observed or removed from Bradenton, Clearwater, Miami, Sebastian, and Vero Beach. For example, a 5.5-m (18-ft) reticulated python was struck by a person mowing grass along a canal in Vero Beach in 2007, and a reticulated python was removed along Roseland Road in Sebastian (B. Dangerfield, pers. comm. 2010). In the Commonwealth of Puerto Rico, reticulated pythons have been collected in the western region of the island (Aguadilla and Mayaguez), and the southern region of the island (Guayama), including a 5.5-m (18-ft) long specimen (J. Saliva, pers. comm. 2009).

Media accounts from 1980 to 2014 report that reticulated pythons have escaped captivity or were spotted in the wild in the following States: California, Florida, Illinois, Kansas, Maine, New Jersey, Ohio, Pennsylvania, Washington, and West Virginia (HSUS 2014). This illustrates that the potential for release or escape is not confined to Florida and Puerto Rico but could occur in many States. The States listed were merely the ones for which we have reports. Other occurrences may not have been reported or the species not identified. See

Introduction Pathways for Large Constrictor Snakes,

above, for the explanation of how release events are relevant to the potential establishment of reticulated pythons.

Potential Introduction and Spread

The likelihood that a reticulated python will be released or will escape from captivity is high as evidenced by a number of reports as discussed above in

Current Nonnative Occurrences

and because they possess the physical traits that contribute to release or enable escape. Relatively few private pet owners can maintain such a large species properly throughout its lifetime, leading to intentional release or escape. Once out of captivity, reticulated pythons are highly likely to survive in natural ecosystems (primarily extreme southern habitats) of the United States. Reticulated pythons have a somewhat tropical native distribution, so the area of the mainland United States showing a climate match is exclusively subtropical, and limited to southern Florida and extreme southern Texas. Low- and mid-elevation sites in the United States' tropical territories (Guam, Northern Mariana Islands, American Samoa, Virgin Islands, Puerto Rico) and Hawaii also appear to be climate-matched to the requirements of reticulated pythons. If they escape or are intentionally released, they are likely to survive and become established within their respective thermal and precipitation limits. Reticulated pythons were recently documented to be able to reproduce parthenogenetically, meaning that females do not need males to lay viable eggs (Booth

et al.

2014). Thus, even just one female python could potentially create a population. Reticulated pythons are highly likely to spread and become established in the wild due to common traits shared by all the large constrictors we are listing as injurious in this rule, including: Rapid growth to a large size with production of many offspring; ability to survive under a range of habitat types and conditions (habitat generalist); ability to adapt to live in urban and suburban areas; ability to disperse long distances; and ability to conceal themselves and ambush a wide variety of prey.

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Reticulated pythons are highly likely to prey on U.S. native species, including endangered and threatened species where present. Their natural diet includes mammals, birds, reptiles, and fish. An adverse effect of reticulated python on endangered and threatened species is likely to be moderate to high.

Native fauna have no experience defending against such a novel, giant predator as the reticulated python. As discussed above under

Biology,

the reticulated python can grow to a length greater than 8.7 m (28.5 ft) and the maximum reported weight is 150 kg (330 lb). This is longer than any native terrestrial predator (including bears) in the United States and its territories, and heavier than most native predators (including black bears and many alligators). In comparison with the reticulated python, the longest snake native to the United States is much smaller. The longest native snake is the indigo snake (

Drymarchon corais

), attaining a maximum length of about 2.5 m (8 ft) (Monroe and Monroe 1968). A subspecies of the indigo snake is the eastern indigo snake (

D. corais couperi

), which grows to the same length as

D. corais.

The eastern indigo snake inhabits Georgia and Florida, and is listed as federally threatened by the Service. The native, endangered Puerto Rican boa's (

Epicrates inornatus

) maximum size is approximately 2 m (6.5 ft) (U.S. Fish and Wildlife Service 1986).

Unlike prey species in the reticulated python's native range, none of our native species has evolved defenses to avoid predation by such a large snake. Thus, native wildlife in the United States where reticulated pythons exist would be very likely to fall prey to the pythons (or any of the other three constrictor snakes we are listing in this rule). At all life stages, reticulated pythons can and will compete for food with native species; in other words, baby pythons will eat small prey, and the size of their prey will increase as the pythons grow. Once reticulated pythons are introduced and established, they may outcompete native predators (such as the federally protected Florida panther, eastern indigo snake, native boas, and hawks), feeding on the same prey and thereby reducing the supply of prey for the native predators.

Reticulated pythons are generalist predators that consume a wide variety of mammal and bird species, as well as reptiles, amphibians, and occasionally fish. This constrictor can easily adapt to prey on novel wildlife (species that they are not familiar with), and they need no special adaptations to hunt, capture, and consume them.

The United States, particularly the Southeast, has a diverse faunal

community that is potentially vulnerable to predation by the reticulated python. Juveniles of these large constrictors will climb trees and rocks to remove prey from bird nests and capture perching or sleeping birds. The southernmost part of the United States has suitable climate and habitat for reticulated pythons. The greatest biological impact of an introduced predator, such as the reticulated python, is the additional stress placed on imperiled native species, which may preclude their recovery. Based on the food habits and habitat preferences of the reticulated python in its native range, the species is likely to invade the habitat, prey on, and further threaten many of the federally endangered or threatened fauna in climate-suitable areas of the United States (Reed and Rodda 2009).

Reticulated pythons are also likely to decrease the populations of numerous potential candidate animals for Federal protection by hunting and eating them. Candidate species are plants and animals for which the Service has sufficient information on their biological status and threats to propose them as endangered or threatened under the Endangered Species Act of 1973, as amended (16 U.S.C. 1531

et seq.

), but for which development of a proposed listing regulation is precluded by other higher priority listing activities.

The final environmental assessment for the four species in this final rule (Final Environmental Assessment 2015) includes lists of species that are federally or State endangered or threatened in some climate-suitable States and territories: Florida, Hawaii, Guam, Puerto Rico, and the Virgin Islands. Other States have federally or State endangered or threatened species that would be suitable prey for large, nonnative constrictor snakes, including the reticulated python. These lists include only the species of the sizes and types that would be expected to be directly affected by predation by reticulated pythons and the other large, nonnative constrictors. For example, plants and marine species are excluded. In Florida, 13 bird species, 15 mammals, and 2 reptiles that are federally endangered or threatened could be preyed upon by reticulated pythons or be outcompeted by them for prey. Hawaii has 34 bird species and 1 mammal that are federally endangered or threatened that would be at risk of predation. Puerto Rico has 9 bird species and 10 reptile species that are federally endangered or threatened that would be at risk of predation or competition for prey. The Virgin Islands has one bird species and three reptiles that are federally endangered or threatened that would be at risk of predation or competition for prey. Guam has seven bird species and two mammals that are federally endangered or threatened that would be at risk of predation.

According to the climate suitability maps (Reed and Rodda 2009), endangered and threatened species from parts of Florida, southern Texas, Hawaii, and Puerto Rico would be at risk from the establishment of reticulated pythons. In addition, Guam, the U.S. Virgin Islands, and other territories would have suitable habitat and climate to support reticulated pythons, and these also have federally endangered and threatened species that would be at risk if reticulated pythons became established.

Potential Impacts to Humans

Like all pythons, reticulated pythons are nonvenomous. The reticulated python can be an aggressive and dangerous species of giant constrictor to humans. Reed and Rodda (2009) cite numerous sources of people being bitten, attacked, and killed by reticulated pythons in their native range. Headland and Greene (2011) determined that 26 percent of a segment of hunter-gatherer Filipinos had been attacked by reticulated pythons, some fatally. The only human deaths in the United States from reticulated pythons that we are aware of were from captive snakes (in Indiana, Iowa, Kentucky, Louisiana, Nevada, Texas, and Virginia; HSUS 2014). An established population of reticulated pythons would be expected to create the greatest public safety risk of all large constrictor snakes evaluated.

Captive reticulated pythons can carry ticks of agricultural significance (potential threat to domestic livestock) in Florida (Burridge

et al.

2000, 2006; Clark and Doten 1995), and likely to livestock outside of Florida. African tick species that use pythons as hosts may be vectors of heartwater, and these ticks have been observed to transfer to other hosts, including other giant constrictors, other reptiles, and dogs. Because multiple python species are typically held captive in close proximately to each other in the commercial trade, such proximity provides tick transfer opportunities to occur prior to retail sales (Reed and Rodda 2009).

The introduction or establishment of reticulated pythons would likely have negative impacts on humans primarily from the loss of native wildlife biodiversity and as carriers of livestock diseases, as discussed above. These losses would affect the aesthetic, recreational, and economic values currently provided by native wildlife and healthy ecosystems. Educational values would also be diminished through the loss of biodiversity and ecosystem health.

Factors That Reduce or Remove Injuriousness for Reticulated Python

Control

Eradication, management, or control of the spread of reticulated python will be highly unlikely once the species is established. No effective tools are currently available to detect and remove large, nonnative constrictor populations. Traps with drift fences or barriers are the best option, but their use on a large scale is prohibitively expensive. Additionally, some areas cannot be effectively trapped due to the expanse of the area and type of terrain, the distribution of the target species, and the effects on any nontarget species (that is, trapping native wildlife). While the Department of the Interior, USDA Animal and Plant Health Inspection Service (APHIS), and State of Florida entities have conducted some research on control tools, no currently available tools are adequate for eradication of an established population of large, nonnative constrictor snakes, such as the reticulated python, once they have spread over a large area.

Efforts to eradicate large, nonnative constrictor snakes in Florida have intensified to keep the expansion to a minimum as species are reported in new locations across the State. Natural resource management agencies are expending scarce resources to devise methods to capture or otherwise control any large, nonnative constrictor snake species. These agencies recognize that control of large constrictor snakes (as major predators) on lands that they manage is necessary to prevent the likely adverse impacts to the ecosystems occupied by the invasive snakes.

The final economic analysis was prepared for the four constrictor snakes that are the subjects of this final rule (USFWS 2015) and provides the following information about the expenditures for research and eradication in Florida, primarily for Burmese pythons, which provides some indication of the efforts to date. Control methods used for Burmese pythons may also be applied to other large constrictor snakes. The Service spent more than $600,000 over a 3-year period (2007-2009) on python trap design, deployment, and education in the Florida Keys to prevent the potential extinction of the endangered Key Largo woodrat (

Neotoma floridana smalli

) at

Crocodile Lake National Wildlife Refuge. More recently, the Service and USGS have spent up to $20,000 over the 2012-2013 period on planning efforts to address constrictor snake infestations and expect to spend between $25,000 and $50,000 from 2014 to 2018 (U.S. Fish and Wildlife Service, Rebekah Gibble, personal communication 2014). The South Florida Water Management District spent $334,000 between 2005 and 2009, and anticipates spending an additional $156,600 on research, salaries, and vehicles in the next several years. An additional $300,000 will go for the assistance of USDA Wildlife Services (part of USDA Animal and Plant Health Inspection Service). The USDA Wildlife Research Center (Gainesville (FL) Field Station) spent $15,800 in 2008-2009 on salaries, travel, and supplies. The USGS, in conjunction with the University of Florida, has spent over $1.5 million on research, radio telemetry, and the development, testing, and implementation of constrictor snake traps. Miami-Dade County Parks and Recreation Department, Natural Areas Management and Department of Environmental Resources Management have spent $60,875 annually on constrictor snake issues. The National Park Service has spent an average of $380,000 annually from 2004 to 2014, on various programs related to constrictor snake issues in the Everglades National Park (National Park Service, Carol Mitchell, personal communication 2014). All these expenditures total $6.5 million from 2004 to 2014 (estimated for 2014), or roughly an average of $586,000 per year. Despite this investment, all of these efforts have failed to provide a method for eradicating large, nonnative constrictor snakes in Florida.

Kraus (2009) exhaustively reviewed the literature on invasive herpetofauna. While he found a few examples of local populations of amphibians that had been successfully eradicated, he found no such examples for reptiles. He also states that, “Should an invasive [nonnative] species be allowed to spread widely, it is usually impossible—or at best very expensive—to eradicate it.” The reticulated python is unlikely to be one of those species that could be eradicated. Witmer and Fuller (2011) also found no reports of eradications of introduced reptiles in the United States.

Eradication will almost certainly be unachievable for a species that is hard to detect and remove at low densities, which is the case with all of the four large constrictor snakes that are the subjects of this final rule. They are well-camouflaged and stealthy, and, therefore, nearly impossible to see in the wild. Most of the protective measures available to prevent the escape of reticulated pythons are currently (and expected to remain) cost-prohibitive and labor-intensive. Even with protective measures in place, the risks of accidental escape are not likely to be eliminated. Since effective measures to prevent the establishment or eradicate, manage, or control the spread of established populations of the reticulated python are not currently available, the ability to rehabilitate or recover ecosystems disturbed by the species is low.

Potential Ecological Benefits for Introduction

While the introduction of reticulated pythons could potentially provide a food source for some native carnivores, species native to the United States are unlikely to possess the hunting ability for such large, camouflaged snakes and would not likely turn to reticulated pythons as a food source. However, juvenile snakes could fall prey to native wildlife such as alligators, raccoons, coyotes, and birds of prey. In addition, a large constrictor snake could prey on other nonnative species such as green iguanas, feral hogs, and black rats. The risks to native wildlife greatly outweigh these unlikely benefits. There are no other potential ecological benefits from the introduction into the United States or establishment in the United States of reticulated pythons.

Conclusion

The reticulated python can grow to a length of more than 8.7 m (28.5 ft); this is longer than any native, terrestrial animal in the United States and at least as long as any snake species in the world. Native fauna have no experience defending against this type of novel, giant predator. Several captive reticulated pythons have lived for nearly 30 years. The reticulated python can be an aggressive and dangerous species to humans. An established population of reticulated pythons would be expected to create the greatest public safety risk from all large constrictor snakes evaluated. Reticulated pythons can carry ticks of agricultural significance (potential threat to domestic livestock).

Because reticulated pythons are likely to escape from captivity or be released into the wild if imported; are likely to survive, become established, and spread if they escape captivity or are released into areas of the United States that have suitable climate and habitat; are likely to prey on and compete with native species for food and habitat (including endangered and threatened species); are likely to be disease vectors for livestock or native wildlife; cannot be easily eradicated, prevented from establishing, or reduced from large populations or new locations; and are likely to disturb ecosystems beyond the point of recoverability, the Service finds the reticulated python to be injurious to humans, agricultural interests, and wildlife and wildlife resources of the United States.

Factors That Contribute to Injuriousness for DeSchauensee's Anaconda

Current Nonnative Occurrences

We do not know of any occurrences of the DeSchauensee's anaconda in the United States.

Potential Introduction and Spread

DeSchauensee's anacondas share similar traits with the other three species of constrictor snakes, although they are smaller. A smaller-sized constrictor may be more desirable to some potential pet owners who want a constrictor snake but do not want to handle the larger species, and thus DeSchauensee's anacondas may eventually be imported into the United States as an alternative species. Because DeSchauensee's anacondas possess the same traits as other large constrictor snakes, such as powerful musculature, streamlined body, and fast growth rate, this species is likely to escape or be released into the wild if imported into the United States. DeSchauensee's anacondas are highly likely to spread and become established in the wild due to common traits shared by many large constrictors, including: Rapid growth to a large size with production of many offspring; ability to survive under a range of habitat types and conditions (habitat generalist); ability to disperse long distances; and ability to conceal themselves and ambush prey.

Reed and Rodda's (2009) map identified no areas of the continental United States or Hawaii that appear to have precipitation and temperature profiles similar to those observed in the species' native range, although the southern margin of Puerto Rico and its out-islands (for example, Vieques and Culebra) appear suitable. However, we do not know whether the species' native distribution is limited by factors other than climate. Reed and Rodda (2009) extended the climate match globally, meaning they used the climate data from the native range and found that they matched other parts of the Amazon Basin and tropical areas of the world. This leads to the conclusion that climate

is not the limiting factor but instead could be biogeography, competition, or other factors. If the small, native range is attributable to ecological (for example, competition with green anacondas), or anthropogenic (for example, habitat loss) factors, then Reed and Rodda's (2009) qualitative estimate of the climatically suitable areas of the United States would represent an underprediction.

Potential Impacts to Native Species (Including Endangered and Threatened Species)

The DeSchauensee's anaconda would likely have a similar impact as the yellow anaconda, which we listed as injurious in 2012. DeSchauensee's anacondas eat mammals, fish, and birds in their native range and will prey on native species, including select endangered and threatened species if they become established in the United States. Anacondas employ both “ambush predation” and “wide-foraging” strategies (Reed and Rodda 2009). Endangered and threatened wildlife occupying the DeSchauensee's anaconda's preferred habitats would be at risk.

The DeSchauensee's anaconda is larger (reported to 3 m (9.8 ft)) than the largest snake native to the continental United States. See

Potential Impacts to Native Species (Including Endangered and Threatened Species)

for the reticulated python for comparison to native predators.

Please also see

Potential Impacts to Native Species (Including Endangered and Threatened Species)

under Factors that Contribute to Injuriousness for Reticulated Python for a description of the impacts that DeSchauensee's anacondas would have on native species. These impacts are applicable to DeSchauensee's anacondas by comparing their prey type with the suitable climate areas and the listed species found in those areas.

According to the climate suitability maps (Reed and Rodda 2009; Final Environmental Assessment 2015), endangered and threatened species from part of Puerto Rico would be at risk from the establishment of DeSchauensee's anacondas. In addition, the global climate match produced by Reed and Rodda (2009) showed a broader tropical range than that of the native range, and that other tropical areas of the world appear to be climatically similar. Because Guam, the U.S. Virgin Islands, and other U.S. territories are tropical, the climate may be suitable. Puerto Rico has 9 bird species and 10 reptile species that are federally endangered or threatened species that would be at risk if DeSchauensee's anacondas became established. Guam has seven bird species and two mammal species that are endangered or threatened that could be at risk of predation. The Virgin Islands has one bird species and three reptile species that are endangered or threatened that could be at risk of predation.

Potential Impacts to Humans

The introduction or establishment of DeSchauensee's anacondas would likely have negative impacts on humans primarily from the loss of native wildlife biodiversity, as discussed above in the discussion for the reticulated python. These losses would affect the aesthetic, recreational, and economic values currently provided by native wildlife and healthy ecosystems. Educational values would also be diminished through the loss of biodiversity and ecosystem health. Agricultural interests may be negatively affected by imported anacondas carrying ticks that transfer harmful pathogens to livestock.

Factors That Reduce or Remove Injuriousness for DeSchauensee's Anaconda

Control

Prevention, eradication, management, or control of the spread of DeSchauensee's anacondas will be highly unlikely. Please see the “

Control

” section for the reticulated python for reasons why DeSchauensee's anacondas would be difficult to control, all of which apply to this large constrictor.

Potential Ecological Benefits for Introduction

While the introduction of DeSchauensee's anacondas could potentially provide a food source for some native carnivores, species native to the United States are unlikely to possess the hunting ability for such large, camouflaged snakes and would not likely turn to DeSchauensee's anacondas as a food source. However, juvenile snakes could fall prey to native wildlife such as alligators, raccoons, coyotes, and birds of prey. In addition, a large constrictor snake could prey on other nonnative species such as green iguanas, feral hogs, and black rats. The risks to native wildlife greatly outweigh this unlikely benefit. There are no other potential ecological benefits from the introduction into the United States or establishment in the United States of DeSchauensee's anacondas.

Conclusion

DeSchauensee's anacondas are likely to establish and spread to suitable permanent surface-water areas because of their large size, high reproductive potential, early maturation, rapid growth, longevity, and generalist surprise-attack predation. DeSchauensee's anacondas are highly likely to survive in natural ecosystems of a small but vulnerable region of the United States, including the southern margin of Puerto Rico and its out-islands, U.S. Virgin Islands, Guam, and other U.S. islands.

Because DeSchauensee's anacondas are likely to escape captivity or be released into the wild if imported into the United States; are likely to survive, become established, and spread if they escape captivity or are released; are likely to prey on and compete with native species for food and habitat (including endangered and threatened species); cannot be easily eradicated, prevented from establishing, or reduced from large populations or new locations; and are likely to disturb ecosystems beyond the point of recoverability, the Service finds the DeSchauensee's anaconda to be injurious to humans and to the wildlife and wildlife resources of the United States.

Factors That Contribute to Injuriousness for Green Anaconda

Current Nonnative Occurrences

An individual green anaconda (approximately 2.5 m (8.2 ft) total length) was found dead on U.S. 41 in the vicinity of Fakahatchee Strand Preserve State Park in Florida in December 2004 (Reed and Rodda 2009). Two medium-sized adults and a juvenile green anaconda were observed but not collected in this general area. A 3.65-m (12-ft) green anaconda was removed from East Lake Fish Camp in northern Osceola County, Florida, on January 13, 2010. This was the first live green anaconda to be caught in the wild in Florida (Florida Fish and Wildlife Conservation Commission 2010).

Potential Introduction and Spread

Green anacondas have escaped captivity or been released into the wild in Florida. They are likely to escape or be released because they can grow in captivity to enormous sizes (which makes them exceedingly powerful) and they must be fed a diet that could be prohibitively expensive. Green anacondas are likely to survive in the appropriate natural ecosystems of the United States. Much of peninsular Florida (roughly south of Gainesville) and extreme south Texas exhibit

climatic conditions similar to those experienced by green anacondas in their large South American native range, but the rest of the continent appears to be too cool or arid. Lower elevations in Hawaii and all of Puerto Rico have apparently suitable climates. Within the climate-matched area, anacondas are likely to establish in sites containing surface water. The primarily nocturnal anaconda species tends to spend most of its life in or around water. Green anacondas are highly likely to spread and become established in the wild due to their propensity for rapid growth to a large size and high reproductive rate; are capable of surviving under a range of habitat types and conditions (habitat generalist); have behaviors that allow them to escape freezing temperatures; can live in urban and suburban areas; can disperse long distances; and are well-concealed ambush predators. There is evidence that green anacondas are facultatively parthenogenetic and could therefore reproduce even if a single female is released or escapes.

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Green anacondas will prey on native species, including endangered and threatened species, if they become established in the United States. They are primarily aquatic and eat a wide variety of prey, including fish, birds, mammals, and other reptiles. The size of the prey also varies, depending on the age of the snake, with baby anacondas able to eat small prey, and large anacondas able to eat larger prey, such as tapirs, peccaries, deer, sheep, and caimans (Reed and Rodda 2009).

The green anaconda is generally considered the heaviest snake in the world (reported to 200 kg (441 lb)), with lengths over 7 m (23 ft) (Reed and Rodda 2009), much larger than the largest snake native to the continental United States. See

Potential Impacts to Native Species (Including Endangered and Threatened Species)

for the reticulated python for comparison to native predators and anticipated effects on native wildlife from green anacondas. Moreover, the green anaconda is a novel predator against which native species would not have evolved defenses.

According to the climate suitability maps (Reed and Rodda 2009; Final Environmental Assessment 2015), endangered and threatened species from parts of Florida, Hawaii, and most of Puerto Rico would be at risk from the establishment of green anacondas. Florida has 13 bird species, 15 mammals, and 2 reptiles that are federally endangered or threatened that could be preyed upon by green anacondas or be outcompeted by them for prey. Hawaii has 34 bird species and 1 mammal that are endangered or threatened that would be at risk of predation. Puerto Rico has 9 bird species and 10 reptiles that are federally endangered or threatened that would be at risk if green anacondas became established. Because Guam, the U.S. Virgin Islands, and other U.S. territories are tropical, the climate there also may be suitable. Guam has seven bird species and two mammal species that are endangered or threatened that would be at risk of predation. The Virgin Islands has one bird species and three reptile species that are endangered or threatened that would be at risk of predation.

Potential Impacts to Humans

The introduction or establishment of green anacondas would likely have negative impacts on humans primarily from the loss of native wildlife biodiversity, as discussed above in the discussion for the reticulated python. These losses would affect the aesthetic, recreational, and economic values currently provided by native wildlife and healthy ecosystems. Educational values would also be diminished through the loss of biodiversity and ecosystem health. Agricultural interests may be negatively affected by imported anacondas carrying ticks that transfer harmful pathogens to livestock.

Factors That Reduce or Remove Injuriousness for Green Anaconda

Control

Prevention, eradication, management, or control of the spread of green anacondas once established in the United States will be highly unlikely. Please see the “

Control

” section for the reticulated python for reasons why green anacondas will be difficult to control, all of which apply to this large constrictor.

Potential Ecological Benefits for Introduction

While the introduction of green anacondas could potentially provide a food source for some native carnivores, species native to the United States are unlikely to possess the hunting ability for such large, camouflaged snakes and would not likely turn to green anacondas as a food source. However, juvenile snakes could fall prey to native wildlife such as alligators, raccoons, coyotes, and birds of prey. In addition, a large green anaconda could prey on other nonnative species, such as green iguanas, feral hogs, and black rats. The risks to native wildlife greatly outweigh these unlikely benefits. There are no other potential ecological benefits from the introduction into the United States or establishment in the United States of green anacondas.

Conclusion

The green anaconda is the world's heaviest snake. Large adults are heavier than almost all native, terrestrial predators in the United States, even many bears, and longer than all native wildlife. Native fauna have no experience defending themselves against this type of novel, giant predator. The range of the green anaconda is largely defined by the availability of aquatic habitats. These include deep and shallow, turbid and clear, and lacustrine and riverine systems. Most of these habitats are found in Florida, including the Everglades, which is suitable climate for the species, as well at Texas, Hawaii, and Puerto Rico. Green anacondas are top predators in South America, consuming birds, mammals, fish, and reptiles; prey size includes deer and crocodilians. This diet is even broader than the diet of Burmese and reticulated pythons. Evidence exists that female green anacondas may be facultatively parthenogenetic and could therefore reproduce even if a single female is released or escapes into the wild.

Because green anacondas are likely to escape or be released into the wild if imported into the United States (note that the green anaconda has already been found in the wild in Florida); are likely to survive, become established, and spread if they escape captivity or are released; are likely to prey on and compete with native species for food and habitat (including endangered and threatened species); cannot be easily eradicated, prevented from establishing, or reduced from large populations or new locations; and are likely to disturb ecosystems beyond the point of recoverability, the Service finds the green anaconda to be injurious to humans and to wildlife and wildlife resources of the United States.

Factors That Contribute to Injuriousness for Beni Anaconda

Current Nonnative Occurrences

We do not know of any occurrences of the Beni anaconda in the United States.

Potential Introduction and Spread

Beni anacondas are closely related to green anacondas. Because Beni anacondas share similar traits with

other constrictor snakes, individuals are likely to escape because of their large size, powerful musculature, and streamlined shape. Pet anacondas are also likely to be released into the wild, in part because of their growth to a large size (which pet owners may not able to deal with) and because of the difficulty in finding suitable food. Because Beni anacondas are difficult for a novice to distinguish from green anacondas, Beni anacondas may appear in the pet trade in place of green anacondas. Beni anacondas are highly likely to survive in the appropriate natural ecosystems of the United States.

The Beni anaconda is known from few specimens in a small part of Bolivia, and Reed and Rodda (2009) judged the number of available localities to be insufficient for an attempt to delineate its climate space or extrapolate this space to the United States. Beni anacondas are known from sites with low seasonality (mean monthly temperatures in a narrow range of approximately 22.5 to 27.5 °C (72 to 77 °F), and mean monthly precipitation about 5 to 30 cm (2 to 12 in). Whether the species' native distribution is limited by factors other than climate is unknown as well as whether the small native range is attributable to ecological (for example, competition with green anacondas), or anthropogenic (for example, habitat loss) factors. If the native distribution is not limited by climate, then Reed and Rodda's (2009) qualitative estimate of the climatically suitable areas of the United States would represent an underprediction. As a component of the risk assessment, the Beni anaconda's colonization potential is described by Reed and Rodda (2009) as capable of survival in small portions of the mainland or on the United States' tropical islands (Hawaii, Puerto Rico, American Samoa, Guam, Northern Mariana Islands, Virgin Islands).

The Beni anaconda is highly likely to spread and become established in the wild due to its rapid growth to a large size, early maturation and high reproductive potential, a sit-and-wait style of predation, ability to survive under a range of habitat types and conditions (habitat generalist), behavior that allows it to escape freezing temperatures, adaptability to living in urban and suburban areas, ability to disperse long distances, and cryptic concealment.

Potential Impacts to Native Species (Including Endangered and Threatened Species)

Beni anacondas will prey on native species, including endangered and threatened species if they become established in the United States. They are primarily aquatic and eat a wide variety of prey, including fish, birds, mammals, and other reptiles. The size of the prey also varies, depending on the age of the snake, with baby anacondas able to eat small prey, and large anacondas able to eat very large prey. Anacondas employ both “ambush predation” and “wide-foraging” strategies (Reed and Rodda 2009). Endangered and threatened wildlife occupying the Beni anaconda's preferred habitats would be at risk.

The Beni anaconda is similar in size to the green anaconda, which is generally considered the heaviest snake in the world (Reed and Rodda 2009), much larger than the largest snake native to the continental United States. See

Potential Impacts to Native Species (Including Endangered and Threatened Species)

for the reticulated python for comparison to native predators and anticipated effects on native wildlife from Beni anacondas. Moreover, the Beni anaconda is a novel predator against which native species would not have evolved defenses.

Florida has 13 bird species, 15 mammals, and 2 reptiles that are federally endangered or threatened that could be preyed upon by Beni anacondas or be outcompeted by them for prey; many of those protected species live in the warmest part of the State. Hawaii has 34 bird species, and 1 mammal that are endangered or threatened that would be at risk of predation. Puerto Rico has 9 bird species and 10 reptile species that are federally endangered or threatened species that would be at risk if Beni anacondas became established. Guam has seven bird species and two mammal species that are endangered or threatened that would be at risk of predation. The Virgin Islands has one bird species and three reptile species that are endangered or threatened that would be at risk of predation.

Potential Impacts to Humans

The introduction or establishment of Beni anacondas would likely have negative impacts on humans primarily from the loss of native wildlife biodiversity, as discussed above in the discussion for the reticulated python. These losses would affect the aesthetic, recreational, and economic values currently provided by native wildlife and healthy ecosystems. Educational values would also be diminished through the loss of biodiversity and ecosystem health. Agricultural interests may be negatively affected by imported anacondas carrying ticks that transfer harmful pathogens to livestock.

Factors That Reduce or Remove Injuriousness for Beni Anaconda

Control

Prevention, eradication, management, or control of the spread of Beni anacondas once established in the United States will be highly unlikely. Please see the “

Control”

section for the reticulated python for reasons why Beni anacondas would be difficult to control, all of which apply to this large constrictor.

Potential Ecological Benefits for Introduction

While the introduction of Beni anacondas could potentially provide a food source for some native carnivores, species native to the United States are unlikely to possess the hunting ability for such large, camouflaged snakes and would not likely turn to Beni anacondas as a food source. However, juvenile snakes could fall prey to native wildlife such as alligators, raccoons, coyotes, and birds of prey. In addition, Beni anacondas could prey on other nonnative species such as green iguanas, feral hogs, and black rats. The risks to native wildlife greatly outweigh these unlikely benefits. There are no other potential ecological benefits from the introduction into the United States or establishment in the United States of Beni anacondas.

Conclusion

Large Beni anaconda adults are heavier than almost all native, terrestrial predators in the United States, even many bears. Native fauna have no experience defending themselves against this type of novel, giant predator. The range of the Beni anaconda is largely defined by the availability of aquatic habitats. Beni anacondas are top predators in South America, consuming birds, mammals, fish, and reptiles; prey size includes deer and crocodilians. This diet is even broader than the diet of Burmese and reticulated pythons.

Because Beni anaconda specimens are likely to escape captivity or be released into the wild if the species is imported into the United States; are likely to survive, become established, and spread if they escape captivity or are released; are likely to prey on and compete with native species for food and habitat (including endangered and threatened species); cannot be easily eradicated, prevented from establishing, or reduced from large populations or new locations; and are likely to disturb ecosystems beyond the point of recoverability, the Service finds the Beni anaconda to be

injurious to humans and to wildlife and wildlife resources of the United States.

Summary of Injurious Evaluations

Based on the Service's evaluation of the criteria for injuriousness, substantive information we received during the public comment periods and from the peer reviewers, along with other information regarding the large constrictor snakes (in Florida, Puerto Rico, and elsewhere), the Service concludes that the four constrictor species should be added to the list of injurious reptiles under the Lacey Act.

Comments Received on the Proposed Rule

During the two public comment periods for the proposed rule for the nine species (75 FR 11808, March 12, 2010; and 75 FR 38069, July 1, 2010) and one comment period for the five species (79 FR 35719, June 24, 2014), we received more than 85,000 comments, including form letters, petitions, and postcards. We received comments from Federal agencies, State agencies, local governments, commercial and trade organizations, conservation organizations, nongovernmental organizations, and private citizens; all were in English with the exception of a few in Dutch, French, German, and Italian. The comments provided a range of views on the proposed listings as follows: (1) Unequivocal support for the listings with no additional information included; (2) unequivocal support for the listings with additional information provided; (3) equivocal support for the listings with or without additional information included; (4) unequivocal opposition to the listings with no additional information included; and (5) unequivocal opposition to the listings with additional information included.

To accurately review and incorporate the publicly provided comments in our final determination, we worked with researchers in the Qualitative Data Analysis Program at the University of Massachusetts Amherst and the University of Pittsburgh—developers of the

Public Comment Analysis Toolkit

(

PCAT

) and the successor DiscoverText analytical platform. The PCAT and DiscoverText enhanced our ability to review large numbers of comments, including large numbers of similar comments on our proposed listings, allowing us to identify similar comments as well as individual ideas, data, recommendations, or suggestions on the proposed listings. We are also responding to some comments that are out of the purview of this rule in a concerted effort to explain our rationale to the public.

Peer Review of the Proposed Rule

In accordance with peer review guidance of the Office of Management and Budget “Final Information Quality Bulletin for Peer Review,” released December 16, 2004, and Service guidance, we solicited expert opinion on information contained in the March 12, 2010, proposed rule (for nine species) from five knowledgeable individuals selected from specialists in the relevant taxonomic group and ecologists with scientific expertise that includes familiarity with alien herpetological introductions and invasions, predictive tools for risk assessment, and invasion biology. In 2010, we posted our peer review plan on the Service's Region 4 Web site (

http://www.fws.gov/southeast/informationquality

), explaining the peer review process and providing the public with an opportunity to comment on the peer review plan. No comments were received regarding the peer review plan. The Service solicited independent scientific reviewers who submitted individual comments in written form. We avoided using individuals who had already expressed strong support for or opposition to the petition and individuals who were likely to experience personal gain or loss (financial, prestige, etc.) as a result of the Service's decision. Department of the Interior employees were not used as peer reviewers.

We received responses from five peer reviewers. Two peer reviewers found that, in general, the proposed rule represented a comprehensive and up-to-date compilation of the best scientific information known about the nine constrictor snake species and that conclusions drawn from both published and unpublished sources were scientifically robust, and justified the proposed rule. Two peer reviewers expressed concern with the climate-matching methods and assumptions.

In addition, all peer reviewers stated that the background material on the biology, invasive potential, and potential tools for control of each snake species represented a solid compilation of available information. They further stated that the information as presented justified the conclusion that the snake species should be listed as injurious. All five peer reviewers concluded that the data and analyses we used in the proposed rule were appropriate and the conclusions we drew were logical and reasonable. Several peer reviewers provided additional insights to clarify points in the proposed rule, or references to recently published studies that update material in the rule.

Peer Review Comments

We reviewed all comments we received from peer reviewers for substantive issues and new information regarding the proposed rule. We consolidate the comments and responses into key issues in this section. We refer to them as PR (Peer Reviewer) 1 through 5. We revised the final rule to reflect peer reviewer comments, where appropriate, and the most current scientific information, including the results of the newer USGS climate match publication (Rodda

et al.

2011), plus a number of new peer-reviewed journal articles. We have taken our best effort to identify the limitations and uncertainties of the climate-matching models and their projections used in the March 12, 2010, proposed rule. We have also taken our best effort to correct any grammatical or biological errors and clarify certain ambiguous statements. Because some of the comments referred only to those constrictor snake species we listed on January 23, 2012 (77 FR 3330), we omit those comments from this final rule; we summarize and respond to them in the January 23, 2012, final rule to list the Burmese python and three other species.

Comment PR1:

In regard to the USGS publication “Giant Constrictors: Biological and Management Profiles and an Establishment Risk Assessment for Nine Large Species of Pythons, Anacondas, and the Boa Constrictor,” which includes management profiles discussing colonization potentials with climate-matching maps, very few details or data are presented that would allow an independent test of the model, predictions, or assumptions. At a minimum, the threshold values that were used in the climate space model should be explicitly stated for each species. This would allow reviewers to evaluate the data and the assumptions used in the construction of the model.

Response PR1:

This general critique is incorrect; all of the species-specific information used to assess risks is presented in the document mentioned. That this procedure cannot be reduced to mathematical certainty is the reason a risk assessment (rather than a calculation) was conducted. This specific critique is also incorrect. The requested threshold values are provided graphically for each of the species in Reed and Rodda (2009). For example, the

Python reticulatus

values are in Figure 5.3 (page 84) (heavy and dashed black lines), the

Eunectes murinus

and

Eunectes beniensis

values are in Figure 9.3 (page 224) (heavy black lines), and so forth.

For readers who want to duplicate the climate match results, the USGS has published a data series report with data used for modeling and the equations corresponding to these lines (

http://pubs.usgs.gov/ds/579/

) (Jarnevich

et al.

2011), but the graphical representations in Reed and Rodda (2009) provide the same information with the precision that is appropriate for the use of these values. Use of these values with greater precision would not be appropriate given the conceptual and scientific uncertainties that attend state-of-the-art implementation of climate matching.

Comment PR2:

The data used for the risk assessment seems fair. This reviewer, however, was not convinced that the assignment of low, medium, and high establishment and consequence scores was sufficiently objective or transparent. The process appears to involve high levels of uncertainty (pp. 253, 259: Reed and Rodda 2009). Though there is not really an alternative with the amount of data available, the approach would be more acceptable if it was transparent (what constitutes each level of certainty and how one decides on high, medium, or low for each contributing factor).

Response PR2:

The risk assessment process allows for analyzing, identifying, and estimating the dimension, characteristics, and type of risk. By applying analytical methods while acknowledging the assumptions and uncertainties involved, the process allows the assessors to utilize qualitative and quantitative data in a systematic and consistent fashion. The assessment strives for theoretical accuracy while remaining comprehensible and manageable, and the scientific and other data compiled for each snake species in the bio-profiles is organized and recorded in a formal and systematic manner. The assessment provides a reasonable estimation of the overall risk. The authors were careful to ensure that the process clearly explained the uncertainties inherent in the process and to avoid design and implementation of a process that reflected a predetermined result. Quantitative and qualitative risk assessments should always be buffered with careful professional judgment. If every statement was certain, we would not need a risk assessment. The need to balance risks with uncertainty can lead assessors to concentrate more on the uncertainty than on known facts that may affect impact potential. Risks identified for nonnative, invasive, large constrictor species (and other nonnative, invasive species besides large constrictors) in other regions often provide the justification in applying management measures to reduce risks in regions where the species have not yet been introduced. Thus, risk assessments should concentrate on evaluating potential risk.

Uncertainty, as it relates to the individual risk assessment, can be divided into three distinct types: (a) Uncertainty of the process (method); (b) uncertainty of the assessor(s) (human error); and (c) uncertainty about the organism (biological and environmental unknowns). All three types of uncertainty will continue to exist regardless of future developments. The inferential estimation of organism risk can be rated using high, medium, or low. The biological and other information assembled under each element will drive the process, forcing the assessor to use the biological information as the basis for his or her decision. Thus, the process remains transparent for peer review. The high, medium, and low ratings of the individual elements contributing to the probability of organism establishment (such as organism with pathway, entry potential, colonization potential, and spread potential) cannot be defined or measured: The assessor has to use professional judgment because the values of the elements contained under “Probability of Establishment” are not independent of the rating of the “Consequences of Establishment.”

Specific traits or biological characteristics were assessed for each snake species to arrive at each high, medium, or low rating. The strength of the analysis is not in the element-rating but in the detailed biological and other relevant information that supports the rating. Reed and Rodda (2009) followed the ANSTF 1996 (see Lacey Act Evaluation Criteria section, above, for explanation of this method) guidelines for combining scores and noting that certainty levels for each component of the process were followed by the risk assessors. The logic that was applied to develop every step of the risk assessment analysis can be found in Chapter Ten of Reed and Rodda (2009).

Comment PR3:

[Refers to previously listed species; see 77 FR 3330, January 23, 2012]

Comment PR4:

[Refers to previously listed species; see 77 FR 3330, January 23, 2012]

Comment PR5:

The term “zoological” is ambiguous and could lead to a potential loophole for those activities for which permitted importation could be allowed; hence, any activity pertaining to these snakes could be claimed to be “zoological.”

Response PR5:

This rulemaking addresses whether the identified species of large constrictor snakes qualify as injurious and, therefore, should be added to the list of injurious reptiles. The rule does not address under what circumstances a person may qualify for exception to the importation or interstate transportation prohibitions under the zoological purposes provisions. Therefore, this comment is outside of the scope of this rulemaking.

Public Comments

We reviewed all comments we received from the public, particularly for substantive issues and new information regarding the March 12, 2010, proposed rule to list the nine large constrictor snakes. Therefore, the public comments generally refer to the nine species in the proposed rule, unless otherwise stated, and we respond for all nine species, unless otherwise stated. Because some of the comments referred only to those constrictor snake species we listed on January 23, 2012 (77 FR 3330), we omit those comments from this final rule; we summarize and respond to them in the January 23, 2012, final rule to list the Burmese python and three other species. We consolidated the following comments and our responses into key issues that are not in any particular order.

Health and Welfare of Human Beings

(1)

Comment:

Some people have been killed and more have been injured in the United States by nonnative large constrictor snakes that were kept as pets.

Our Response:

The Humane Society of the United States submitted a list of 577 reports that included accounts of human injuries and fatalities from nonnative constrictor snakes, nonnative constrictor snakes that escaped or were spotted in the wild, and nonnative constrictor snakes kept in inhumane conditions that were reported in the media that occurred in the United States between 1978 and mid-2014. The accounts included reports of Burmese pythons, African (rock) pythons, reticulated pythons, boa constrictors, green anacondas, and yellow anacondas, and unidentified large constrictor snakes. The list contains accounts from 46 States, including Alaska and Hawaii. The reports included dozens of attacks on people, 14 of which resulted in human fatalities. Burmese python attacks reportedly resulted in five deaths. African (rock) pythons (not distinguished by species) reportedly attacked one person fatally. Reticulated python attacks reportedly resulted in the deaths of seven people. A 25-pound red-tailed boa constrictor killed a 34-year-old man.

USARK's Web site posts this statement under their “Best Management Practices” Web page (USARK 2014): “We understand that there are occupational hazards involved in the captive husbandry of the largest examples of five large snake species, and venomous reptiles. It is the position of USARK that only experienced and serious keepers should work with these animals.”

We acknowledge reports of deaths and injury due to encounters with nonnative large constrictor snakes, but the accounts identified by the commenter involved snakes held in captivity. Human fatalities from nonvenomous snakes in the wild are rare (Reed and Rodda 2009). An indirect risk is that large snakes may stretch across roads to obtain heat from the pavement on cool days, posing a hazard to motorists who swerve to avoid hitting them (Snow

et al.

2007; Harvey

et al.

2008). Please see “

Potential Impacts to Humans”

in the “Factors That Contribute to Injuriousness * * *” section for each species, above, for further information.

(2)

Comment:

The actual physical danger that large constrictors pose to humans and public safety has been grossly overstated, and only 12 human fatalities have been attributed to these snakes since 1980, an average of 0.4 deaths per year. Those fatalities are usually a direct result of either improper care and handling of the animal, or feeding-related errors on the part of the keeper or pet owner. Another commenter stated 10 human fatalities occurred from 1990 to 2012, or 0.43 per year, by captive constrictors.

Our Response:

We agree that, while 13 human deaths that we know of have occurred since 1980, this number is small relative to other causes of death. We agree that the preeminent issue is not one of public safety, because we know of few large constrictor snake attacks in the United States from free-ranging snakes. A study in Everglades National Park (Reed and Snow 2014) summarized occurrences of apparently unprovoked strikes to humans by large constrictors and the circumstances surrounding each of the five reported incidents, which occurred between 2006 and 2012. All strikes were from Burmese pythons and directed toward biologists moving through flooded wetlands; two strikes resulted in minor injury and three in no injury. No strikes are known to have been directed at park visitors. The study concludes that, while risks to humans should not be completely discounted, the relative risk of a human being killed by a python in Everglades National Park appears to be extremely low. We also note that, in their native ranges, reports of large constrictor snake attacks on humans in the wild are rare, although they have occurred (Reed and Rodda 2009). However, the remoteness of the native ranges of any of the species may preclude deaths from being reported. A study of a small tribe of hunter-gathers (the Agta) in the Philippines summarized attacks by reticulated pythons (Headland and Greene 2011). Of 19 rural men and women attacked, 11 died. While Reed and Rodda (2009) also state that virtually all known human fatalities are associated with pet manipulation, Snow

et al.

(2007) and Harvey

et al.

(2008) noted that large constrictors crossing roads could cause traffic accidents. In general, we agree that the risk to human safety is not in itself a substantial factor in listing any of these species as injurious. See also our response to Comment 1.

(3)

Comment:

Boa constrictors should be removed from the rule. These snakes have never killed their keepers, nor have they killed anyone else. There has never been a documented human death by a boa constrictor.

Our Response:

For reasons discussed above in the section Withdrawal of the Boa Constrictor from Consideration as an Injurious Species, we are withdrawing our proposal to list the boa constrictor as an injurious reptile (75 FR 11808; March 12, 2010).

Large Constrictor Snakes as Pets and Hobby

(4)

Comment:

Most people in the reptile hobby who choose to own these larger species are very responsible and do well in keeping their pets and investments healthy and safe, and this includes preventing their escape. It does not stand to reason that the actions of this very limited amount of negligent owners should affect millions of responsible pet owners.

Our Response:

While we do not dispute that most constrictor snake owners try to be responsible, the volume of imports and domestically bred snakes is large enough (averaging 29,520 annually (for 2011 to 2013) for the four species that are being listed in this final rule and the boa constrictor; of that, 6,135 for the four species that are being listed this final rule; Final Economic Analysis 2015, Table 8) that accidents do happen, resulting in snakes escaping or snakes being intentionally released. Shipping containers may be damaged—and live snakes able to escape—anywhere between the port of import and the destination of the pet owner's home. In that case, the problem could arise before the pet owners acquire the animals.

Another consideration is the risk involved with transporting large, powerful snakes. While keeping a snake in a sedentary home cage may not in itself be a difficult task, the situation may change when a 20-ft (6-m) snake weighing 200 pounds (91 kg) is transported in a car to a veterinarian. Unless the snake is transported in an escape-proof cage from the house to the automobile to the veterinarian, snakes may find more opportunities for escape. Conversely, small snakes may escape more easily than large ones because they are more likely to be transported casually, such as carried for show. For example, a boa constrictor that was transported around on its owner's neck on a Boston subway escaped and survived for a month on the heated train in January 2011 before being captured (Associated Press 2011).

We have based our determination on our evaluation of injuriousness to wildlife and wildlife resources and the likelihood that any of the four large constrictor snakes could escape, become established, and cause harm.

(5)

Comment:

These snakes are not injurious wild animals. They are domesticated pets.

Our Response:

We recognize that many snakes are kept in captivity with no negative incidences and that they seem tame. However, the fact that various species of wildlife may be kept as pets does not remove these species from the scope of U.S. wildlife laws. Under the injurious wildlife provisions of the Lacey Act (18 U.S.C. 42), all four of these species are wild. Therefore, we have the authority to list all of the four species of constrictor snakes once we determine that they are injurious. We base our determination as injurious on their effect on any one of the following: the interests of human beings, agriculture, horticulture, forestry, wildlife, or wildlife resources of the United States.

(6)

Comment:

I have kept more of these animals than anyone you will ever meet, and I can assure you, they are not injurious in any way.

Our Response:

We recognize that there are various meanings of “injurious.” However, under the Service's authority, the Lacey Act (18 U.S.C. 42), and for the purpose of this rule, injurious wildlife are wild mammals, wild birds, amphibians, reptiles, fish, crustaceans, mollusks, and their offspring or gametes that are injurious to the interests of human beings, agriculture, horticulture, forestry, wildlife, or wildlife resources of the United States. A wildlife species

does not need to be injurious to all of the above interests to be listed. If a species is injurious to wildlife or wildlife resources of the United States (including its territories and insular possessions), we have the authority to list that species.

(7)

Comment:

We agree that ownership of certain animals should be restricted; however, we feel that banning the species

Boa constrictor

fails to address current concerns, is unnecessarily restrictive, and counterproductive. This species also represents the largest portion of the nine species proposed for listing as injurious.

Our Response:

For reasons discussed above in the section Withdrawal of the Boa Constrictor from Consideration as an Injurious Species, we are withdrawing our proposal to list the boa constrictor as an injurious reptile (75 FR 11808; March 12, 2010).

(8)

Comment:

This rule will destroy the ability of animal hobbyists, who are our future biologists and conservationists, to explore and learn about these specific animals, thus limiting exposure to the natural world at large.

Our Response:

The commenters did not explain how the rule will destroy the ability of animal hobbyists to learn about these animals. Hobbyists will still be allowed to keep their snakes and offspring, and to acquire additional ones within their State (and consistent with their State's own laws). The long lives of these species improve the chances that the hobbyists will have their pets for one or more decades, generally much longer than amphibian and tropical fish hobbyists. Hobbyists still have many other species of snakes and other reptiles to choose from that are not listed as injurious. We hope that, with this rule, future biologists and conservationists will learn about the ecological role of these species in their native lands and in lands where they become invasive.

(9)

Comment:

A number of commenters in active duty in the military and who live off base stated that their snakes help them to cope with stress from traumatic events. If they get transferred, they will not be able to bring their pet snakes.

Our Response:

The commenters are correct that, if they are transferred, they could not transport their pet snakes, unless the transfer is to a location in the same State.

Unprecedented Regulation

(10a)

Comment:

A ban placed by the government on a group of animals that is so prevalent in the pet industry and kept by so many hobbyists would be unprecedented.

(10b)

Comment:

Other widely held pets have been banned by the Federal Government. For example, in 1975, the Food and Drug Administration (FDA) banned the sale or distribution of turtles with shells that measure less than 4 inches in length in response to findings that pet turtles were responsible for a substantial number of

Salmonella

infections nationwide. These were primarily the baby red-eared sliders (

Trachemys scripta

) that were commonly sold in pet stores in the 1950s, '60s, and '70s, and even given away for free.

Our Response:

The Lacey Act does not preclude listing a species that is prevalent in the pet industry, provided that the species meets the criteria for injuriousness. In addition, this regulation is not a ban on possessing or selling any of the species. Other animals in the pet trade have been banned by the Federal Government. For example, with the Wild Bird Conservation Act of 1992 (16 U.S.C. 4901

et seq.

), Congress banned imports of many exotic bird species that were common in the pet trade to ensure that their native populations are not harmed by international trade. Another example is the Food and Drug Administration banning small turtles common in the pet trade (see Comment 10b). States may also have their own restrictions, and these restrictions may be more stringent than this Federal rule. For example, individual States may ban possession of any of these snake species. This final rule only establishes a prohibition against importation and interstate transportation of listed species without a permit. Furthermore, only one of the species that we are listing (reticulated python) is regularly in the reptile trade, although infrequently; the other three constrictor species are rarely or not traded. Lastly, the establishment of the Burmese python (listed as injurious in a final rule we published on January 23, 2012, at 77 FR 3330) in South Florida is unprecedented anywhere in the United States for a large predator from the pet trade and demonstrates what could happen if other large constrictors have the opportunity to establish. Oftentimes, such new situations call for more stringent solutions than previously adopted.

Other Animals More Injurious

(11)

Comment:

A better argument based on safety and health statistics could be made to ban horses or dogs, as the average American is more likely to be injured or killed by either of those animals than any reptile. Certainly there are other species, such as feral cats, dogs, rats, pigeons, starlings, and pigs, that each cause more damage to the environment of South Florida.

Our Response:

As the commenter correctly points out, many species of feral domesticated animals are considered invasive and have caused harm to humans and natural resources in south Florida and other parts of the United States. However, under the Lacey Act, the Service has the authority only to list “wild” birds and “wild” mammals as injurious wildlife; under 18 U.S.C. 42(a)(2), the term “wild” is specific to any animals that, whether or not raised in captivity, are normally found in a wild state. Dogs, cats, and horses are considered domesticated animals under our regulations at 50 CFR 14.4 and, therefore, cannot be listed as injurious wildlife.

Based on the best available information, we have found that the four species covered by this final rule are injurious to human beings, to the interests of agriculture, or to the wildlife or wildlife resources of the United States. This does not mean that we believe these snakes to be the most injurious of all wild animals.

Effort To Ban Pets

(12)

Comment:

This snake ban opens the door to many other animals being banned. If this rule is passed, then next it will be foreign reptiles all together, followed closely by a different ban, followed by an eventual ban on reptiles, period. Next it will be cats, dogs, fish, and birds.

Our Response:

This rule does not ban possession of any species. As stated above in the

SUMMARY

and elsewhere in this rule, this rule prohibits only the importation into the United States and interstate transportation of reticulated python, DeSchauensee's anaconda, green anaconda, and Beni anaconda. Prohibiting importation and interstate transportation is the only authority provided to the Secretary of the Interior by Congress under the injurious wildlife provisions of the Lacey Act (18 U.S.C. 42). Two of the four species of large constrictor snakes in this final rule are already in captivity in the United States and are available for acquisition within each State (unless otherwise regulated by your State's laws). In addition, any species under consideration for listing as injurious is evaluated on a case-by-case basis, using all available information relevant to whether it is or is not injurious. Therefore, this rule does not set up a trend to regulate any particular species or groups of species. Second, the Lacey Act does not provide the authority to list domesticated

mammals and birds as injurious; see our response to Comment 11 for more information. However, any reptile can be considered for injurious wildlife listing if it meets the listing criteria (see Lacey Act Evaluation Criteria, above, for explanation).

Effect of Rule on Welfare of Large Constrictor Snakes

(13)

Comment:

This rule change basically represents a death sentence for millions of reptiles in the United States. Many of these snakes will be abandoned and set free where they will surely suffer and die.

Our Response:

We disagree that this rulemaking will result in the death of millions of reptiles currently being held in captivity. We have been clear that all owners of any of the snakes listed as injurious will be allowed to keep them under this rule. For animals already in the United States, this rule only restricts transport between States. We emphasize that it will be lawful for pet owners to keep their pets (if allowed by State law). Therefore, we have no reason to believe that responsible, caring owners will kill or release them into the wild. Breeders may still be able to export through a port in their own State (see response to Comment 68 for exporting explanation). For breeders who can no longer export, they may find buyers in their own State. For information on how to find a home for a snake that a person can no longer keep, we posted some suggestions on

http://www.regulations.gov

at the time the proposed rule was published on March 12, 2010 (separate file “Questions and Answers”). We explained:

“If you are in a position where you must give up your pet [large constrictor snake], and zoos and humane societies have declined your efforts to donate the animal, you should contact either your State fish and wildlife agency or your local U.S. Fish and Wildlife Service office. These two government agencies are the legal authorities that co-manage fish and wildlife in this country, and they can help you to resolve this issue. The U.S. Fish and Wildlife Service is working with States around the country and the pet and aquarium industry through a campaign called Habitattitude

TM

to help pet owners adopt environmentally responsible actions for surrendering their pets, such as:

• Contacting the retailer for proper handling advice or for possible return;

• Giving or trading with another pet owner;

• Donating to a zoo, humane society, nature center, school, or pet retailer; and

• Contacting a veterinarian or pet retailer for guidance on humane disposal of animals.”

For those pet owners who move to another State, we also suggest contacting a local herpetology club or a national reptile organization with local members to find someone to adopt those constrictor snakes. And finally, if you live in Florida, “Anyone who possesses a conditional snake or lizard but cannot keep it can surrender the animal to a licensed recipient (adopter) at any time with no penalties” (FWC 2014).

(14)

Comment:

What would happen to the businesses operated by thousands of families in the industry with this rule? It is doubtful that those animals would be humanely euthanized (due to finances and ethical objections), so those animals would either be subjected to inhumane practices or become liabilities to those persons who have them. It would be a cruel irony that the animal rights agenda of eliminating these animals from the pet trade would result in the destruction of millions of animals that have proven to be nondangerous.

Our Response:

Family businesses will still be able to operate, provided they either sell within their State or have a port of export directly from their State (see response to Comment 68 for exporting explanation). Businesses may switch to other species of snakes that are not listed. Please see our response to Comment 13 on alternatives for disposing of animals that you can no longer keep. Owners are encouraged to find legal alternatives, such as trading species with someone in their own State who has a species that is not listed and who is able to keep a listed species in that State. We emphasize that it will be lawful for pet owners to keep their pets (if allowed by State law) but unlawful to transport them across State lines. With the removal of the boa constrictor from consideration for listing, the effect to businesses is greatly reduced.

Regarding the statement that these snakes are nondangerous, we emphasize that we distinguish between “nondangerous,” which we assume the commenter means “does not harm people,” and “injurious,” which has a different meaning under the Lacey Act. We agree that these four species of snakes pose only a small risk of harm to people; however, we are listing them for their injuriousness.

(15)

Comment:

Thousands of snakes' lives will be spared because the majority of reptiles die during capture from the wild or subsequent transport or within the first year of captivity. Banning the importation of these species will ensure that many snakes will not fall victim to the harsh conditions of being shipped overseas. Snakes are often marketed as low-maintenance pets, and the families who take them home can become overwhelmed at the level of care required.

Our Response:

From the Service's Law Enforcement Management Information System (LEMIS) data, we estimate that approximately 26,591 snakes of the four species we are listing in this rule were imported from 2004 to 2013. Some were probably captured from the wild. Imported snakes are then usually sent to animal dealers before being shipped to pet retailers. Finally, the snakes are typically acquired at a pet retailer and transported to a home or other location. Large constrictor snakes may become ill, injured, or die during transport. Since this listing will place prohibitions on importation and interstate movement of the four species, it is reasonable to assume that fewer animals will therefore die from importation and interstate transport. Although animal welfare is regulated by the Federal Government for some taxa (that is, primarily warm-blooded species) under such laws as the Animal Welfare Act (7 U.S.C. 2131

et seq.

), this was not a factor considered in our injurious wildlife evaluation and did not influence our final determination.

Benefits of H

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