# Endangered and Threatened Wildlife and Plants; Threatened Species Status for the Rufa Red Knot

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2014-28338

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** December 11, 2014
- **Citation:** 79 FR 73706

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R5-ES-2013-0097; 4500030113]
RIN 1018-AY17
Endangered and Threatened Wildlife and Plants; Threatened Species Status for the Rufa Red Knot

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), determine threatened species status under the Endangered Species Act of 1973 (Act), as amended, for the rufa red knot (
Calidris canutus rufa
). The rufa red knot is a migratory shorebird that breeds in the Canadian Arctic, winters in parts of the United States, the Caribbean, and South America, and primarily uses well-known spring and fall stopover areas on the Atlantic coast of the United States, although some follow a midcontinental migratory route. The effect of this regulation will be to add this species to the list of Endangered and Threatened Wildlife.

DATES:

This rule becomes effective January 12, 2015.

ADDRESSES:

This final rule is available on the internet at
http://www.regulations.gov
at Docket Number FWS-R5-ES-2013-0097 and at
http://www.fws.gov/northeast/redknot/.
Comments and materials we received, as well as supporting documentation we used in preparing this rule, are available for public inspection at
http://www.regulations.gov.
All of the comments, materials, and documentation that we considered in this rulemaking are available by appointment, during normal business hours at: U.S. Fish and Wildlife Service, New Jersey Field Office (see
FOR FURTHER INFORMATION CONTACT
).

FOR FURTHER INFORMATION CONTACT:

Eric Schrading, Field Supervisor, U.S. Fish and Wildlife Service, New Jersey Field Office, 927 North Main Street, Building D, Pleasantville, New Jersey 08232, by telephone 609-383-3938 or by facsimile 609-646-0352. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.
Under the Endangered Species Act, a species may warrant protection through listing if it is endangered or threatened throughout all or a significant portion of its range. Listing a species as an endangered or threatened species can only be completed by issuing a rule.

This rule will
finalize the listing of the rufa red knot (
Calidris canutus rufa
) as a threatened species.

The basis for our action.
Under the Endangered Species Act, we may determine that a species is an endangered or threatened species based on any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) Overutilization for commercial, recreational, scientific, or educational purposes; (C) Disease or predation; (D) The inadequacy of existing regulatory mechanisms; or (E) Other natural or manmade factors affecting its continued existence. We have determined that the rufa red knot is a threatened species due to loss of both breeding and nonbreeding habitat; likely effects related to disruption of natural predator cycles on the breeding grounds; reduced prey availability throughout the nonbreeding range; and increasing frequency and severity of asynchronies (mismatches) in the timing of the birds' annual migratory cycle relative to favorable food and weather conditions.

Peer review and public comment.
We sought comments from three independent specialists with expertise on red knot biology and sea level rise to ensure that our designation is based on scientifically sound data, assumptions, and analyses. We invited these peer reviewers to comment on our listing proposal. Only one of the three peer reviewers provided comments on the proposal. This peer reviewer was generally supportive of the proposal, and provided substantive comments and documentation regarding biological differences between red knots in northern versus southern wintering areas. Many of these differences were already in the proposal but in separate locations; we consolidated and emphasized these differences, updating as appropriate with new information.

Previous Federal Action

Please refer to the proposed listing rule for the rufa red knot (78 FR 60024; September 30, 2013) and its Previous Actions supplement available online at
www.regulations.gov
under Docket Number FWS-R5-ES-2013-0097 for a detailed description of previous Federal actions concerning this species.

Background

Species Information

The rufa red knot (
Calidris canutus rufa
) is a medium-sized shorebird about 9 to 11 inches (in) (23 to 28 centimeters (cm)) in length. (Throughout this document, “rufa red knot,” “red knot,” and “knot” are used interchangeably to refer to the
rufa
subspecies. “
Calidris canutus”
and “
C. canutus”
are used to refer to the species as a whole or to birds of unknown subspecies. References to other particular subspecies are so indicated.) The red knot migrates annually between its breeding grounds in the Canadian Arctic and several wintering regions, including the Southeast United States (Southeast), the Northeast Gulf of Mexico, northern Brazil, and Tierra del Fuego at the southern tip of South America. During both the northbound (spring) and southbound (fall) migrations, red knots use key staging and stopover areas to rest and feed.

The November 2014 Rufa Red Knot Background Information and Threats Assessment (Supplemental Document; Service 2014, entire), available online at
www.regulations.gov
under Docket Number FWS-R5-ES-2013-0097, provides a thorough assessment of the rufa red knot biology and ecology, historical distribution and abundance, population surveys and estimates, and threats to its survival. The Supplemental Document has been updated since the September 30, 2013 publication of the proposed rule with data received during the peer review and public comment processes and relevant scientific data that have become available. In the Supplemental Document, we compile biological data and a description of past, present, and likely future threats facing the red knot. Because data in these areas of science can be limited, some uncertainties are associated with the data and conclusions drawn from the data. We have attempted to clearly identify these uncertainties and assumptions, which are based on the best available scientific and commercial data, explicit in the Supplemental Document. The Supplemental Document provides the scientific basis for our decision (see Summary of Biological Status and Threats in this final rule), the legal basis for which is the Act and its regulations and policies (see Determination in this final rule).

Summary of Biological Status and Threats

In this section, we summarize the population and threats information previously provided in the proposed

rule (78 FR 60024; September 30, 2013) and updated as appropriate from new information received since the proposed rule's publication. See the Summary of Changes from the Proposed Rule section below for what has been updated.

We note that the proposed rule referenced four separate documents of supporting material—Previous Federal Actions, Rufa Red Knot Ecology and Abundance, Climate Change Background, and Factor D: The Inadequacy of Existing Regulatory Mechanisms. For this final rule, we have combined those documents into one Supplemental Document. From here forward, when we are referencing information in the proposed rule, we will use the proposed rule's
Federal Register
citation and page number (
e.g.,
78 FR 60024, p. 60032); when we are referencing information in one of the proposed rule's supporting documents, we will use the document's name and page number (
e.g.,
Rufa Red Knot Ecology and Abundance, p. 5); and when we are referencing information now contained in the final rule's Supplemental Document, we will use the Supplemental Document's title and section (
e.g.,
Supplemental Document, Factor E—Reduced Food Availability—Horseshoe Crab Harvest).

Population Information:
After a thorough review of the best available population data, we conclude that we do not have sufficient reliable data on which to derive a precise rangewide population estimate for the rufa red knot. For example, there are no rangewide population estimates for fall migration or breeding areas because birds are too dispersed. We have limited confidence in any population trends inferred from wintering areas in Brazil's north coast, the northern Gulf coast, and the Southeast United States because available data from these areas vary in geographic coverage, methods, and level of effort. However, there are several areas where surveys have been conducted using more consistent observers, methods, and geographic coverage: Tierra del Fuego and the Argentine coast (winter), Delaware Bay (spring), the east coast of South America (spring), and Virginia (spring).

For Tierra del Fuego, baseline population data are available from the 1980s, and annual counts are available from 2000 to 2013, all collected with the same methodology and surveyors. The most recent counts (2011 to 2013) are about 75 percent lower than the 1980s baseline. The annual counts (2000 to 2013) show that the decline began after 2000, but the population has apparently stabilized at a low level since 2011.

For Delaware Bay, baseline data are available from the early 1980s, and annual peak counts are available for 1986 to 2014. The core years of 1986 to 2008 were collected with consistent methodology and surveyors. Based on these data, there may have been declines in the Delaware Bay stopover population in the 1990s, but variability in the data makes it difficult to detect trends. In contrast, the decline in Delaware Bay red knot counts in the 2000s was sufficiently pronounced and sustained that we have confidence in the downward trend over this time period despite the variability in the data. The average of peak counts in Delaware Bay over the past decade (2005 to 2014) was about 70 percent lower than the 1980s baseline. However, Delaware Bay numbers appear to have stabilized or increased slightly from 2009 to 2014, despite our lower confidence in the data over this later period due to shifts in methodology and surveyors.

Data sets from three South American Atlantic coast spring stopovers also suggest declines roughly over this same timeframe (early 2000s relative to 1990s). We previously concluded that the Virginia spring stopover had been stable since the mid-1990s, but new information now indicates a decline in Virginia relative to the 1990s.

In summary, our analysis of the best available data concludes that an overall, sustained decline of red knot numbers occurred at Tierra del Fuego and Delaware Bay in the 2000s, and that these red knot populations may have stabilized at a relatively low level in the last few years. Although we lack sufficiently robust data to conclude if other wintering and stopover areas also declined, we conclude it is likely that declines at Tierra del Fuego and Delaware Bay drove an overall population decline (
i.e.,
lower total numbers), because these two sites supported a large majority of rangewide knots during the baseline 1980s period. This conclusion is consistent with efforts (by others) to evaluate long-term population trends using national or regional data from volunteer shorebird surveys and other sources, which have also generally concluded that red knot numbers have declined. Please refer to this final rule's Supplemental Document—Population Surveys and Estimates for a more detailed discussion of the population information available for the rufa red knot throughout its range, available online at
www.regulations.gov
under Docket FWS-R5-ES-2013-0097.

Threats:
Substantial threats exist throughout the red knot's breeding, migration, and wintering range and these threats are likely to continue or intensify into the future. For a full discussion of the five factors (
i.e.,
Factors A, B, C, D, and E) assessed as a basis for making the listing determination, please see the Supplemental Document—Summary of Factors Affecting the Species available online at
www.regulations.gov
under Docket Number FWS-R5-ES-2013-0097. A summary is provided below:

(1) Past habitat losses in wintering and migration areas have reduced the resilience of the red knot (Factor A). Ongoing losses in these areas from sea level rise, shoreline hardening, and development are expected to continue into the coming decades (Factor A). Beach nourishment can be beneficial or detrimental to red knot habitat, though any negative effects are mostly considered to be short-term. More recently, vegetation and ecosystem changes resulting from climate change, and potentially from development, have begun to threaten habitat loss on the breeding grounds as well (Factor A).

(2) Threats to the current and future quality and quantity of prey resources occur throughout the red knot's range from climate change and other causes (
e.g.,
ocean acidification; warming coastal waters; marine diseases, parasites, and invasive species; sediment placement; recreation; and fisheries) (Factor E). Reduced food availability in Delaware Bay due to commercial harvest of the horseshoe crab (
Limulus polyphemus
) (HSC) is considered a primary causal factor in red knot population declines in the 2000s. (Red knots rely on horseshoe crab eggs as food during their spring stopover in Delaware Bay.) We do not consider the HSC harvest a threat under the science-based management framework that has been developed and adopted to explicitly link harvest quotas to red knot population growth (Factor D). However, HSC monitoring necessary for the implementation of the management framework was not conducted in 2013 or 2014 due to lack of funding; thus, the framework is not currently being implemented as it was intended to function. There is uncertainty regarding implementation of the framework in the future (Factor D). While we anticipate a fully functioning management framework would continue to adequately abate the threat to red knots from the HSC harvest, there are other biological factors independent of harvest that may limit the availability of HSC eggs into the future. For example, HSC population growth may be limited by a biological lag time because HSCs take up to 10-years to become sexually

mature and therefore it may take at least that long for harvest restrictions (which have been phased in since 2000) to produce a corresponding increase in HSC populations. Other factors (
e.g.,
early life stage mortality, undocumented or underreported mortality) may also be slowing HSC population growth (Factor E). Most data suggest that the volume of horseshoe crab eggs is currently sufficient to support the Delaware Bay's stopover population of red knots at its present size. However, because of the uncertain trajectory of horseshoe crab population growth, it is not yet known if the HSC egg resource will continue to adequately support red knot population growth over the next decade.

(3) The red knot faces ongoing and future increases in asynchronies (timing mismatches) throughout its migration and breeding range as a result of climate change and unknown causes (Factor E). Successful annual migration and breeding of red knots is highly dependent on the timing of departures and arrivals to coincide with favorable food and weather conditions in the spring and fall migratory stopover areas and on the Arctic breeding grounds (Factor E).

(4) On the arctic breeding grounds, normal 3- to 4-year cycles of high predation, mediated by rodent (
e.g.,
lemming) cycles, result in years with low reproductive output of red knots (in some years it is zero), but do not threaten the survival of the red knot at the subspecies level (Factor C). That is, when lemmings are abundant, predators (
e.g.,
arctic fox) concentrate on the lemmings, and shorebirds breed successfully, but when lemmings are in short supply, predators switch to shorebird eggs and chicks (Niles
et al.
2008, p. 101; COSEWIC 2007, p. 19; Meltofte
et al.
2007, p. 21; USFWS 2003, p. 23; Blomqvist
et al.
2002, p. 152; Summers and Underhill 1987, p. 169). It is believed shorebirds, such as red knots, have adapted to these cycles, therefore these natural cycles are not considered a threat to the red knot. What is a threat, however, is that these natural rodent/predator cycles are being disrupted by climate change, which may increase predation rates on shorebirds over the long term and have subspecies-level effects (Factor C and Factor E) (Chapter 28
in
IPCC 2014, p. 14; Fraser
et al.
2013, pp. 13, 16; Brommer
et al.
2010, p. 577; Ims
et al.
2008, p. 79; Kausrud
et al.
2008, p. 98). The documented collapse or dampening of rodent (
e.g.,
lemmings) population cycles of over the last 20 to 30 years in parts of the Arctic can be attributed to climate change with “high confidence” (Chapter 28
in
IPCC 2014, p. 14). We conclude that disruptions in the rodent/predator cycle pose a substantial threat to the red knot, as they may result in prolonged periods of low reproductive output of red knots due to increased predation (Factor C). The substantial impacts of elevated egg and chick predation on shorebird reproduction are well known. Disruptions in the rodent/predator cycle may have already affected red knot populations and are likely to increase due to climate change (Factor C).

Other factors may cause additive red knot mortality. Individually these factors are not expected to have subspecies level effects; however, cumulatively, these factors could exacerbate the effects of the primary threats if they further reduce the species' resiliency. These secondary factors include hunting (Factor B); predation in nonbreeding areas (Factor C); and human disturbance, oil spills, and wind energy development especially near the coasts (Factor E).

In summary, the rufa red knot faces numerous threats across its range on multiple geographic and temporal scales. These threats are affecting the subspecies now and will continue to have subspecies-level effects into the future.

Summary of Changes From the Proposed Rule

The following minor but substantive changes have been made to the listing rule and the Supplemental Document (available online at
www.regulations.gov
under Docket FWS-R5-ES-2013-0097) based on new information that has become available since the publication of the proposed rule, including information received through peer review and public comments. These changes did not alter our previous assessment of the rufa red knot from the proposed rule to the final rule.

(1) We present new data and insights regarding the nonbreeding distributions of rufa red knots versus
Calidris canutus roselaari.

(2) We have emphasized and consolidated information about the differences between rufa red knots from northern versus southern wintering areas.

(3) We have added new geolocator data and new analyses of available resightings data showing (a) movement of rufa red knots between the North American Central and Atlantic Flyways; (b) clusters of sightings along the Great Lakes, the Mississippi River and its tributaries, and other major water bodies away from the coasts; (c) apparent use of saline (or alkaline) lakes in the Northern Plains by northbound red knots using the Central Flyway; and (d) use of U.S. Atlantic coast habitats used by juveniles in summer and winter.

(4) We updated population information with winter counts in South America and the southeast United States. The 2013 red knot winter counts in Tierra del Fuego were down to the second lowest level on record, while the counts in northern Brazil were nearly double the previous high count recorded in 1986. The large number of knots found in Brazil in 2013 was likely the result of the survey team experiencing favorable tidal conditions throughout the survey period, and this is probably the team's best aerial survey estimate to date. In addition, a new report from the Georgia Department of Natural Resources (GDNR) based on mark-recapture mathematical models estimated that the northern wintering population may be around 20,000 birds; this number is consistent with some previous estimates but notably higher than the best available field survey from the Southeast of about 4,000 to 5,000 birds. However, we do not yet have information to determine whether the geographic extent of the “northern” population in the GDNR study includes areas outside the Southeast.

(5) We updated our analysis of climate change information based on new reports from the International Panel on Climate Change (IPCC) and National Climate Assessment. Updates include:

(a) The IPCC's increased certainty in the overall trajectory of global and regional climate changes over the next few decades.

(b) Recent assessments of the red knot's vulnerability to climate change indicating a large increase in extinction risk due to the likely loss of breeding (from arctic warming) and nonbreeding habitat (from sea level rise), as well as the red knot's high degree of habitat specialization and dependence on ecological synchronicities, and long migration distance.

(c) New reports finding, with high certainty, that arctic ecosystem changes are already under way and will continue, in some cases faster than previously anticipated. (The IPCC notes early warning signs that arctic ecosystems are already experiencing irreversible regime shifts.)

(d) A new conclusion by the IPCC that the documented collapse or dampening of rodent population cycles in some parts of the Arctic over the last 20 to 30 years can be attributed to climate change with “high confidence.”

(e) An updated analysis of threats to red knot prey species from ocean acidification, temperature changes, and other aspects of climate change. (A new

report highlights the vulnerability of mollusks (which include the red knot's primary prey species in most of its range) to acidification (“high confidence”).)

(6) We updated the best available data regarding current and likely future rates of sea level rise. We also noted a new study showing that expected effects to migratory shorebird populations from sea level rise are disproportionally larger than the extent of projected habitat loss, especially for species (such as red knots) whose migration routes contain “bottlenecks” through which a large fraction of the population passes.

(7) We discussed new voluntary, regulatory, or proposed restrictions on red knot hunting (
e.g.,
in Barbados, Guadeloupe, Martinique, and French Guiana), but acknowledged that best available data are insufficient to determine if hunting is or was at levels in South America that may have a population-level effect.

(8) We updated Federal and State authorities to regulate the importation of Asian HSC species, which may pose a threat to native HSC populations.

(9) We noted the results of the Atlantic States Marine Fisheries Commission's (ASMFC) 2013 HSC stock assessment update showing that, in the Delaware Bay Region, there is evidence of increases in certain age or sex classes, but overall population trends have been largely stable (neither increasing nor decreasing) since the previous stock assessment in 2009.

(10) We updated our analysis of possible undocumented or underestimated HSC mortality with new information on poaching, bycatch, and sublethal effects of biomedical bleeding.

(11) We updated the discussion as follows about the Adaptive Resource Management (ARM) monitoring efforts to reflect uncertainty (due to lack of funding) in ongoing implementation:

(a) We continue to conclude that, as long as the ARM is in place and functioning as intended, ongoing HSC bait harvests should not be a threat to the red knot.

(b) Data necessary to support the ARM previously came from an annual HSC trawl survey conducted by the Virginia Polytechnic Institute (Virginia Tech) that was ended after 2012 due to lack of funding. The ARM modelers are working on the best way to switch to another, newer survey, the North East Area Monitoring and Assessment Program (NEAMAP), and we support those efforts.

(c) As of fall 2014, however, these efforts have not identified a method by which NEAMAP or other alternate data sets can be appropriately used to allow the functioning of the ARM models (ASMFC 2014b). Stable funding sources for other baywide monitoring programs necessary to support the ARM are also a concern.

(d) If the ARM cannot be implemented in any given year, ASMFC would choose between two options based on which it determines to be more appropriate—either use the previous year's harvest levels (as previously set by the ARM), or revert to an earlier management regime. Although the HSC fishery would continue to be managed under either of these options, the explicit link to red knot populations would be lost.

(e) Insufficient monitoring has already impacted the ability of the ASMFC to implement the ARM as intended (ASMFC 2014b; ASMFC 2012c, p. 13). Absent the necessary HSC monitoring data to use the ARM models for the 2015 season, ASMFC (2014b) has opted to use the 2014 harvest levels which we considered at the time to adequately ensure the red knot's food supply.

(12) We updated our analysis of disturbance with new findings from two sites on the Atlantic coast of New Jersey, showing that disturbance affected red knots' spatial uses of these sites and displaced knots from otherwise suitable habitats.

(13) We reorganized the wind energy development discussion by moving general information on avian collision and displacement hazards to a background section, not specific to either offshore or terrestrial development. We updated this section with new information including a new report on avian vulnerability to offshore wind development. We updated our conclusions that collision and displacement risks per turbine (notwithstanding differences in specific factors such as turbine size, design, operation, and siting) are likely higher along the coasts than far inland or far offshore.

(14) We updated the 50 CFR 17.11 table to add Martinique and the District of Columbia. We received new information that red knots occur on Martinique. The District of Columbia was already included in the known range of the red knot, but was inadvertently left off the table in the proposed rule.

Summary of Comments and Recommendations

In the proposed rule published on September 30, 2013 (78 FR 60024), we requested that all interested parties submit written comments on the proposal by November 29, 2013. We also contacted appropriate Federal and State agencies, scientific experts and organizations, and other interested parties and invited them to comment on the proposal. A newspaper notice inviting general public comment was published in the USA Today on October 3, 2013. We received four requests for a public hearing. On April 4, 2014 (79 FR 18869), we reopened the comment period on the proposed rule until May 19, 2014, and announced that two public hearings would take place on May 6, 2014, in Corpus Christi, Texas, and Morehead City, North Carolina. On May 14, 2014 (79 FR 27548), we extended the public comment period until June 15, 2014, and announced that another public hearing would take place in Manteo, North Carolina on June 5, 2014. All substantive information provided during the comment periods is summarized above in the Summary of Changes from the Proposed Rule and has either been incorporated directly into this final determination or addressed in the more specific response to comments below.

A number of commenters, including a peer reviewer, Federal agencies, and States, provided new information or clarifications on information presented in the red knot proposed listing rule (78 FR 60024) and its supporting documents. Categories of new or clarified information include additional years of population estimates or sighting information throughout the rufa red knot's range, status of the rufa red knot and ecology in Argentina and French Guiana, beach cleaning, sea level rise and its projected effects on migratory shorebirds, disturbance, the Deepwater Horizon and Galveston oil spills, status of offshore wind energy development leases along the Atlantic coast, historical and current food resources and foraging habitat, migration and staging areas, updated stopover population size estimates in Delaware Bay, State restrictions on importing Asian HSC, ongoing management of HSC, habitat protection in Maine, and geolocator scope of inference. This new or clarified information has been incorporated, as appropriate, into this final rule or its Supplemental Document.

General Issues

(1) Comment:
Several public, State, and Federal commenters submitted comments on topics related to other issues not specific to the red knot listing proposal. These issues include (a) general criticism of the Act (funding species' conservation and Service employees being a target of litigation, imposing fines that are too punitive, having negative effects on local

communities, producing decisions on which species survive and where public hearings are held, and using science that would not withstand National Academy of Science Review); (b) the information and analysis required to designate critical habitat; and (c) red knot or HSC population targets, other species, research, actions, or resources that should be considered, as well as where funding should be directed and whom the Service should work with as part of ongoing or future conservation activities and recovery planning for the rufa red knot.

Our Response:
All of these comments are outside the scope of this final listing rule and will not be addressed here. Substantive comments related to critical habitat issues will be addressed during development of a proposed critical habitat rule for the red knot. Substantive comments related to future conservation of the red knot will be addressed during the development of a recovery outline and draft recovery plan.

(2) Comment:
Several commenters, including one State, expressed concerns that the rufa red knot's listing could (a) result in restrictions on pedestrian and vehicular beach recreation, additional regulatory hurdles, decreased property values, and increased costs to otherwise lawful activities, all of which could cause negative effects to local communities, economies, and quality of life, and could erode the current goodwill of partners to work on red knot conservation; (b) result in reduced HSC harvest levels, causing economic impacts to fishermen reliant on the HSC bait fishery, potentially shifting harvest pressure to areas outside of Delaware Bay, and potentially creating incentives to import Asian HSC species for bait; (c) reduce availability of HSCs for biomedical uses; and (d) restrict beach access for HSC conservation programs (
e.g.,
rescue programs for volunteers to flip stranded crabs). Additionally, some commenters expressed frustration over existing beach access and management on National Park Service (NPS) lands because of other listed species and asked for expanded management options beyond beach closures. Conversely, other commenters asked for additional restrictions in places like Delaware Bay.

Our Response:
While we appreciate the concern about potential management actions that may result from listing the rufa red knot or any species, the Act does not allow us to factor those concerns into our listing decision. Section 4(a)(1) of the Act specifies that we shall determine whether any species is threatened or endangered because of any of the following factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. Section 4(b)(1)(A) further specifies that we shall make such determinations based solely on the best scientific and commercial data available. See
Our Response 60
regarding other implications of listing that we may not consider in evaluating whether a species meets the definition of threatened or endangered under the Act.

The Service does not make management decisions about any lands other than National Wildlife Refuges and National Hatcheries, but we remain committed to working with coastal communities to evaluate any effects of coastal management on the rufa red knot, and to implement actions in a manner consistent with the species' conservation using many of the Act's available tools. We will strive to build on existing management practices in local areas to limit disturbance to red knots and other shorebirds through coordination and partnership with the States, other Federal agencies, conservation groups, and local communities.

The Service does not have authority to directly regulate the HSC fishery, but we intend to continue our active role in the ASMFC's management of the HSC fishery, and will provide recommendations and technical assistance to ensure that future harvests of HSCs do not result in take of red knots under section 9 of the Act. See
Our Responses 45, 46, 48 through 50, 52, 111, 117, 120, and 121
below and the Supplemental Document (Factor E—Reduced Food Availability—Horseshoe Crab Harvest) for detailed answers related to other aspects of HSC management, including biomedical use and implications of importation of Asian HSC species.

(3) Comment:
Several commenters asked how listing will benefit the red knot when its range spans several countries, yet the Act's jurisdiction is limited to the United States. Many of the threats discussed in the proposed rule either occur only in areas outside of the United States (
e.g.,
hunting) or are issues (
e.g.,
climate change) that cannot be affected by management under the Act. The Service cannot expect to achieve a fraction of the conservation success that has been achieved in Delaware Bay, given that the Act's prohibitions do not apply outside of the United States.

Our Response:
The Act requires listing of a species that meets the definition of threatened or endangered even if we currently lack the means to fully abate the threats that cause it to be threatened or endangered. Notwithstanding, we disagree that listing will have no effect on threats such as adequacy of food supplies and hunting, and we expect these threats to be addressed during recovery planning. The development of a recovery plan will guide efforts intended to ensure the long-term survival and eventual recovery of the rufa red knot, as discussed in the proposed rule (78 FR 60024, p. 60097). While we acknowledge that listing will not have a direct impact on those aspects of climate change impacting the rufa red knot (
e.g.,
sea level rise, arctic and ocean warming, ocean acidification, timing changes in the annual cycles of natural systems, possible changes in storm patterns or predation pressures), we expect that listing will enhance national and international cooperation and coordination of conservation efforts, enhance research programs, and encourage the development of mitigation measures that could help slow habitat loss and population declines.

Benefits to the species outside the United States from listing include a prohibition on import. By regulating this activity, the Act ensures that people under the jurisdiction of the United States do not contribute to the further decline of listed species. Although the Act's prohibitions regarding listed species apply only to people subject to the jurisdiction of the United States, the Act can generate additional conservation benefits such as increase awareness of listed species, encourage research efforts to address conservation needs, or prioritize funding for
in-situ
conservation of the species in its range countries. The Act also provides for limited financial assistance to develop and manage programs to conserve listed species in foreign countries, encourages conservation programs for such species, and allows for assistance for programs, such as personnel and training.

While we agree that limiting HSC harvests and other actions in Delaware Bay have been instrumental in halting (though not yet reversing) the decline of the red knot, we do not agree that conservation of this species is impossible in other geographic areas. For example, the rufa red knot is listed as endangered in Canada and Argentina, was recently protected from hunting in the Caribbean, has been listed as a

protected species in French Guiana, and is a focus of active conservation programs in several countries including Canada, Argentina, and Chile. In the United States, there are ongoing conservation and research efforts in many areas outside Delaware Bay including Massachusetts, Virginia, North Carolina, South Carolina, Georgia, Florida, and Texas. Many important red knot areas within and outside the United States have been recognized as Western Hemisphere Shorebird Reserve Network sites.

(4) Comment:
One commenter stated that the Act is currently under revision and it is advisable to postpone further listings until the changes are finalized.

Our Response:
While we are aware of several proposed legislative changes to the Act, those changes may not come to fruition and we may not delay implementing the current Act while those proposed changes are being debated. In addition to the proposed legislative changes, we are actively working on a series of regulatory changes to improve the implementation of the Act (see our “Improving ESA Implementation” Web site for more information:
http://www.fws.gov/endangered/improving_ESA/index.html
).

Peer Reviewer Comments

In accordance with our peer review policy published on July 1, 1994 (59 FR 34270), we solicited expert opinion from three knowledgeable individuals with scientific expertise that included familiarity with the rufa red knot and its habitat, biological needs, and threats. We received responses from one of the peer reviewers.

We reviewed all comments received from the peer reviewer for substantive issues and new information regarding the listing of the rufa red knot. This peer reviewer was generally supportive of the overall proposal and, in addition to providing further site-specific information, generally confirmed our use of the best available scientific information. Peer reviewer comments are addressed in the following summary and incorporated into the final rule as appropriate.

(5) Comment:
The peer reviewer stated there is nonscientifically reported evidence (newspaper articles, animal care center reports) that red tide poisoning has caused extensive death of knots on Florida's west coast.

Our Response:
We appreciate the peer reviewer bringing this information to our attention. Unfortunately, we were unable to locate the sources of the suggested information and, therefore, cannot verify the content. However, we have obtained a report of one nonfatal case of red tide poisoning of a red knot in Florida (H. Barron pers. comm. April 29, 2014); the bird's blood was tested and confirmed to have a brevetoxin level of 2.64 nanograms/milliliter (ng/ml). Brevetoxin is a highly potent neurotoxin produced by red tide events. We have added this information to the Supplemental Document (Factor E—Harmful Algal Blooms—Gulf of Mexico). Though not documenting widespread effects or mortality from red tide, this report does confirm that red tide poisoning of red knots has occurred in Florida, which is otherwise unreported in the scientific literature.

(6) Comment:
The peer reviewer noted that the proposed rule (78 FR 60024, p. 60045) states that uncontrolled invasive vegetation can cause a habitat shift from open or sparsely vegetated sand to dense vegetation, resulting in the loss or degradation of red knot roosting habitat. The link between dense invasive vegetation and red knot habitat degradation is conjecture and should be strengthened with reference to a scientific study.

Our Response:
We agree. We have revised this paragraph in the Supplemental Document (Factor A—Invasive Vegetation) to add citations to support the statement that uncontrolled invasive vegetation can cause a habitat shift from open or sparsely vegetated sand to dense vegetation. We have removed the wording “resulting in the loss or degradation of red knot roosting habitat,” because we are not aware of any scientific studies or other data documenting that such degradation has occurred. We have instead added the statement that, in nonbreeding habitats,
Calidris canutus
require sparse vegetation to avoid predation (Niles
et al.
2008, p. 44; Piersma
et al.
1993, pp. 338-339, 349).

(7) Comment:
The peer reviewer stated that the Southeast coast of the United States is important during northward migration. Many red knots marked in Argentina and Chile are seen on the Atlantic coasts of Florida, Georgia, South Carolina, and North Carolina during, but not before, May. In addition, several other commenters stated the proposed rule did not identify North Carolina as having major or important spring or fall stopover areas.

Our Response:
The Southeast, including North Carolina, was identified in the proposed rule as providing spring and fall stopover sites (Rufa Red Knot Ecology and Abundance, pp. 18, 50-51). Data characterizing the stopover usage of the Southeast, including North Carolina, are presented unchanged in the Supplemental Document (
e.g.,
figure 4; Population Surveys and Estimates—Spring Stopover Areas—Southeast United States). However, we have revised the text of the Supplemental Document (Population Surveys and Estimates—Spring Migration) to clarify that our review focused on geographically large spring stopovers with multiple years of survey data, but that other important spring stopover areas are known (
e.g.,
from International Shorebird Survey data, eBird, localized surveys). We have also revised the wording of the Supplemental Document (Migration—Atlantic Coast) to refer to “well-known” instead of “major” or “important” spring and fall stopover areas, since many potentially significant stopover areas have been surveyed only sporadically or are yet undiscovered. Finally, we have added the information provided by the peer reviewer regarding passage of southern-wintering birds along the Southeast coast during May (Migration—Atlantic Coast—Spring Timing and Distribution).

(8) Comment:
The peer reviewer stated the proposed rule presented comprehensive evidence about threats to red knots during winter and northbound migration seasons, mostly focused on the longest-distance migrating knots that winter in Argentina and Chile. However, the proposed rule presented less information regarding northbound or southbound passage of the knots that spend winter seasons in regions north of the Equator. One issue that needs elaboration is the relative numbers of knots that winter in each of these two large regions and the differences of habitat use and migration strategies that exist between them.

Our Response:
The proposed rule presented available data regarding numbers of red knots in each wintering area (Rufa Red Knot Ecology and Abundance pp. 38-45), summarized by Atkinson
et al.
(in Wader Study Group 2005) and Harrington
et al.
(2010b) regarding differences in migration strategy by wintering area (Rufa Red Knot Ecology and Abundance pp. 22, 32), and presented information regarding possibly greater reliance on HSC eggs by migrants from Argentina and Chile relative to birds from more northern wintering areas (Rufa Red Knot Ecology and Abundance pp. 31-33). In the Supplemental Document, we have added a section (Wintering—Northern Versus Southern) to summarize the differences between red knots from northern versus southern wintering areas that are discussed elsewhere in the document, moved and supplemented information to a new section (Migration—Differences in Migration

Strategy by Wintering Region) on differences in migration strategies, and clarified information regarding differential reliance on HSC eggs (Wintering and Migration Food).

(9) Comment:
The peer reviewer noted the proposed rule stated that red knots require stopovers rich in easily digested food to achieve adequate weight gain due to changes in the digestive system that birds undergo before long flights. This may be less true for the knots from northern wintering grounds.

Our Response:
In the proposed rule, we noted this possible physiological difference between southern- and northern-wintering rufa red knots (Rufa Red Knot Ecology and Abundance, pp. 30-31), but we did not mention this possible difference in the section cited by this commenter (Rufa Red Knot Ecology and Abundance, p. 17). In the Supplemental Document (Species Information—Migration—Migration Biology), we have added a sentence to this paragraph to clarify that some researchers have suggested that digestive system changes are more pronounced, or have a more pronounced effect on energy budgets at the stopover areas, in southern-wintering (Argentina and Chile) than in northern-wintering (Southeast United States) rufa red knots (Niles
et al.
2008, p. 36; Atkinson
et al.
2006b, p. 41). We have also added a cross reference in this paragraph to refer readers to a more detailed discussion of this issue that is presented under Migration and Wintering Food—Horseshoe Crab Eggs—Possible Differential Reliance on Horseshoe Crab Eggs.

(10) Comment:
The peer reviewer suggested the term “full segregation” is unclear with regard to migration strategies, routes, or stopover areas among red knots from different wintering areas. There is a good deal of segregation in stopover regimens and in molt regimens between southbound knots with destinations in Argentina and Chile versus northern-hemisphere wintering birds. There also appears to be some degree of difference in stopover habitat use between these two groups in northbound migration.

Our Response:
We have clarified the lack of full segregation by providing examples in the Supplemental Document (Migration—Differences in Migration Strategy by Wintering Area). Also see
Our Responses 8
and
9
above.

(11) Comment:
The peer reviewer stated northern- versus southern-wintering knots have different strategies in southward migration. The southern group has essentially passed through Atlantic regions of North America before September, and strongly depends upon being able to accumulate fat and protein prior to launching on over-ocean flights between North and South America. Northern-wintering birds, however, linger on the North American coast (
e.g.,
Massachusetts, Georgia coasts), are using “stopover” locations as molting areas, and are using different food and habitat resources as compared to the southern-wintering knots. The resource requirements by birds of these two groups during southward migration are quite different.

Our Response:
We have added this information with supporting citations to the new section of the Supplemental Document (Migration—Differences in Migration Strategy by Wintering Region).

(12) Comment:
The peer reviewer noted that, historically, oiling was perhaps an important problem to knots in Patagonia, and suggested limited information was available in the reference Harrington and Morrison 1980.

Our Response:
Some of the data from Harrington and Morrison (1980) were presented in the proposed rule (78 FR 60024, p. 60086) from a secondary source (Niles
et al.
2008, p. 98). We have added the rest of these data and this reference to the Supplemental Document (Factor E—Oil Spills and Leaks—South America).

(13) Comment:
The peer reviewer stated that, although the Costa del Este area of Panama City, Panama (referenced in the proposed rule, 78 FR 60024, p. 60043), is a very important location for many kinds of shorebirds, few knots have been reported from here.

Our Response:
We agree that only moderate numbers of
Calidris canutus
have been reported in most seasons from Panama's Pacific coast (which includes habitats near Panama City as well as other sites). However, larger numbers have been reported from Pacific Panama during fall migration. In the proposed rule (Rufa Red Knot Ecology and Abundance, pp. 41-42, 52), we presented available data regarding numbers of
C. canutus
in Panama. We have consolidated and updated these data with new information in the Supplemental Document (see Population Surveys and Estimates—Central America and Pacific South America).

(14) Comment:
The peer reviewer stated that recently published data show dramatic declines and shifting of stopover locations during south migration in Massachusetts.

Our Response:
This information (Harrington
et al.
2010a; Harrington
et al.
2010b) was presented in the proposed rule (Rufa Red Knot Ecology and Abundance, p. 51). We have expanded the discussion of these results in the Supplemental Document (Migration—Atlantic Coast—Fall Timing and Distribution; Population Surveys and Estimates—Fall Stopover Areas).

(15) Comment:
The peer reviewer stated that the proposed rule was incorrect in describing only small numbers of red knots on mid-Atlantic and northern Atlantic beaches between Memorial Day and Labor Day. Currently about 1,000 to 2,000 knots occur on the Massachusetts coast during the fall migration period, and numbers were previously much higher. Peak dates for these southbound migrants are in July and August.

Our Response:
This statement appeared in the section of the proposed rule addressing beach cleaning (78 FR 60045). We have revised the Supplemental Document (Population Surveys and Estimates—Fall Stopover Areas; Factor A—Beach Cleaning) to correct this information.

(16) Comment:
The peer reviewer stated that there has been a major shift of key stopover areas of knots in south migration in Massachusetts since the 1980s when up to 10,000 southern-wintering knots were heavily concentrated on the western shore of Cape Cod Bay (Harrington
et al.
2010a).

Our Response:
We discussed the findings of Harrington
et al.
(2010a) in the proposed rule (Rufa Red Knot Ecology and Abundance, p. 51). We have revised several sections of the Supplemental Document to provide more specific results from this study (Migration—Differences in Migration Strategy by Wintering Region; Historical Distribution and Abundance; Population Surveys and Estimates—Fall Stopover Areas).

(17) Comment:
The peer reviewer stated that the proposed rule (78 FR 60024, p. 60046) notes that more red knots were documented in northeast Brazil in the 2000s than during the early 1980s. The wording of this paragraph could be misconstrued to suggest that habitats were improved by the development from shrimp farm ponds.

Our Response:
We agree and have clarified this point in the Supplemental Document (Factor A—Agriculture and Aquaculture).

(18) Comment:
The peer reviewer commented that the proposed rule (78 FR 60024, p. 60045) stated that beach-cleaning machines are likely to cause disturbance to roosting and foraging red knots. This is more of an issue with respect to roosting than to foraging. In almost all cases, raked areas would be

beaches that knots might use during high tides for roosting (if not for high levels of human disturbance), but not as sites for foraging. Beach cleaning generally happens on beaches intensively used for human recreation. Because of heavy human use, knots that might otherwise roost in these areas would generally avoid such locations. Thus, the issue would be disturbance versus beach cleaning.

Our Response:
The proposed rule (78 FR 60024, p. 60077) noted that roosting red knots are particularly vulnerable to disturbance. We have revised the Supplemental Document to cross-reference this information under Factor A—Beach Cleaning, and to note in this same section that beach-cleaning typically occurs along or landward of the high tide line where red knots may roost but are unlikely to forage. The proposed rule (78 FR 60024, p. 60044) states that mechanical beach cleaning is most commonly conducted on beaches that are heavily used for tourism. We agree that disturbance to red knots from recreational activities may, on many beaches, be greater than the disturbance from the beach cleaning machines. However, beach cleaning may occur at times of day (
e.g.,
early morning, evening) when few recreational activities are taking place, thus increasing the total daily duration that knots are disturbed by human activities. Conversely, many raked beaches may have such high levels of human recreational use that red knots are precluded from using them entirely; in such cases there would be no incremental additional disturbance from the raking activities. We have added these conclusions to the Supplemental Document (Factor A—Beach Cleaning). In addition, the proposed rule already described (78 FR 60024, p. 60044) physical impacts to beach habitats from mechanical beach cleaning.

Federal Agency Comments

(19) Comment:
One Federal agency provided data regarding the seasonality and abundance of red knots in or near units managed by the NPS in the Central and Eastern United States. To assess gross trends in occurrence of red knots across NPS units, this commenter considered vetted eBird data points where birding effort was reported, and found that, in the NPS units where most red knot occurrences were reported (Assateague Island, Cape Lookout, Cape Hatteras, Cape Cod, Gateway National Recreation Area, and Timucuan Ecological and Historic Preserve), a clear declining trend in red knot observations was detected since 1980.

Our Response:
We thank the commenter and have added this trend information to the Supplemental Document (Population Surveys and Estimates). The information regarding the seasonality and abundance of red knots at individual NPS units will be valuable for purposes of recovery planning, management under section 7(a)(1) of the Act, and consultation under section 7(a)(2) of the Act.

(20) Comment:
One Federal agency noted that several Navy installations within the range of the red knot have Integrated Natural Resources Management Plans in place that benefit the red knot, including provisions for shoreline protection.

Our Response:
We appreciate this information and anticipate working closely with these installations as we develop a critical habitat designation, and develop and implement a recovery plan for the red knot.

(21) Comment:
One Federal agency commented that the proposed rule and supporting document overemphasized the risks to the red knot, and birds in general, associated with offshore wind energy development. In addition, several States and other commenters stated that wind energy development outside of coastal areas is unlikely to be a significant threat to red knots.

Our Response:
In both the proposed rule (78 FR 60024, pp. 60089-60093) and the Supplemental Document (Factor E—Wind Energy Development), we have summarized and characterized the best available data regarding risks to the red knot from both offshore and terrestrial wind energy development. We have made considerable revisions to this section of the Supplemental Document to reflect substantive public comments and new information (see also
Our Responses 62, 134
to
137
). We conclude that wind energy development, especially near the coasts, may cause some unquantifiable amount of red knot mortality into the foreseeable future, and that one model indicated this species is vulnerable to population-level effects from even low levels of anthropogenic mortality (Watts 2010, pp. 1, 39). Unless facilities are constructed at key stopover or wintering habitats, we do not expect wind energy development, especially offshore or inland, to cause significant direct habitat loss or degradation, or displacement of red knots from otherwise suitable habitats.

(22) Comment:
One Federal agency stated that, in addition to the total number and height of offshore turbines, exposure is a factor contributing to avian collision risks. For red knots, exposure to offshore wind facilities is reduced because (1) they can fly nonstop for 1,500 miles (mi) (2,414 kilometers (km)), which limits their time over the open ocean, and (2) birds on long-distance flights, such as red knots crossing the offshore environment, fly at higher altitudes than short-distant migrants.

Our Response:
We agree that exposure to wind turbines is a contributing factor to avian collision risk. The proposed rule (78 FR 60024, pp. 60090-60091) presented the findings of Burger
et al.
(2011, entire), who used a weight-of-evidence approach to examine the risks and hazards to red knots from offshore wind energy development on the OCS at three spatial levels of exposure. We concur that the red knot can fly nonstop for 1,500 mi (2,414 km) and that some knots have limited temporal exposure to the offshore environment (Normandeau Associates, Inc. 2011, p. 202). Geolocator data show certain knots crossing the OCS as many as six times per year, and because these numbers reflect only long flights, more crossings of the OCS may occur as birds make shorter flights between States (Burger
et al.
2012c, p. 374).

It is estimated that the normal cruising altitude of red knots during migration is between 3,281 to 9,843 feet (ft) (1,000 to 3,000 meters (m)) (Burger
et al.
2011, p. 346), well above the estimated height of even a 10-megawatt (MW) offshore turbine (681 ft; 207.5 m). However, lower flight altitudes may be expected when red knots encounter bad weather or high winds, and these lower flight altitudes are known to occur on ascent or descent from long-distance flights, during short-distance flights if they are blown off course, during short coastal migration flights, or during daily commuting flights (
e.g.,
between foraging and roosting habitats) (Burger
et al.
2012c, pp. 375-376; Burger
et al.
2011, p. 346), as discussed in the proposed rule (78 FR 60024, p. 60090).

(23) Comment:
One Federal agency stated that some studies and analyses used in the proposed rule (78 FR 60024) fail to distinguish between onshore/nearshore and offshore wind energy development. This distinction is important because the species at risk and the magnitude of the risk can be considerably different. The agency further stated that coastal environments generally have higher concentrations of birds than offshore areas and that birds taking off from land may fly through the rotor zone before reaching cruising elevation. In addition, this commenter questioned our conclusions about the risk of bird collisions with offshore wind facilities, which were based on a

scientific paper (Kuvlesky
et al.
2007) summarizing research from Europe.

Our Response:
In the proposed rule (78 FR 60024, p. 60089-60092), we addressed separately land-based wind energy development (including along the coasts) versus in the offshore environment. Based on the high frequency and lower altitudes of red knot flights along the coast (
e.g.,
ascent or descent from long-distance flights, during short coastal migration flights, or during daily commuting flights between foraging and roosting habitats) (D. Newstead pers. comm. March 5, 2013; Burger
et al.
2012c, pp. 375-376; Burger
et al.
2011, p. 346; Stewart
et al.
2007, p. 1; Alerstam
et al.
1990, p. 201), we agree with the commenter that collision risk per turbine (notwithstanding differences such as size, design, operation, local habitats) along the coasts (both on land and nearshore) is likely higher than in areas either far offshore or far inland. We have revised the Supplemental Document (Factor E—Wind Energy Development—Terrestrial) to reflect this conclusion. We have also revised the Supplemental Document (Factor E—Wind Energy Development) to move the discussion of avian collision risk factors (
e.g.,
weather, light levels, lighting, turbine characteristics, habitats) and displacement effects to be generalized across both terrestrial and offshore wind energy facilities, as the citations supporting this discussion pertain to both.

In the proposed rule (78 FR 60024, pp. 60089-60091), we did not attempt to differentiate between nearshore (
e.g.,
State waters) and the OCS. Although we still have little information on avian impacts from turbines far offshore, we have updated our conclusions in the Supplemental Document (Factor E—Wind Energy Development—Offshore) to reflect geolocator results by Burger
et al.
(2012c, p. 373) and analysis by Burger
et al.
(2011, p. 346) suggesting red knot collision risk may decrease far offshore. Finally, we have removed the following statement from the Supplemental Document (Factor E—Wind Energy Development—Offshore): “Research from Europe, where several offshore wind facilities are in operation, suggests that bird collision rates with offshore turbines may be higher than for turbines on land.” Upon further review of the source cited for this statement (Kuvlesky
et al.
2007, p. 2489), we found that these authors presented results from both coastal and nearshore wind facilities. Further, these authors went on to present countervailing findings from other studies, and did not cite any studies from wind turbines located far offshore. Therefore, we reasoned that this statement from the Kuvlesky
et al.
2007 paper was not appropriate to include in this final rule.

(24) Comment:
One Federal agency commented that the Bureau of Ocean Energy Management (BOEM) has worked with State Task Forces to determine the best locations for wind energy development to help avoid impacts. For example, areas being considered are greater than 9 mi (14 km) offshore; the Virginia lease area is 23.5 nautical miles (nm) (43.5 km) from Virginia Beach.

Our Response:
We concur that siting far offshore may succeed in reducing overall avian collision hazards, including for red knots, although species that rely on the offshore environment for breeding, feeding, or sheltering (
e.g.,
certain seabirds and waterfowl) may have increased exposure risk to turbines farther offshore. We appreciate the work of BOEM to evaluate and minimize avian collision risks in siting decisions, and this information has been added to the Supplement Document (Factor E—Wind Energy Development—Offshore). However, we also updated this section of the Supplemental Document to compare these distances offshore with red knot use areas delineated by Burger
et al.
(2012c, p. 373) based on geolocator results, which do appear to have some overlap with both the offshore commercial wind energy development leases executed to date and the Wind Energy Areas (WEA) where BOEM will focus for future leases, including areas off the mouth of Delaware Bay (BOEM undated, p. 1).

(25) Comment:
One Federal agency stated that BOEM recently published a study on the relative vulnerability of migratory bird species to offshore wind energy projects on the Atlantic OCS; the study ranked the relative vulnerability of 177 migratory bird species to collision and displacement by offshore wind turbines. The relative collision vulnerability of red knot was “medium” and the relative vulnerability to displacement “low.”

Our Response:
We have reviewed this report and incorporated the findings into the Supplemental Document (Factor E—Wind Energy Development—Offshore). We note that some of the factors considered in this report are not specific to the
rufa
subspecies of
Calidris canutus,
and thus the numerical vulnerability scores are not applicable to
rufa.

Comments From States

(26) Comment:
One State expressed disappointment in the Service's communication regarding the proposed rule. Because of the wide geographic scope of this listing proposal, the Service should have engaged all of the State wildlife agencies for their input prior to publication and should have briefed the State agency directors about the proposed expansion of the rufa red knot's listed range. In addition, several States and other commenters stated that the proposed rule contained inadequate justification for a sweeping change in the red knot's range from previous Service documents (
e.g.,
2006 to 2011 Candidate Notices of Review (CNORs)).

Our Response:
We regret that this State is disappointed in our communication efforts on the rufa red knot proposed listing. We acknowledge the proposed range was greatly expanded from what was described in the last CNOR update, but the proposed rule (78 FR 60024) and this final rule contain our analysis of, and conclusions drawn from, the best scientific and commercial data available. Substantial new data have become available since 2011, the last year we were required to update the knot's CNOR form. We also acknowledge that the 2011 CNOR form indicates the rufa red knot's range is limited to coastal areas and did not include interior portions of the coastal States or any inland States. The 2011 CNOR was based on the best data available at the time. Our understanding of the species' biology and occurrence records evolved rapidly based on results from geolocator research followed by enhanced analysis of national and regional databases. The proposed rule (Rufa Red Knot Ecology and Abundance, pp. 21, 23) explained the best available data and supported the expanded geographic scope of analysis under the Act. The discussion of these data has been updated and expanded in the Supplemental Document (Species Nonbreeding Distributions; Migration—Midcontinent; Migration and Wintering Habitat—Inland; Population Surveys and Estimates—Inland Areas Spring and Fall). We will strive to improve our communication with the States as we greatly value our conservation partnerships.

(27) Comment:
Several States and other commenters stated that the proposed rule is generally lacking in scientific evidence and is based on speculative information. For example, (1) in the proposed rule, the Service repeatedly made undocumented claims and speculated that a variety of items “may” be a factor that could cause the demise of the species; (2) in describing threats and risks to the red knot, the proposed rule used terms such as high uncertainty, expected, likely, may, could, possibly, and unknown but

possible; (3) although the best available science has been used to generate predictions about some possible future impacts, best available science has not been used to examine and explain the relevance of potential threats (
e.g.,
sea level rise, climate change) to recent red knot population trends; (4) because of the potentially serious ramifications of a Federal listing on Federal programs and permitting processes, it is neither sufficient nor professional to base listing decisions so heavily upon speculation; and (5) the principle of best available science must be used to demonstrate causal relationships between threats and population change. In a related comment, one commenter stated that it is well-established that the Act does not provide for the listing of species on the basis of speculative, uncertain, or inconclusive information. A number of courts (
i.e., Conner
v.
Burford, Trout Unlimited
v.
Lohn, Ctr. for Biological Diversity
v.
Lubchenco, Bennett
v.
Spear,
and
Nat'l Res. Council
v.
Daley
) have determined that the threshold decision to list a species as threatened or endangered is not to be based on speculation or a misplaced intent to err on the side of species conservation. The default position for all species is that they are not protected under the Act.

Our Response:
We disagree that our analysis is “speculative.” The Service is required to make listing determinations based on the best scientific and commercial data available. Sources of data include peer-reviewed journal articles; field notes and other unpublished data; and personal communications with species, habitat, and policy experts. We analyze these sources of data and use our best professional judgment to determine their credibility, in accordance with applicable data standards (Interagency Policy on Information Standards Under the Endangered Species Act (59 FR 34271); Information Quality Act (P.L. 106-554, section 515); Information Quality Guidelines and Peer Review (USFWS 2012f, entire). All data have some level of uncertainty, but the proposed rule properly identified, through citations, the data sources and was transparent in qualifying areas and levels of uncertainty.

In making a listing determination, we evaluate the threats affecting a species in the past, currently, and into the foreseeable future. What constitutes the foreseeable future may be different for each threat, given our confidence in the sources of the data and their level of certainty regarding future conditions. The proposed rule and Supplemental Document discuss what information we can reliably use to reasonably foresee into the future. As discussed below, the Act and our policies do not require a definitive knowledge of what will happen in the future, only what we may reasonably predict is likely to occur. Although there is some inherent uncertainty surrounding the threats we evaluated for the red knot, this does not prevent us from making a credible assessment of the likely direction and magnitude of those impacts, even though it may not be possible to make such predictions with precision. In addition, the proposed rule and its underlying data were available for peer review and extensive public review and comment, but the commenters did not provide additional substantive information to refute our analysis or assumptions.

Under section 4 of the Act, a species shall be listed if it meets the definition of threatened or endangered because of any (one or more) of the five factors that are a basis for making a listing determination, considering solely best available scientific and commercial data. Although many species proposed for listing have undergone, or are undergoing, a population decline, declining numbers (rangewide or in portions of the range) are not necessary for listing if a species is facing sufficient threats, now or in the foreseeable future, to meet the definition of threatened or endangered. Accordingly, not all threats contributing to a species' threatened or endangered status must be tied to past or ongoing population declines; threats for which the species is listed may not be affecting the species at the time it is being evaluated for listing, but are likely to do so in the future.

The commenter is incorrect in asserting that “the default position for all species is that they are not protected under the Act,” or that listings must be based on conclusive evidence. As stated above, the Act and our policies do not require a definitive knowledge of what will happen in the future, only what we may reasonably predict is likely to occur when making a listing determination.

Further, our decisions are not based on speculation or misplaced intentions. The Act requires the Service to base its listing determination on the “best scientific and commercial data available” (16 U.S.C. 1533(b)(1)(A)). The “best available science” requirement does not equate to the best possible science. Instead, this information standard simply prohibits the Service from disregarding available scientific evidence that is better than the evidence it initially relied upon. The Service is required to rely upon the best available science, even if that science is uncertain or even “quite inconclusive” (
i.e., Trout Unlimited
v.
Lohn,
645 F. Supp. 2d 929, 947 (D. Or. 2007) (“
Trout Unlimited”
);
Southwest Center for Biological Diversity
v.
Babbitt,
215 F.3d 58, 60, 342 U.S. App. D.C. 58 (D.C. Cir. 2000)). The case law cited by the commenters supports this position.

In distinguishing endangered from threatened, Congress defined “threatened” species as a species that is “
likely
to become an endangered species within the foreseeable future throughout all or a significant portion of its range” (16 U.S.C. 1532(20)) (emphasis added). Courts have acknowledged the word “likely” clearly means something less than 100 percent certain (
Trout Unlimited
at 947). Moreover, courts have found that an agency is entitled to particular deference where it has drawn conclusions from scientific data (
i.e., Marsh
v.
Or. Natural Res. Council,
490 U.S. 360, 375-77 (1989);
Ethyl Corp.
v.
EPA,
541 F.2d 1, 36 (D.C. Cir. 1976);
Oceana
v.
Evans,
384 F. Supp. 2d 203, 219 (D.D.C. 2005) (citing cases)).

(28) Comment:
Several States and other commenters stated that the rufa red knot geographic range should include only areas where the species occurs regularly (annually or near annually), and should avoid identifying jurisdictions (
e.g.,
States) merely because they represent continuous geographies between discrete regularly used stopover sites. As presented in the proposed rule, the red knot range is inconsistent with how the Service has defined the range of other listed migratory birds. These commenters also noted that although eBird is a useful resource, the Service should not have used it as the sole source for determining the species' range in a listing process, and suggested a more thorough and comprehensive review of occurrence records should be conducted.

Our Response:
In both the proposed and final rules, we have defined the rufa red knot's range based on the best available data; however, we recognize that scientific understanding of this species' range will likely continue to improve over time. The Service may define a species' range using State boundaries or other geographically appropriate scale. How range is defined depends on characteristics of the species' biology and how it is listed (
i.e.,
as species/subspecies or a distinct population segment (DPS)). A species' or subspecies' range is typically described at the state or country scale. While the range of a DPS listing can include entire States, it is more typically defined at a more refined geographic scale because we must define where the discrete entity occurs.

We defined the rufa red knot's range based on the data from reliable published scientific literature, submitted manuscripts, and species' experts; occurrence data; and analysis (
e.g.,
estimated flight paths based on known wintering and breeding grounds combined with siting records). The regulations at 50 CFR 17.11(e) state, the “historic range” indicates the known general distribution of the species or subspecies as reported in the scientific literature. The present distribution may be greatly reduced from this historic range. This column [in the table at 50 CFR 17.11(h)] does not imply any limitations on the application of the prohibitions in the Act or implementing rules. Such prohibitions apply to all individuals of the species,
wherever found
[emphasis added]. Therefore, whether a specific State or geographic area is included or excluded from the textual description of the rufa red knot's range, the subspecies would be protected under the Act wherever it may be found, for as long as it remains federally listed. (See also
Our Response 33
below.) Although a species is listed wherever found, we strive to accurately describe the range in the 50 CFR 17.11 table based on the best available data at the time of listing. For earlier listed species such as the piping plover and Kirtland's warbler, certain tools to help us understand the migration routes of birds (
e.g.,
satellite transmitters, geolocators, eBird) were not available at the time.

See
Our Response 82
for explanation of how we have interpreted and utilized eBird data. We did not solely rely on eBird data to determine the rufa red knot's range. In addition to eBird, we also relied heavily on Newstead
et al.
2013 (draft manuscript we had at the time) and Morrison and Harrington 1992, and to a lesser degree on Skagen
et al.
1999. These four sources constituted the best available data at the time. For this final rule, we have also considered an analysis for the Mississippi Flyway done by our Midwest Region Migratory Bird Program (Russell 2014), the State reports provided by the Central Flyway Council and other commenters, updated versions of Newstead
et al.
(2013) and Carmona
et al.
(2013), and all other relevant new information we have received since March 2013 when we completed drafting of the proposed rule. These new sources further validate our assumptions and conclusions outlined in the proposed rule. See
Our Response 35,
below, and the Supplemental Document (Subspecies Nonbreeding Distribution) regarding how we have delineated the nonbreeding ranges of
C.c. rufa
versus
C.c. roselaari
based on the best available data.

(29) Comment:
Several commenters, including States, stated that they were unaware of any reliably used stopover sites for the red knot in the interior portion of the United States. These commenters contended that bird occurrence data do not support the existence of stopover sites (defined as habitats or locations that consistently provide migrants with the opportunity to refuel and rest) within the Central Flyway States, and that observed behavior and diet reinforce the concept that red knots do not regularly use and do not require any inland wetland locations as stopover sites within the interior of the Central Flyway. Further, most interior records are for vagrant, single birds, and interior sightings are so sparse that they are ecologically insignificant. These State commenters specifically requested removal of their particular States from the range, and requested that listing of the rufa red knot not confer any requirements for any Federal or State agency or private landowner. Conversely, one commenter rebutted that, as is frequently the case for “jump” migrants, periodic weather events or other circumstances occasionally result in birds being grounded in locations or habitats that are only infrequently used along the flyway. This commenter also stated that while this may be the case for some of the interior areas, recent communications with biologists working in North Dakota indicate that habitats in this region (
e.g.,
Missouri River sandbars) are far more regularly used than eBird records or other databases would indicate. Further, additional unpublished geolocator tracks also show use of sites throughout the Missouri Coteau, on both U.S. and Canadian sides of the border, as spring migration stopovers. This commenter stated that the Service should make a more complete assessment of the occurrence of the species in North Dakota, and possibly other States, by contacting other biologists that may have additional information that is not captured in electronic databases.

Our Response:
We also are unaware of any consistently used rufa red knot stopover sites in the U.S. portion of the Central Flyway. However, all three of our primary sources (Newstead
et al.
2013, Skagen
et al.
1999, and eBird.org 2014) suggest that habitats in the plains of southern Canada (Alberta, Saskatchewan, Manitoba) are routinely relied upon by migrating knots at least under certain conditions (
e.g.,
favorable water levels). In addition, from the relatively small sample size in Newstead
et al.
(2013, p. 56), one of six birds used North Dakota for 14 days in spring. We do not yet know how aberrant or representative this bird was, but these results indicate the possibility that the documented Northern Plains stopover region may be found to extend into the United States, as research on midcontinental migrants continues. This possibility is supported by the new geolocator information regarding additional knots on the U.S. side of the Missouri Coteau (D. Newstead pers. comm. May 8, 2014), including three in northern North Dakota, two in northern Montana, and one possibly further south (
e.g.,
Nebraska) (D. Newstead pers. comm. May 16, 2014). Newstead
et al.
(2013, p. 56) found that the Northern Plains were used as a northbound stopover by five of six birds in 2010 (including the one in North Dakota), with the sixth bird using Hudson Bay. Hudson Bay was used by three of three birds in 2011. Although the sample size (
e.g.,
recovered geolocators) is small, a large proportion of the recovered geolocators show red knots using a midcontinental flyway. Therefore, these results suggest that, in years when conditions favor it, a large proportion of midcontinental migrants may use Northern Plains stopovers in spring. In addition, birds using the Northern Plains as a spring stopover stayed an average of 16.2 days (Newstead
et al.
2013, Table 3); this was not a short stop but actually similar to the stopover duration in Delaware Bay.

In the proposed rule, we did not define “stopover site.” In the Supplemental Document (Migration—Stopover Areas), we have added clarification that places where migrant birds stop to rest, drink, and eat are often described as either stopover or staging sites, with the two terms frequently used interchangeably (Warnock 2010, p. 621). We have adopted the definitions of Warnock (2010, p. 621) that all sites where migrants rest and feed are stopover sites, while staging sites are a subset of stopovers that provide abundant and predictable food resources without which birds would incur significant fitness costs.

We agree that many of the inland red knot sightings to date represent single birds. However, we understand the term “vagrant” to mean a bird that has strayed or been blown far from its usual range or migratory route; synonymous with “accidental.” According to Russell (2014, p. 1), “accidental” implies an extraordinary record, out of the normal pattern, and unlikely to occur again. Based on this understanding of the term,

we disagree with characterizing rufa red knots in the Central Flyway as vagrant, based on geolocator results showing that the midcontinent does constitute the most prevalent migratory route for at least some birds that winter in Texas (D. Newstead pers. comm. May 8, 2014; Newstead
et al.
2013, entire). Based on these geolocator data, we conclude that a substantial proportion of Texas-wintering knots pass over the Central Flyway twice annually during migration. Other than the Northern Plains of southern Saskatchewan (and potentially extending into the northern U.S. plains), we are not currently aware of any other stopover sites in the Central Flyway that are routinely or intermittently relied upon by a substantial number of birds.

Further, there are clusters of sightings records in both the midcontinent and further east through the Mississippi Valley and along the Great Lakes. These cluster areas warrant further study to more fully evaluate their usage as red knot stopovers. (See Supplemental Document section Migration—Midcontinent—Stopovers.) As recommended by one commenter, we anticipate a more complete assessment of unpublished or anecdotal sightings data in the course of recovery planning. The existence of such additional sightings data, and the geographic clustering of the eBird data along water bodies, suggest that some inland areas may, upon further study, be found to routinely or intermittently support roosting and feeding red knots during migration.

(30) Comment:
Several States and other commenters noted Newstead
et al.'s
(2013) findings that more than 10,000 red knots from the Atlantic coast have been uniquely marked. These commenters highlighted the authors' conclusion that “The paucity of resightings in Texas suggests that most of these knots probably do not share the same wintering or stopover sites as those associated with the West Atlantic flyway.”

Our Response:
We agree that available data do not show any use of a midcontinental (inland Texas through North Dakota) flyway by knots known to winter or stopover along the U.S. Atlantic coast. However, Newstead
et al.
2013 go on to say, “The paucity of resightings in Texas suggests that most of these knots probably do not share the same wintering or stopover sites as those associated with the West Atlantic flyway,
though the paucity may be the result of limited effort and/or reporting
” [emphasis added]. Indeed, we have updated the Supplemental Document with new geolocator data confirming earlier indications (from resightings) that at least some Texas-wintering knots do mix with Atlantic coast birds during migration, both in Canada (Migration—Midcontinent—Spring) and the United States (Migration—Midcontinent—Flyway Fidelity).

(31) Comment:
Several States and other commenters stated that records of this species' occurrence in the midcontinent suggest red knots use a “jump” migration strategy, whereby birds fly over the Southern and Central Great Plains and stopover at sites in the Northern Great Plains, principally in Southern Canada. Further, both spring and fall migrations involve a single 2- or 3-day flight between the Gulf coast and Canada.

Our Response:
We agree that this picture of midcontinent migration (long “jumps” mainly to Southern Canada) is consistent with best available data. However, that body of available data (mainly Newstead
et al.
2013, Skagen
et al.
1999, and eBird.org 2014) is not extensive. Newstead
et al.
(2013) did find 2- or 3-day migration flights between Texas and the northern stopovers, based on a sample size of eight geolocators, some of which had been carried by the same birds for 2 full years. In addition to Newstead's research, our review of reliable national and regional occurrence data (Central Flyway Council 2013; eBird 2012; A. Simnor pers. comm. October 15, 2012) found multiple rufa red knot sighting records in every interior State. See
Our Response 29
for discussion of potential stopover areas in the interior United States.

(32) Comment:
Several States and other commenters stated that a separate population of rufa red knots exists in the midcontinent of the United States and this population may constitute a DPS; therefore, a DPS analysis should be conducted. Further, these commenters stated that there is no compelling evidence that the midcontinental population meets the definition of threatened and none of the threats affecting the Atlantic coast population are applicable to the midcontinental population.

Our Response:
Under the Act, we may list a species, subspecies, or a DPS of a vertebrate species. The Act's definition of “species” includes “any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreed when mature.” We have no evidence that the rufa red knot is composed of separate populations that may warrant protection of the Act at less than the subspecies level. Based on the best scientific and commercial data available, we determined the
rufa
subspecies of the red knot to warrant listing as threatened throughout its entire range.

(33) Comment:
Several States and other commenters stated that giving infrequently or unused areas the same standing as regularly used and critically important sites ultimately hinders conservation efforts and is counterproductive. Listing in the Central Flyway States will result in expenditure of resources and create unnecessary bureaucracy (
e.g.,
to conduct consultations) in areas with little to no occupancy, potentially diverting resources away from coastal habitats where they would have substantially greater conservation benefit. Further, listing in the Central Flyway States has no conceivable conservation benefit to red knots or to noncoastal wetland habitats, which already derive protection from other listed species like the piping plover, whooping crane, and interior least tern.

Our Response:
We disagree. The Service must make its determination on whether a species, subspecies, or DPS meets the definition of threatened or endangered based solely on the best available scientific and commercial data. This determination is based only on an analysis of the population and threats affecting the species as set forth under sections 4(a) and 4(b) of the Act. The extent to which a potential listing will or will not advance the conservation of any particular ecosystem (
e.g.,
noncoastal wetlands) is not a factor we may consider when determining whether a species meets the definition of threatened or endangered, nor may we consider economic information, including workload implications. As discussed above in
Our Response 28,
the provisions of the Act apply to all individuals of a listed species
wherever found
(emphasis added). Upon listing, therefore, the rufa red knot is protected by the Act wherever it occurs, even as scientific understanding of its range will likely continue to improve over time. That said, the Service has the appropriate tools under sections 7 and 10 of the Act to work with our State, Federal, and private partners to appropriately evaluate the likelihood of effects to red knots stemming from proposed activities. Such evaluations will be based on the species' level of exposure to the proposed activity, including the frequency and consistency of the species' occurrence in the affected area, and the type of activity, including its timing and duration. These evaluations may be done at different geographic scales.

During the recovery planning process we will focus on those stopover sites, both coastal and inland, that support the largest concentrations of birds, based on best available data. Inland habitats could be an important feature for certain flyways at certain times (
e.g.,
during particular weather conditions). Based on best available information, the Texas-wintering birds using the Central Flyway are important to the red knot's overall conservation because these birds contribute to the subspecies' resiliency and geographic representation. Protecting these birds and their habitats under the Act does have conservation benefit to the rufa red knot.

(34) Comment:
One State commented that, given the longitudinal relationship between the Atlantic coast of the United States and the Pacific coast of South America, as well as the documented occurrence of marked
Calidris canutus rufa
in Panama and the central coast of Chile (González
et al.
2006), it is conceivable that some
C.c. rufa
winter in sympatry (
e.g.,
occur in the same area) with
C.c. roselaari
along the Pacific coasts of Peru and Chile. Further, the subspecific affiliation of the knots that winter along the Pacific coast from southern Mexico through Chile is currently uncertain (78 FR 60024, p. 60026).

Our Response:
We agree. We have updated the Supplemental Document (Subspecies Nonbreeding Distributions) with considerable new information and new conclusions regarding the nonbreeding distributions of the
rufa
and
roselaari
subspecies, including areas of likely or potential overlap.

(35) Comment:
Several States and other commenters noted that the proposed rule includes inland States with low
Calidris canutus
occurrence (
e.g.,
Nebraska) while excluding other inland States with more numerous
C. canutus
occurrence records (
e.g.,
Utah). Despite past uncertainty,
C.c. roselaari
is now believed to be restricted to the Pacific coast based on current information.

Our Response:
Numerical prevalence of
Calidris canutus
does not shed light on which subspecies (
C.c. roselarri
or
C.c. rufa
) predominate in any particular area. There is considerable uncertainty regarding the subspecific identity of
C. canutus
in the western interior United States, and it is possible that the two subspecies both occur in this area during migration. This uncertainty was reflected in questions 5 and 10 under “Information Requested” in the proposed rule (78 FR 60025). Despite a number of population-wide morphological differences (USFWS 2011a, p. 305), the
rufa
and
roselaari
subspecies cannot be distinguished in the field because physical variability among individuals results in overlaps in many physical parameters (
e.g.,
wing and bill length) between the two subspecies (USFWS 2011a, p. 205; Harrington 2001, pp. 4-5; Harrington
et al.
1988, p. 441). Because these two subspecies cannot be distinguished in the field, other methods (
e.g.,
mark-resighting efforts, stable isotope analysis, genetics) are needed to delineate their distributions (D. Newstead pers. comm. September 14, 2012).

As discussed under
Our Response 28
and detailed in the Supplemental Document (Subspecies Nonbreeding Distributions—Western Interior United States), we defined the rufa red knot's Western U.S. range based on best available data from reliable published scientific literature, submitted manuscripts, and species' experts; occurrence data; and analysis (
e.g.,
estimated flight paths based on known wintering and breeding grounds combined with siting records). While it is possible that rufa red knots range nearly all the way to the Pacific coast during migration, we do not have any evidence to date (
e.g.,
genetics, mark-resightings, geolocator data, or stable isotope data) of
rufa
west of the Great Plains. We acknowledge considerable uncertainty around the subspecies composition in the Western States but conclude, based on best available data, that the
rufa
range likely extends to the western limit of the Great Plains (as mapped by the Level I ecoregions (U.S. Environmental Protection Agency (USEPA) 2013a)). See also
Our Response
82 below.

(36) Comment:
One State and several other commenters stated that, prior to a listing determination, more information is needed regarding the status and characteristics of red knot populations (
e.g.,
population status in Texas, connectivity of migratory flyways). In addition, gathering more scientific research on the red knot population in Texas will improve viability assessments of the entire subspecies throughout its range.

Our Response:
The proposed rule presented best available data regarding red knot population size, diet, habitat use, and threats in Texas, as well as the prevalence and migration patterns of
Calidris canutus rufa
versus
C.c. roselaari
in Texas (Rufa Red Knot Ecology and Abundance pp. 5-7, 9, 14-16, 21-24, 27, 34-35, 42; Factor D pp. 10-11; 78 FR 60024, pp. 60030, 60033, 60035, 60039-60042, 60044-60045, 60052, 60056, 60059, 60063, 60078, 60081, 60085-60086, 60089, 60092). Section 4 of the Act directs that listing determinations be made on the basis of the best scientific and commercial data available. We evaluated approximately 1,400 references during the preparation of the proposed rule, and communicated with numerous species and threats experts, to comply with this data standard required by the Act. We solicited peer review on the proposed rule. Peer review comments are reflected in the Supplemental Document, which has also been updated with new data regarding Texas, the nonbreeding distribution of rufa red knots, and connectivity of the flyways (Subspecies Nonbreeding Distributions; Migration; Migration and Wintering Habitat) that has subsequently become available through the public comment period and clarification from experts. Although a more complete picture of red knot ecology in Texas will be helpful for recovery planning, research to generate these new data is not yet available. As discussed in
Our Response 27
above, the “best available science” requirement does not equate to the best possible science. We acknowledge certain data gaps (78 FR 60024, pp. 60024-60025) and uncertainties, some of which are inherent in all natural systems and all evaluations of future conditions; however, we conclude that the best available data are sufficient to document several population-level threats to the red knot, as well as its reduced population size relative to the early 1980s, and thus conclude that the red knot meets the definition of a threatened species.

(37) Comment:
One State commented that the proposed rule did not provide comprehensive population numbers for either the historical or current population size for this subspecies or estimates that encompass the entire wintering range, the entire nesting range, or all of the potential migration stopover habitats along the U.S. Atlantic coast. This commenter believes the proposal gave undue importance to population trends at only two locations, Delaware Bay and Tierra del Fuego, and that maximum percent declines at these two sites are not sufficient for an evaluation of the severity of the apparent [rangewide] population decline. Further, because the red knot is highly mobile and individual birds and flocks appear to be capable of using different locations as stopover points from year to year, a more rigorous approach than subsampling should be used to assess population changes. Another commenter believes 40 years of data are not enough to show a trend in red knot populations and the Service

should look at hundreds of years of data.

Our Response:
As discussed in the Supplemental Document (Population Surveys and Estimates), we conclude that we do not have sufficient reliable data on which to base a precise rangewide population estimate. Thus, we have instead considered the best available data, which consists of survey data for specific regions. In the proposed rule, we limited our conclusions to trends within each regional data set (Rufa Red Knot Ecology and Abundance, pp. 53-54), though we did note a temporal correlation between declines at Tierra del Fuego and Delaware Bay (Rufa Red Knot Ecology and Abundance, p. 48). Although we lack sufficiently robust data to conclude if other wintering and stopover areas also declined, we conclude it is likely that declines at Tierra del Fuego and Delaware Bay drove an overall population decline (
i.e.,
lower total numbers), because these two sites are believed to have supported a large majority of rangewide knots (see
Our Response 38
). We note that our calculation of those regional declines (75 percent at Tierra del Fuego and 70 percent at Delaware Bay) are based on averages of early and late time periods, calculated to smooth out inherent variability in the data. In contrast, the maximum declines (
i.e.,
comparing only the single lowest count with the single highest count) were both recorded in 2011 and show an 81 percent decline at Tierra del Fuego and an 87 percent decline at Delaware Bay. Despite the above-mentioned limitations in producing a rangewide population estimate, we do note that several analyses conducted by others all concluded red knot numbers declined, probably sharply, in recent decades. While we did not rely on these other analyses, we do note that they are independently consistent with the conclusions we draw from the available (regional) data sets.

A more rigorous survey regime to estimate rangewide population changes over time may become available in the future. For example, mathematical population size estimates based on marked birds were begun in 2011 in Delaware Bay (J. Lyons pers. comm. September 3, 2013) and Georgia (GDNR 2013). This new method does not yet allow for trend analysis because only a few data points are available, and does not yet have the geographic coverage to permit a rangewide population estimate. However, the Act requires that we make listing determinations based on the best available data. The proposed rule identifies and evaluates the best available population information, which is associated with high confidence in those regions with long time series and consistent survey methods (
e.g.,
Delaware Bay, Virginia, Tierra del Fuego).

We disagree that these best available data cover an insufficient time period for trend analysis. Even with inherent annual variability, we conclude the available data are sufficient to document a sharp and prolonged period of decline in red knot counts in Delaware Bay and Tierra del Fuego in the 2000s. Further, we have gathered best available historical data dating back to the mid-1800s, as presented in the proposed rule (Rufa Red Knot Ecology and Abundance) and the Supplemental Document (Historical Distribution and Abundance, pp. 33-36). Although these historical data do not permit a quantitative analysis, they do convey a consistent qualitative account of historical declines and followed by, at least, a partial recovery.

(38) Comment:
One State questioned the validity of applying the observed decline in Delaware Bay to the entire population since, despite its apparent importance, the bay represents only a small portion of the Atlantic coast and the potential stopover habitat available to migrating red knots.

Our Response:
While, geographically, Delaware Bay represents only a small proportion of the total U.S. Atlantic coast, we conclude the bay supports a significant proportion of the total rufa red knot population during spring migration (Brown
et al.
2001, p. 10), as discussed in the proposed rule (Rufa Red Knot Ecology and Abundance, p. 29). Although no current, reliable, rangewide population estimate is available, reliable regional population data are available (see
Our Response 77;
Rufa Red Knot Ecology and Abundance, pp. 38-52; and Population Surveys and Estimates in the Supplemental Document). We have analyzed the most recent estimates of red knot numbers from each wintering region, Delaware Bay peak counts from the past 10 years, and Delaware Bay total passage population estimates from the past 3 years. Based on this analysis, we conclude that Delaware Bay continues to support the majority of red knots during spring.

That said, we agree that extrapolation of population declines in Delaware Bay to the rest of the red knot population should be conservative and undertaken only when supported by corroborating data. In the proposed rule, we presented data for specific regions (Rufa Red Knot Ecology and Abundance, pp. 38-52) and limited our conclusions to trends within each regional data set (Rufa Red Knot Ecology and Abundance, pp. 53-54). However, we also stated, “the pattern and timing of these declines in Delaware Bay relative to Tierra del Fuego and other stopovers is suggestive of a decrease in the overall population” (Rufa Red Knot Ecology and Abundance, p. 48). We agree that this statement was imprecise and have revised the Supplemental Document (Population Surveys and Estimates—Spring Stopover Areas—Delaware Bay) to clarify our conclusions drawn from best available data. We have also revised the Supplemental Document (Summary—Population Surveys and Estimates) to clarify, “Although we lack sufficiently robust data to conclude if other wintering and stopover areas also declined, we conclude it is likely that declines at Tierra del Fuego and Delaware Bay drove an overall population decline (
i.e.,
lower total numbers), because these two sites supported a large majority of rangewide knots during the baseline 1980s period.”

(39) Comment:
One State commented that the annual variation in the Delaware Bay peak counts suggests that knots are capable of altering their stopover behavior between years. It is unlikely that the actual population fluctuates at the high magnitude reflected in the Delaware Bay peak counts; therefore, year-to-year changes are probably related to variations in passage rates for birds moving through the region and variations in the use of multiple stopover sites.

Our Response:
We agree that the Delaware Bay peak counts are highly variable, but conclude that much of the short-term (year-to-year) variation can be attributed to the fact that peak counts are only a proxy measure for the total passage population. Year-to-year differences in the month-long patterns of arrival and departure would affect the percentage of total passage population that is captured by each year's peak count (
e.g.,
some years more birds may depart early and be missed by the late-May peak count). It is also possible that the survey date has missed the true peak number of birds in some years, particularly after 2008 when weekly, season-long survey efforts were scaled back to focus only on the end of May. That said, we also agree that red knots may switch between mid-Atlantic stopovers between, and even within, years, and that this flexibility may explain part of the variability in the data from both Delaware Bay and Virginia (Supplemental Document tables 8 and 11). We noted this flexibility in spring stopovers in the proposed rule (Rufa Red Knot Ecology and Abundance, p.

20). Despite the high variability, we attach high confidence to the long-term trend evident in the Delaware Bay peak count data, based on the consistent methods and observers, particularly during the core years of 1986 to 2008.

(40) Comment:
One State and several other commenters stated that recent population estimates calculated from resightings of banded knots using capture-recapture statistical methods should not be conflated with long-term data sets of maximum 1-day (peak) counts.

Our Response:
The proposed rule (Rufa Red Knot Ecology and Abundance, pp. 47-51) did not conflate population estimates derived from these two different methods. As we explain in the Supplemental Document (Population Surveys and Estimates—Spring Stopover Areas), because birds pass in and out of a stopover area, the peak count (the highest number of birds seen on a single day) for a particular year is lower than the total passage population (
i.e.,
the total number of birds that stopped at that site over the course of that migration season). For this reason, we have not compared data sets estimating total passage population (from capture-recapture statistical methods) with those of peak counts (maximum 1-day counts). We present these data sets separately in tables 9 to 13 of the Supplemental Document, with data updates where available.

(41) Comment:
One State concluded that peak red knot numbers in Delaware Bay have been stable to increasing since 2002, while another commenter concluded that red knot numbers in Delaware Bay continue to decline.

Our Response:
We disagree with both of these conclusions. We find that peak counts from 2002 through 2008 continued to show a slight downward trend. Peak counts from 2009 through 2014 appear to have been stable to slightly increasing, despite lower confidence in these recent counts due to multiple shifts in methodology and surveyors. Average peak counts for the last decade (2005 to 2014) remain about 70 percent lower than during the baseline period of 1981 to 1983. See Supplemental Document, Population Surveys and Estimates—Spring Stopover Areas—Delaware Bay.

(42) Comment:
One State and several other commenters noted that the ARM model established a threshold of red knot abundance (45,000 or half of the historical peak counts) which, when reached, will trigger female crab harvest. As this threshold was derived from peak counts, it must be adjusted upward to account for differences in methods before it can be judged against new estimates of total stopover population derived from mark-resighting data. One State also commented that the mark-resighting method is of limited value in trend assessment because population estimates cannot be made retrospectively, but did acknowledge that it is probably the most robust method of estimating actual stopover population numbers and, therefore, will be useful in developing future trend information.

Our Response:
We agree that the threshold must be revised and note that this adjustment has already been made. This threshold, used in the ASMFC's management of the HSC fishery under the ARM, has now been adjusted upward to account for differences in methodology. In September 2013, the ASMFC's Delaware Bay Ecosystem Technical Committee adopted a ratio of 1.82, and adjusted the threshold from 45,000 to 81,900 red knots. This ratio may be refined when the ARM model is re-evaluated in the future (ASMFC 2013e, p. 1). We agree that this is a robust method of estimating stopover populations, but also agree that the mark-resighting method cannot yet be used for trend analysis because too few data points are available to date. No accurate estimates of the total stopover population using the methods of J. Lyons (pers. comm. September 3, 2013) can be calculated prior to 2011, when the required data began to be collected. However, estimates prior to 2011 are not needed to implement the ARM model as decisions on HSC harvest are based upon the current populations of HSCs and red knots. For red knot population trend analysis in Delaware Bay, we have relied on the peak counts (see
Our Responses 37
and
39.
)

(43) Comment:
One State said that it had difficulty evaluating the geographic adequacy of the winter surveys in Tierra del Fuego and the southern coastline of Argentina, because these surveys may or may not cover a sufficiently large portion of the wintering range to develop a comprehensive population estimate. This State questioned if it is possible that red knots winter outside of the surveyed area further north along the coast lines of Argentina and Chile, or on the Falkland Islands.

Our Response:
Much of what we know about the distribution of wintering red knots along the coasts of South America comes from Morrison and Ross (1989), who reported the results of aerial surveys conducted from 1982 to 1986. This survey effort covered nearly the entire Atlantic, Pacific, and northern coasts of South America (Morrison and Ross 1989, Vol. 1, p. 22). During these extensive surveys,
Calidris canutus
was observed only in Tierra del Fuego and the Patagonian coast of Argentina, the north coast of Brazil, and western Venezuela (Morrison and Ross 1989 Vol. 1, pp. 37, 40-41). Although Morrison and Ross (1989) did not observe
C. canutus
along the Pacific coast of South America, they recorded substantial numbers of unidentified medium-sized shorebirds in several locations, including some areas with reports of
C. canutus
from other sources (eBird.org 2014; Carmona
et al.
2013, pp. 175, 180; Ruiz-Guerra 2011, p. 194; Morrison and Ross 1989 Vol. 1, p. 40; Hughes 1979, pp. 51-52). In the proposed rule (Rufa Red Knot Ecology and Abundance, pp. 38-42), we presented the data of Morrison and Ross (1989) as well as all available results of more recent survey efforts for the known and possible range of
C.c. rufa,
which includes the east and north coasts of South America. These data have been updated in the Supplemental Document (Population Surveys and Estimates). Based on new information indicating that at least some of the
C. canutus
on the central Pacific coast of Chile are also
C.c. rufa,
we have also added best available abundance data for the west coast of South America (Population Surveys and Estimates—Central America and Pacific South America). We are unaware of any published or unpublished
C. canutus
reports from the Falkland Islands, there are no reports of these species for that area in eBird (eBird.org 2014), and no other datasets for the Falkland Islands were provided during the comment period. The lack of data may be explained by an apparent lack of survey efforts.

(44) Comment:
One State commented that, based upon its review of the threats analysis published in the listing proposal, it does not find compelling evidence that the
rufa
subspecies of the red knot warrants listing as a federally threatened species throughout the eastern half of the United States. Other commenters stated that listing of the rufa red knot is not warranted based on a lack of compelling evidence in the proposed rule, and that the threatened determination relies on speculative future conditions. An additional commenter stated that a reasonable determination could also be made that adequate conservation measures already exist to reasonably protect red knot populations and that forecasting cumulative worst case scenarios to determine species risk does not meet the test of 50 CFR 424.4(a)(1) for adding a new species to the list of threatened and endangered species. Conversely, other commenters stated that we should list

the red knot as endangered or use our authorities for emergency listing, while another commenter mentioned that the previous change in the rufa red knot's listing priority number was no guarantee that it would be listed.

Our Response:
See
Our Responses 27, 36, and 71
regarding how we satisfied the Act's information standard. The proposed rule and its underlying data were available for extensive public and peer review and comment. The commenters did not provide additional substantive information to refute our analysis or assumptions. We disagree that this listing determination relies on cumulative-worst case scenarios, and instead find that the red knot meets the definition of a threatened species based on several population-level threats. Particularly considering the cumulative effects of ongoing and emerging threats, and considering that several populations of red knots have already undergone considerable declines and remain at low levels, we conclude that the best available data constitute compelling scientific evidence that the red knot meets the definition of a threatened species.

As noted in the proposed rule (Previous Federal Actions, p. 2), the listing priority number was changed (from 6 to 3) in 2008. The commenter is correct that candidate species of any listing priority number are not guaranteed to be listed—new information may become available that causes us to change our conclusion that listing is warranted. However, this is not the case for the red knot. As for the need to emergency list, this request is moot because the red knot will become listed as threatened upon the effective date of this rule. As noted in the proposed rule (Previous Federal Actions, pp. 1-2), we previously determined that emergency listing was not warranted, and we had no new information to indicate emergency listing was warranted at the time of, or subsequent to, the proposed rule.

We have carefully reviewed all new information since the proposed rule, and continue to find that the red knot meets the definition of a threatened species under the Act. We do not find that the red knot warrants listing as endangered based largely on the fact that red knot populations in Tierra del Fuego and Delaware Bay, although still at historically low levels, appear to have stabilized since about 2009, suggesting that the red knot is not currently at risk of extinction, but is likely to become so in the foreseeable future.

(45) Comment:
One State and an additional commenter expressed concerns that threats in other habitats outside of Delaware Bay are having a disproportionate effect on the red knot because the Delaware Bay remains in a “depauperate state,” at least as it pertains to shorebirds (
i.e.,
HSC population levels are too low to provide the “super-abundance of eggs”). Because of this egg insufficiency, threats in other habitats used during the red knot's annual cycle will have a proportionately greater effect on red knot population viability. Thus, addressing the HSC egg food supply in the bay must remain at the forefront of red knot recovery efforts.

Our Response:
We disagree that the bay is currently “depauperate” for shorebirds, but agree that the HSC egg supply should remain a focus of red knot recovery work. As noted in the proposed rule (78 FR 60024, p. 60063), most data suggest that the volume of HSC eggs is currently sufficient to support the Delaware Bay's stopover population of red knots at its present size. This conclusion seems to be holding, as red knot weight gain was good during spring 2014, for a third consecutive year (A. Dey pers. comm. July 23, 2014). However, it is not yet known if the egg resource will continue to adequately support red knot population growth over the next decade. Thus, we agree that sustained focus on protecting the red knot's food supply is vital to the recovery of the red knot, and will be addressed during the recovery planning process. Further, we intend to continue our active role in the ASMFC's management of the HSC fishery. Under the ARM we do not anticipate the bait harvest will slow red knot population growth (see
Our Response 48
) (Smith
et al.
2013, p. 8).

We also agree that a number of other threats are likely contributing to habitat loss, anthropogenic mortality, or both, and thus contribute to the red knot's threatened status, particularly considering the cumulative effects of these threats, and that populations of this species have already undergone considerable declines in key areas.

(46) Comment:
One State and several other commenters stated that the Delaware Bay HSC population has not recovered and concluded that management of this fishery to date has not accomplished its objectives and has proven inadequate to reverse declines. Several commenters noted that no class of HSC (by sex or age) has shown any recovery as measured by the Virginia Tech Horseshoe Crab Trawl Survey or the Delaware Bay 16-foot Trawl Survey. Further, positive trends in female HSC populations are absent, even after 7 years of male-only harvest, which is consistent with significant unaccounted losses of female crabs, for example, from mortality caused by biomedical harvest, poaching, and bycatch. In addition, one State commented that the 2013 defunding of the Virginia Tech Trawl Survey adds to uncertainty that the data sources relied upon in the ARM models will be consistently available. In contrast, one commenter stated that, while the benthic trawl survey is the best survey to support the ARM, a sound strategy has been developed to use the NEAMAP data to support the 2014 modeling efforts for the 2015 fishery, and the ASMFC Horseshoe Crab Management Board and ARM Working Group anticipate the continued use of the ARM framework for management.

Our Response:
Numerous data sets are available regarding the Delaware Bay HSC population. We rely on ASMFC's periodic stock assessments to appropriately weigh and statistically analyze these data sets to draw conclusions regarding HSC population trends, as discussed in the proposed rule (78 FR 60024, p. 60066). The Supplemental Document (Factor E—Reduced Food Availability—Horseshoe Crab Harvest—Link A, Part 2) has been updated to include the results of the 2013 stock assessment update. The 2013 stock assessment update concluded that, in the Delaware Bay Region, there is evidence of increases in certain age or sex classes, but overall population trends have been largely stable (neither increasing nor decreasing) since the previous stock assessment in 2009 (ASMFC 2013b, p. 22). These 2013 stock assessment findings are consistent with our conclusions in the proposed rule (78 FR 60024, p. 60066) that HSC population declines were observed during the 1990s, increases (though not a full return to 1980s levels) and stabilization occurred in the early 2000s, and various data sets have differed with no consistent trends since 2005. We note that the ARM framework does not define a “recovery” population level for Delaware Bay HSCs, but instead seeks to set the crab harvest at a level that does not slow the achievement of an agreed-upon red knot population target.

We disagree that ASMFC's regulatory approach has been inadequate. In addition to restricting harvests through the Fisheries Management Plan (including the most recent iteration, the ARM), the ASMFC has taken several proactive steps including establishment of a Technical Committee to focus on shorebirds, requesting the establishment of an HSC reserve in Federal waters, supporting work on alternative baits, and reducing demand by promoting bait-saving devices. These efforts

reduced reported landings (ASMFC 2009a, p. 1) from 1998 to 2011 by more than 75 percent (78 FR 60024, p. 60064). We believe it is premature to state that the ASMFC's regulatory approach has not accomplished its objectives. Rather, we anticipate that this regulatory approach, currently reflected in the ARM framework, will allow for HSC and red knot population growth to meet ASMFC objectives. However, even highly successful harvest management under the ARM will only meet its objectives to the extent that the HSC population remains limited by harvest. For example, food resources, habitat conditions, and other conditions that affect growth, survival, and

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2014-28338. Public record. Not legal advice.