# Endangered and Threatened Wildlife and Plants; Threatened Species Status for Eastern Black Rail With a Section 4(d) Rule

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/fr%3A2020-19661

## Record

- **Collection:** Federal Register
- **Document type:** Rule
- **Published:** October 8, 2020
- **Citation:** 85 FR 63764

## Text

DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2018-0057; FF09E21000 FXES11110900000 201]
RIN 1018-BD21
Endangered and Threatened Wildlife and Plants; Threatened Species Status for Eastern Black Rail With a Section 4(d) Rule

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), determine threatened species status for the eastern black rail (
Laterallus jamaicensis jamaicensis
) under the Endangered Species Act of 1973 (Act), as amended. Accordingly, we list the eastern black rail, a bird subspecies known from as many as 35 States, the District of Columbia, Puerto Rico, Canada, Brazil, and several countries in the Caribbean and Central America, as a threatened species under the Act. The effect of this regulation will be to add this subspecies to the List of Endangered and Threatened Wildlife. We also finalize a rule under the authority of section 4(d) of the Act that provides measures that are necessary and advisable to provide for the conservation of the eastern black rail. We have determined that designation of critical habitat for the eastern black rail is not prudent.

DATES:

This rule is effective November 9, 2020.

ADDRESSES:

This final rule is available on the internet at
http://www.regulations.gov
in Docket No. FWS-R4-ES-2018-0057 and at the South Carolina Ecological Services Field Office. Comments and materials we received, as well as supporting documentation we used in preparing this rule, are available for public inspection in the docket on
http://www.regulations.gov.
Comments, materials, and documentation that we considered in this rulemaking will also be available by appointment, during normal business hours at: U.S. Fish and Wildlife Service South Carolina Ecological Services Field Office, 176 Croghan Spur Road, Suite 200, Charleston, SC 29407; telephone 843-727-4707.

FOR FURTHER INFORMATION CONTACT:

Tom McCoy, Field Supervisor, South Carolina Ecological Services Field Office, 176 Croghan Spur Road, Suite 200, Charleston, SC 29407; telephone 843-727-4707. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.
Under the 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.

What this document does.
This rule will list the eastern black rail (
Laterallus jamaicensis jamaicensis
) as a threatened species and provide measures under section 4(d) of the Act that are tailored to our current understanding of the conservation needs of the eastern black rail.

The basis for our action.
Under the 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 habitat loss and destruction, sea level rise and tidal flooding, incompatible land management, and increasing storm intensity and frequency are the primary threats to this subspecies.

Peer review and public comment.
We prepared a species status assessment report (SSA report) for the eastern black rail (Service 2019). The SSA report represents a compilation and assessment of the best scientific and commercial information available concerning the status of the eastern black rail, including the past, present, and future factors influencing the subspecies (Service 2019, entire). We solicited independent peer review of the SSA report by 10 individuals with expertise in rail biology and ecology and in species modeling; we received comments from 5 of the 10 reviewers. The reviewers were generally supportive of our approach and made suggestions and comments that strengthened our analysis. We also considered all comments and information received during the comment period. The SSA report and other materials relating to this rule can be found at
http://www.regulations.gov
under Docket No. FWS-R4-ES-2018-0057.

Previous Federal Actions

Please refer to the proposed listing rule for the eastern black rail (83 FR 50610) for a detailed description of previous Federal actions concerning this species.

Background

A thorough review of the taxonomy, life history, and ecology of the eastern black rail is presented in the SSA report (Service 2019, entire). Please refer to the proposed listing rule for the eastern black rail (83 FR 50610, October 9, 2018) for a summary of species information.

Summary of Biological Status and Threats

We completed a comprehensive assessment of the biological status of the eastern black rail, and prepared a report of the assessment (SSA report; Service 2019, entire), which provides a thorough account of the subspecies' overall viability. Below, we summarize the key results and conclusions of the SSA report, which can be viewed under Docket No. FWS-R4-ES-2018-0057 at
http://www.regulations.gov.

To assess eastern black rail viability, we used the three conservation biology principles of resiliency, representation, and redundancy (together, “the three Rs,” (3Rs)) (Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency refers to the ability of a species to withstand environmental and demographic stochasticity (for example, wet or dry years); representation refers to the ability of the species to adapt over time to long-term changes in the environment (for example, climate change); and redundancy refers to the ability of the species to withstand catastrophic events (for example, hurricanes). In general, the more redundant and resilient a species is and the more representation it has, the more likely it is to sustain populations over time, even under changing environmental conditions. Using these principles, we identified the eastern black rail's ecological requirements for survival and reproduction at the individual, population, and subspecies levels, and described the beneficial and risk factors influencing the subspecies' viability.

We delineated analysis units for the eastern black rail based on environmental variables (aquifer permeability, slope, mean precipitation, mean potential evapotranspiration, and percent sand in soil). We used 8,281 point localities from combined datasets (
i.e.,
eBird, Center for Conservation Biology, University of Oklahoma, and additional research partners) from 1980

through 2017, to delineate the analysis units for the eastern black rail. We named the analysis units using standard topographic and ecological landmarks: New England, Mid-Atlantic Coastal Plain, Appalachians, Southeast Coastal Plain, Southwest Coastal Plain, Central Lowlands, and Great Plains. Based on available data, we have concluded that the New England, Appalachians, and Central Lowlands analysis units are effectively extirpated. While these three analysis units historically did not support abundances of the eastern black rail as high as the other four analysis units, an evaluation of the current status information, including the paucity of current records, negative survey results, and the demonstrated range contraction throughout these areas, supports our conclusion that the eastern black rail is effectively extirpated from these analysis units. The remaining four analysis units, the Mid-Atlantic Coastal Plain, Southeast Coastal Plain, Southwest Coastal Plain, and Great Plains, have records of current populations of eastern black rails.

To assess resiliency, we analyzed occupancy within the analysis units through the creation of a dynamic occupancy model. We used data from repeated presence/absence surveys across the range of the eastern black rail to estimate the probability of presence at a site and related the occupancy probability to environmental covariates of interest (wettest month precipitation, temperature range, annual mean temperature, coldest month mean temperature, presence/absence of fire ants, and State identification). The lower the occupancy probability in an analysis unit, the less resiliency that analysis unit exhibits. We found the four extant analysis units (Southeast Coastal Plain, Mid-Atlantic Coastal Plain, Great Plains, and Southwest Coastal Plain) to have very low occupancy probabilities ranging from 0.099 to 0.25. The results also indicated fairly high site extinction probabilities with accompanying low site persistence.

To assess representation, we used two metrics to estimate and predict representative units that reflect the subspecies' adaptive capacity: Habitat variability and latitudinal variability. The eastern black rail exhibits adaptive potential by using similar habitat elements within different wetland types (habitat variability) within analysis units,
i.e.,
higher elevation areas within wetlands with dense vegetation, moist soils, and shallow flood depths (Eddleman
et al.
1988, p. 463; Nadeau and Conway 2015, p. 292). Therefore, the subspecies shows a level of adaptive capacity by using different wetland types that contain the required habitat elements. Additionally, we used the metric of latitudinal variability to reflect the eastern black rail's wide range across the contiguous United States. To maintain existing adaptive capacity, it is important to have resilient populations (analysis units) that exhibit habitat variability and latitudinal variability.

To assess redundancy, we evaluated the current distribution of eastern black rail analysis units through their present-day spatial locations. To have high redundancy, the eastern black rail would need to have multiple resilient analysis units spread throughout its range.

Current Condition of Eastern Black Rail

Historically, the eastern black rail ranged across the eastern, central, and southern United States; historical records also exist from the Caribbean, Central America, Brazil, and Ontario, Canada. It occupied multiple areas of wetlands (including salt marshes, coastal prairies, and hay fields) throughout the range; approximately 90 percent of documented breeding-season occurrence records occurred at coastal locations and less than 10 percent were inland records, with more than 60 percent of the inland records occurring before 1950 (Watts 2016, entire). The eastern black rail also occupied multiple areas of wetlands within each analysis unit.

Within the northeastern United States, historical (1836-2010) records document the eastern black rail as present during breeding months from Virginia to Massachusetts, with 70 percent of historical observations (773 records) in Maryland, Delaware, and New Jersey (Watts 2016, p. 22). Maryland, Delaware, and New Jersey are considered historical strongholds for eastern black rail in this region of the United States (the Northeast) as well as across the subspecies' entire breeding range (Watts 2016, p. 22), due to the total number and frequency of observations reported over time. Virginia, New York, and Connecticut account for an additional 21 percent of the historical records (235 records) from the Northeast (Watts 2016, p. 22). Recent (2011-2016) records from the Northeast are low in number (64 records), with almost all records restricted to outer coastal habitats (Watts 2016, pp. 22, 24). The distribution of the recent records points toward a substantial southward contraction in the subspecies' range of approximately 450 kilometers (280 miles), with vacated historical sites from 33 counties extending from the Newbury marshes in Massachusetts to Ocean County, New Jersey (Watts 2016, pp. 24, 119). Further, the distribution of the recent records has become patchy along the Atlantic coast, and an evaluation of the records within the 15 counties still currently occupied suggests an almost full collapse of the eastern black rail population in the Northeast (Watts 2016, p. 24).

While the Appalachians and Central Lowlands analysis units supported less habitat for eastern black rails compared to the more coastal analysis units, interior occurrences were more common historically. Current population estimates for states with a large area occurring within the boundaries of the Appalachians analysis unit are effectively zero (Watts 2016, p. 19). Within that unit, an estimated 0 to 5 breeding pairs currently occur in Pennsylvania, and no breeding pairs are thought to occur in New York or West Virginia (Watts 2016, p. 19). Birds previously detected in the Appalachians analysis unit were found in small depressional wetlands within active pastures; other freshwater wetlands dominated by cattails, rushes, or sedges; and drainage ditches (Watts 2016, pp. 48, 74). While these wetland types still exist within the analysis unit and may support single individuals or a very low-density, scattered population (Watts 2016, pp. 48, 74), a substantial amount of this kind of habitat has been lost primarily due to the draining of freshwater wetlands for agricultural purposes. These estimates likely hold true for the interior portions of the other States within the Appalachians analysis unit (
e.g.,
Georgia, Virginia) based on few current detections. Similar losses of habitat have occurred in the Central Lowlands analysis unit, and there are currently few detections of eastern black rails across this unit. Moreover, the current detections are not consistent from year to year even when habitat remains suitable. For example, Indiana Department of Natural Resources surveys for eastern black rails at multiple sites during the period 2010-2016 yielded one detection at a single site previously known to support eastern black rails (Gillet 2017, unpublished data).

In the Chesapeake Bay region, the distribution of eastern black rail has contracted, and the counts of birds have declined. A series of systematic surveys for eastern black rails has been conducted around the Chesapeake Bay since the early 1990s (Watts 2016, pp. 59, 67). Surveys estimated 140 individuals in the 1990-1992 survey period, decreasing to 24 individuals in 2007, and only 8 individuals in 2014, a decline of over 90 percent in less than

25 years (taking into account the number of survey points; Watts 2016, p. 59; Brinker 2017, unpublished data). Of 328 points surveyed in Virginia in 2007, researchers detected 15 birds; a second round of surveys in 2014 yielded 2 detections at 134 survey points (including all survey points with positive occurrences in 2007), equating to a 67 percent decline over 7 years (corrected from Watts to take into account the number of survey points; Wilson
et al.
2015, p. 3; Watts 2016, pp. 67, 71;).

Historically, the eastern black rail was also present during breeding months at inland and coastal locations throughout southeastern coastal States (the Southeast), a region that included North Carolina, South Carolina, Georgia, Florida, Tennessee, Mississippi, Alabama, Louisiana, and Texas (Watts 2016, pp. 75-76). Of these States, Texas, Florida, South Carolina, and North Carolina contained 89 percent of all historical observations (734 records) (Watts 2016, p. 77). The other States (Georgia, Tennessee, Mississippi, Alabama, and Louisiana) either do not have a history of supporting eastern black rails consistently or are considered to be on the peripheries of known breeding areas (Watts 2016, p. 77).

Recently, there have been 180 records of eastern black rails during the breeding season, and at a coarse view, the same 4 southeastern States that substantially supported the subspecies historically still support the subspecies (Watts 2016, pp. 77, 79). However, North Carolina shows a severe decline in the number of occupied sites, with only four properties occupied in 2014-2015, down from nine in 1992-1993 (Watts 2016, p. 80). Additional surveys in 2017 yielded no new occupied coastal sites, and no birds were detected at inland/freshwater sites from two surveys in 2018 (Watts
et al.
2017, p. 3; Watts
et al.
2018b, p. 3). South Carolina shows a limited distribution, with two known occupied areas (Wiest 2018, pers. comm.) and an estimated 50 to 100 breeding pairs (Watts 2016, p. 19), leaving Texas and Florida as the current strongholds for the Southeast. At the time of the 2016 coastal assessment, it was surmised that coastal Georgia may support a breeding population of unknown size (Watts 2016, pp. 93-95); however, a coastwide survey in 2017 at 409 survey points in Georgia yielded no detections of eastern black rails (Watts
et al.
2018a, p. 3). Initial results from the 2018 field season in Georgia detected no black rails at inland or coastal locations; a total of 206 points had been visited (Watts
et al.
2018a, p. 4). A small population in inland Georgia was tracked during the breeding season from 1991 to 2010 until the population disappeared in 2011 for unknown reasons; observed young from this population remains the only evidence of definitive breeding in the State (Watts 2016, pp. 93-94; Sykes 2018, pers. comm.). Overall, across the Atlantic and Gulf Coasts, recent observations show poor presence inland and a widespread reduction in the number of sites used across coastal habitats (Watts 2016, p. 79).

The history of the subspecies' distribution in the interior continental United States is poorly known. Historical literature indicates that a wide range of interior States were occupied by the eastern black rail, either regularly or as vagrants (Smith-Patten and Patten 2012, entire). Eastern black rails are currently vagrants (casual or accidental) in Arkansas, Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Nebraska, New Mexico, Ohio, and Wisconsin (Smith-Patten and Patten 2012, entire). Presently, eastern black rails are reliably located within the Arkansas River Valley of Colorado (presumed breeder in the State) and in southcentral Kansas (confirmed breeder in the State) (Smith-Patten and Patten 2012, pp. 9, 17; Butler
et al.
2014, p. 22). In Colorado, the subspecies is encountered in spring and summer at Fort Lyon Wildlife Area, Bent's Old Fort, Oxbow State Wildlife Area, Bristol, and John Martin Reservoir State Park (Smith-Patten and Patten 2012, p. 10). Surveys conducted between April 15 and June 15, 2018, in southeastern Colorado detected at least one black rail during repeat surveys at 39 of 115 points and 17 of 66 marshes surveyed (Rossi and Runge 2018, p. 6). In Kansas, available information on the occurrence of eastern black rail suggests eight counties have confirmed breeding records, but Quivira National Wildlife Refuge (NWR) is the only known site with consistent or regular breeding activities (Thompson
et al.
2011, p. 123). In Oklahoma, occurrence mapping suggests that this subspecies had at a maximum a patchy historical distribution throughout the State. At present, it is possible that there is not sufficient suitable habitat or numbers of birds to constitute a true breeding population in Oklahoma (Smith-Patten and Patten 2018, p. 7).

Eastern black rail analysis units currently have low to no resiliency in the contiguous United States (Service 2019, pp. 79-82). The Great Plains, Southwest Coastal Plain, and Southeast Coastal Plain analysis units have low resiliency based on the dynamic occupancy model results, which indicate very low occupancy probabilities in each modeled analysis unit: 0.25 in the Southwest Coastal Plain, 0.13 in the Great Plains, and 0.099 in the Southeast Coastal Plain. The Mid-Atlantic Coastal Plain analysis unit currently exhibits very low resiliency for the eastern black rail. It supports fewer birds and has fewer occupied habitat patches than the Southeast Coastal Plain analysis unit. The remaining three analysis units, New England, Appalachians, and Central Lowlands, currently demonstrate no resiliency. These three units historically did not support abundances of the eastern black rail as high as the other four analysis units. There are currently insufficient detections to model these units; recent detections (2011 to present) are fewer than 20 birds for each analysis unit. An evaluation of current status information yields that eastern black rails are effectively extirpated from portions of the New England, Appalachians, and Central Lowlands analysis units that were once occupied. Lastly, resiliency is unknown for the Central America and Caribbean portion of the eastern black rail's range. However, the sparsity of historical and current records, including nest records, indicates that resiliency outside of the contiguous United States is likely low. All recent sightings in Central America and the Caribbean have been of adult eastern black rails; there are no reports of nests, chicks, or juveniles.

To assess current representation, we evaluated both habitat variability and latitudinal variability. When considering habitat variability, we determined the eastern black rail has a level of adaptive potential by using similar habitats elements (
i.e.,
higher elevation areas within wetlands with dense vegetation, moist soils, and shallow flood depth) within different wetland types within analysis units. However, there may be unknown factors that influence and affect the eastern black rail's use of wetland habitat, as not all apparently suitable wetland habitat is currently occupied. While the New England, Appalachians, and Central Lowlands analysis units have experienced wetland habitat loss and fragmentation, wetland habitats continue to be present on the landscape. However, the eastern black rail is not being found in these three analysis units with any consistency or by detections representing more than single individuals. Historically, the eastern black rail had a wide distribution and exhibited latitudinal variability. Currently, as discussed above, three of

the analysis units (New England, Appalachians, and Central Lowlands) are effectively extirpated, and, therefore, this latitudinal variability (higher latitudes) has effectively been lost to the subspecies. Therefore, even though the eastern black rail still occurs at varying latitudes, we conclude that the subspecies currently has reduced representation across its range.

Despite having a wide distribution, the eastern black rail currently has low redundancy across its range. With the loss of three analysis units in upper latitudes of the range, the subspecies has reduced ability to withstand catastrophic events, such as hurricanes and tropical storms, which could impact the lower latitudinal analysis units. Given the lack of habitat connectivity, and patchy and localized distribution, it would be difficult for the subspecies to recover from a catastrophic event in one or more analysis units.

Risk Factors for Eastern Black Rail

The Act directs us to determine whether any species is an endangered species or a threatened species because of any factors affecting its continued existence. Under section 4(a)(1) of the Act, we may list a species based on (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. These factors represent broad categories of natural or human-caused actions or conditions that could have an effect on a species' continued existence. In evaluating these actions and conditions, we look for those that may have a negative effect on individuals of the species, as well as other actions or conditions that may ameliorate any negative effects or may have positive effects.

We use the term “threat” to refer in general to actions or conditions that are known to or are reasonably likely to negatively affect individuals of a species. The term “threat” includes actions or conditions that have a direct impact on individuals (direct impacts), as well as those that affect individuals through alteration of their habitat or required resources (stressors). The term “threat” may encompass—either together or separately—the source of the action or condition or the action or condition itself.

The mere identification of any threat(s) does not necessarily mean that the species meets the statutory definition of an “endangered species” or a “threatened species.” In determining whether a species meets either definition, we must evaluate all identified threats by considering the expected response by the species, and the effects of the threats—in light of those actions and conditions that will ameliorate the threats—on an individual, population, and species level. We evaluate each threat and its expected effects on the species, then analyze the cumulative effect of all of the threats on the species as a whole. We also consider the cumulative effect of the threats in light of those actions and conditions that will have positive effects on the species—such as any existing regulatory mechanisms or conservation efforts. The Secretary determines whether the species meets the definition of an “endangered species” or a “threatened species” only after conducting this cumulative analysis and describing the expected effect on the species now and in the foreseeable future. We reviewed the potential risk factors (
i.e.,
threats or stressors) that are affecting the eastern black rail now and into the future. In this rule, we will discuss in detail only those threats that we conclude are driving the status and future viability of the species. The primary threats to eastern black rail are: (1) Habitat fragmentation and conversion, resulting in the loss of wetland habitats across the range (Factor A); (2) sea level rise and tidal flooding (Factors A and E); (3) land management practices (
i.e.,
incompatible fire management practices, grazing, and haying/mowing/other mechanical treatment activities) (Factors A and E); and (4) stochastic events (
e.g.,
extreme flooding, hurricanes) (Factor E). Human disturbance, such as birders using excessive playback calls of black rail vocalizations (Factor B), is also a concern for the species. Additional stressors to the species (including oil and chemical spills and environmental contaminants (Factor E); disease, specifically West Nile virus (Factor C); and predation and altered food webs resulting from invasive species (fire ants, feral pigs, nutria, mongoose, and exotic reptiles) introductions (Factor C)) are discussed in the SSA report (Service 2019, entire). However, although these additional stressors may be having localized impacts, they are not the primary drivers of the status of the subspecies, and so we do not discuss them in detail in this document. We also reviewed the conservation efforts being undertaken for the subspecies. The existing regulatory mechanisms do not address threats to the eastern black rail such that it does not warrant listing under the Act (Factor D).

Habitat Fragmentation and Conversion

The eastern black rail is a wetland-dependent bird requiring dense emergent cover (
i.e.,
vegetation) and extremely shallow water depths (typically ≤3 cm) over a portion of the wetland-upland interface to support its resource needs. Grasslands and their associated palustrine (freshwater) and estuarine wetland habitats have experienced significant loss and conversion since European settlement (Hannah
et al.
1995, pp. 137, 151; Noss
et al.
1995, pp. 57-76, 80-84; Bryer
et al.
2000, p. 232). Approximately 50 percent (greater than 100 million acres) of the wetlands in the conterminous United States have been lost over the past 200 years; the primary cause of this loss was conversion for agricultural purposes (Dahl 1990, p. 9). Wetland losses for the States within the eastern black rail's historical range have been from 9 percent to 90 percent, with a mean of 52 percent (Dahl 1990, p. 6). Similarly, most of the native grassland/prairie habitats associated with eastern black rail habitat have been lost since European settlement (Sampson and Knopf 1994, pp. 418-421).

The eastern black rail also uses the transition zone (ecotone) between emergent wetlands and upland grasslands. These transitional areas are critical to eastern black rails, as they provide refugia during high-water events caused by precipitation or tidal flooding. These habitat types have also experienced significant declines over time (Sampson and Knopf 1994, pp. 418-421), with many areas within the eastern black rail's historical range losing over 90 percent of their prairie habitat. Most of this loss can be attributed to agricultural conversion (Sampson and Knopf 1994, pp. 419-420). Many of the freshwater wetlands associated with these grasslands were emergent and ephemeral in nature, and would have supported eastern black rails. For example, in Texas, between the 1950s and 1990s, 235,000 acres, or 29 percent, of freshwater wetlands within Gulf coastal prairie were converted primarily to upland agriculture and other upland land uses (Moulton
et al.
1997, p. 5). This value does not include the numbers of upland prairie acres that were also converted.

Despite regulatory efforts to minimize the loss of wetland habitats, losses and alterations continue to occur to habitats occupied by the eastern black rail. Marshes continue to face substantial impacts from dikes, impoundments, canals, altered freshwater inflows,

erosion, relative sea level rise, tidal barriers, tropical storm events, and other natural and human-induced factors (Turner 1990, entire; Kennish 2001, entire; Adam 2002, entire; Tiner 2003, p. 513; Gedan
et al.
2009, entire). Estuarine emergent wetland losses are mostly attributable to conversion to open water through erosion (Dahl and Stedman 2013, p. 37), while freshwater emergent wetland losses appear to be the result of development (Dahl and Stedman 2013, p. 35). Marine and estuarine wetlands along the northern Gulf of Mexico have been negatively impacted by development, including energy development and coastal storms (Dahl 2011, p. 47). Because the rail is a wetland-dependent subspecies, the loss and alteration of palustrine and estuarine wetlands and associated grassland habitats have a negative impact.

Within the range of the eastern black rail, land use in the United States has affected and continues to affect groundwater and surface water resources (Johnston 1997, entire; McGuire 2014, pp. 1-2, 7, 9; Barfield 2016, pp. 2-4; Juracek and Eng 2017, pp. 1, 11-16). The conversion of wetland habitat, largely for agricultural use, was mentioned above. However, habitat conversion and land use directly and indirectly affect water resources, largely tied to the interaction of groundwater and surface water resources (Sophocleous 2002, entire; Tiner 2003, p. 495; Glazer and Likens 2012, entire; Konikow 2015, entire; U.S. Geological Survey (USGS) 2016, unpaginated).

Where groundwater resources are hydraulically connected to surface water resources, these connections can either be unconfined (water table) or confined (springs) aquifers. In unconfined aquifers, locations can support surface features such as wetlands or riparian habitats where groundwater is located near the land surface (Haag and Lee 2010, pp. 16-19, 21-24). Lowering of groundwater through withdrawals via wells or ditches can cause wetlands to shrink or become dry. Withdrawals of confined aquifers can lead to the drying of springs and associated wetland habitats (Weber and Perry 2006, p. 1255; Metz 2011, p. 2). In the central and southcentral United States, high groundwater use, largely attributed to cropland irrigation and other human activities, may affect the long-term sustainability of water resources, including causing wetland loss (McGuire 2014, entire; Juracek 2015, entire; Juracek and Eng 2017, entire; Juracek
et al.
2017, entire; Perkin
et al.
2017, entire).

Human modifications to the environment have led to significant changes in vegetation. Some of these modifications include water withdrawals and the construction of levees, drainage canals, and dams. Changes to native vegetation can result in changes to the structure of the habitat (
e.g.,
conversion from emergent to scrub-shrub wetlands, wetland into upland habitat, or vice-versa), as well as the introduction of invasive plant species (
e.g., Phragmites australis;
Crain
et al.
2009, p. 157). Given the narrow habitat preferences of the eastern black rail (
i.e.,
very shallow water and dense emergent vegetation), small changes in the plant community can easily result in habitat that is not suitable for the subspecies.

Subsidence (lowering of the earth's surface) is caused by the withdrawal of liquids from below the ground's surface, which relieves supporting hydraulic pressure of liquids by the long-term compression of unconsolidated, geologically deposited sediments, or by other geologic processes (White and Tremblay 1995, entire; Day
et al.
2011, p. 645; Karegar
et al.
2016, p. 3129). Localized subsidence can occur with groundwater withdrawals where withdrawal rates are greater than the aquifer recharge rates (White and Tremblay 1995, pp. 794-804; Morton
et al.
2006, p. 271) or where liquids associated with hydrocarbon extraction have caused the lowering of ground elevations (Morton
et al.
2006, p. 263). On the Atlantic coast, an area of rapid subsidence exists between Virginia and South Carolina, where the rate of subsidence has doubled due to increased groundwater withdrawals (Karegar
et al.
2016, pp. 3131-3132). An extreme example of subsidence in the United States is along the Gulf of Mexico coast, where both subsurface liquid withdrawal and sediment consolidation have significant influence on coastal wetland habitats (Turner 1990, pp. 93-94, 96, 98; White and Tremblay 1995, pp. 795-804; Morton
et al.
2006, entire). Subsidence combined with sea level rise is referred to as relative sea level rise, and the Gulf of Mexico has the highest relative sea level rise rates in the conterminous United States, leading to significant losses in wetland habitats (National Oceanic and Atmospheric Administration (NOAA) 2018, unpaginated).

Subsidence can affect the eastern black rail and its habitat in both fresh and tidal wetlands. Vegetated wetland habitats used by the eastern black rail can be converted to unvegetated open water or mudflats through drowning of vegetation or erosion from increased wave energy. Locations with higher subsidence rates can experience increased tidal flooding sooner than areas with lower subsidence rates (Sweet
et al.
2014, pp. 10-13). The effect of increased tidal flooding will change black rail habitat over time (
i.e.,
marsh migration) but can have direct impacts on black rail reproduction when flooding occurs during the breeding season (Erwin
et al.
2006, entire; Pol
et al.
2010, pp. 724-728).

Extensive drainage features have been created or modified in the United States, primarily to reduce flooding to protect agricultural land or infrastructure. These include excavation of drainage ditches, channelization of rivers and streams, construction of levees and berms, tidal restrictions, and diversions of waterways. Extensive areas of Florida were channelized in an effort to drain wetlands in the early 1900s (Renken
et al.
2005, pp. 37-56). Most, if not all, of the coastal plain in Texas contains existing drainage features that were either created or modified to reduce flooding of agricultural lands and associated communities. These features can reduce or eliminate the hydroperiod to sustain associated wetlands by removing water rapidly off the landscape (Blann
et al.
2009, pp. 919-924). In glaciated geographies such as the Midwest, drain tiles and other methods have been used to drain wetlands to improve conditions for agricultural production (Blann
et al.
2009, pp. 911-915). Approximately 90 percent of the salt marshes on the northeast United States coast have been ditched to control mosquitoes (Bourn and Cottam 1950, p. 15; Crain
et al.
2009, pp. 159-161). Ditching increases the area of the marsh that is inundated as well as drained (Daiber 1986, in Crain
et al..
2009, p. 160; Crain
et al.
2009, p. 160).

Levees have been constructed in flood-prone areas to minimize damage to crops and local communities. Levees can modify the duration, intensity, and frequencies of hydroperiods associated with riparian and tidal wetlands and thus change the nature and quality of wetland habitat, including that used by marsh-dependent species (Walker
et al.
1987, pp. 197-198; Bryant and Chabreck 1998, p. 421; Kuhn
et al.
1999, p. 624; Kennish 2001, p. 734; Adam 2002, p. 46). They also facilitate the movement patterns of mesopredators and improve their access to wetland habitats (Frey and Conover 2006, pp. 1115-1118). Navigation channels and their management have had extensive impacts to tidal wetlands (
e.g.,
in

Louisiana). These channels can modify the vegetation community of associated wetlands and can increase the frequency of extreme high tide or high flow events by providing a more direct connection to the influencing water body (Turner 1990, pp. 97-98; Bass and Turner 1997, pp. 901-902; Kennish 2001, pp. 734-737). Tidal restrictions, such as water control structures, bridges, and culverts built for the purposes of flood protection, restricting salt water intrusion, and modification of vegetation, have also affected coastal salt marshes.

All of these alterations to drainage affect the hydrology, sediment and nutrient transport, and salinities of wetland habitats used by the eastern black rail, which in turn affect the habitat's composition and structure. These changes can lead to instability in the duration and intensity of hydroperiods, affect associated vegetation communities, and impact the ability of marsh habitats to adapt to changing conditions. This situation affects the ability of the habitat to support populations of the eastern black rail, by exposing eastern black rails to unsuitable water regimes or converted habitats.

Sea Level Rise and Tidal Flooding

Representative concentration pathways (RCPs) are the current set of scenarios used for generating projections of climate change; for further discussion, please see the SSA report (Service 2019, entire). Recent studies project global mean sea level rise to occur within the range of 0.35 to 0.95 meters (m) (1.14 to 3.11 feet (ft)) for RCP 4.5, and within the range of 0.5 to 1.3 m (1.64 to 4.27 ft) for RCP 8.5, by 2100 (Sweet
et al.
2017b, p. 13). The Northeast Atlantic and western Gulf of Mexico coasts are projected to have amplified relative sea level rise greater than the global average under almost all future sea level rise scenarios through 2100 (Sweet
et al.
2017b, p. 43).

Sea level rise will amplify coastal flooding associated with both high tide floods and storm surge (Buchanan
et al.
2017, p. 6). High tide flooding currently has a negative impact on coastal ecosystems, and annual occurrences of high tide flooding have increased five- to ten-fold since the 1960s (Reidmiller
et al.
2018, p. 728). In addition, extreme coastal flood events are projected to increase in frequency and duration, and the annual number of days impacted by nuisance flooding is increasing, along the Atlantic and Gulf Coasts (Sweet
et al.
2017b, p. 23). Storm surges from tropical storms will travel farther inland.

Along the Texas Gulf Coast, relative sea level rise is twice as large as the global average (Reidmiller
et al.
2018, p. 969). Over the past 100 years, local sea level rise has been between 12.7 and 43.2 cm (5 to 17 in), resulting in an average loss of 73 hectares (180 acres) of coastline per year, and future sea level rise is projected to be higher than the global average (Runkle
et al.
2017b, p. 4; Reidmiller
et al.
2018, p. 972). In South Carolina, sea level has risen by 3.3 cm (1.3 in) per decade, nearly double the global average, and the number of tidal flood days has increased (Runkle
et al.
2017c, p. 4). Projected sea level rise for South Carolina is higher than the global average, with some projections indicating sea level rise of 1.2 m (3.9 ft) by 2100 (Runkle
et al.
2017c, p. 4). The number of tidal flood days are projected to increase and are large under both high and low emissions scenarios (Runkle
et al.
2017c, p. 4). Similarly, in Florida, sea level rise has resulted in an increased number of tidal flooding days, which are projected to increase into the future (Runkle
et al.
2017a, p. 4).

Even with sea level rise, some tidal wetlands may persist at slightly higher elevations (
i.e.,
“in place”) for a few decades, depending on whether plant primary productivity and soil accretion (which involves multiple factors such as plant growth and decomposition rates, buildup of organic matter, and deposition of sediment) can keep pace with the rate of sea level rise, thus avoiding “drowning” (Kirwan
et al.
2016, entire). Under all future projections, however, the rate of sea level rise increases over time (Sweet
et al.
2017a, pp. 342-345). A global analysis found that in many locations salt marsh elevation change did not keep pace with sea level rise in the last century and even less so in the past two decades, and concluded that the rate of sea level rise in most areas will overwhelm the capacity of salt marshes to persist (Crosby
et al.
2016, entire). Under this analysis, based on RCP 4.5 and RCP 8.5 scenarios and assuming continuation of the average rate of current accretion, projected marsh drowning along the Atlantic coast at late century (2081-2100) ranges from about 75 to 90 percent (Crosby
et al.
2016, p. 96, figure 2). The accretion balance (reported accretion rate minus local sea level rise) is negative for all analyzed sites in the Louisiana Gulf Coast and for all but one site in the mid-Atlantic area (figures 3c and 3d in Crosby
et al.
2016, p. 97); both of these areas are part of the range of the eastern black rail.

Sea level rise will reduce the availability of suitable habitat for the eastern black rail and overwhelm habitat persistence. Sea level rise and its effects (
e.g.,
increased flooding and inundation, salt water intrusion) may affect the persistence of coastal or wetland plant species that provide habitat for the eastern black rail (Warren and Niering 1993, p. 96; Morris
et al.
2002, p. 2876). Increased high tide flooding from sea level rise, as well as the increase in the intensity and frequency of flooding events, will further impact habitat and directly impact eastern black rails through nest destruction and egg loss (Sweet
et al.
2017b, pp. 35-44).

Land Management Practices (Fire Management, Haying, Mowing, and Other Mechanical Treatment Activities, and Grazing)

Fire Management

Fire suppression has been detrimental to habitats used by the eastern black rail by allowing encroachment of woody plants. Without fire or alternate methods of disturbing grassland and emergent wetland vegetation such as mowing or rotational grazing, the amount of preferred habitat for eastern black rails is expected to continue to decrease in some regions due to encroachment by woody vegetation, such as coastal Texas (Grace
et al.
2005, p. 39). Therefore, prescribed (controlled) fire is one tool to maintain and restore habitat for this subspecies at the desired seral stage (intermediate stages of ecological succession).

While fire is needed for the maintenance of seral stages for multiple rail species, the timing and frequency of the burns, as well as the specific vegetation types targeted, can lead to undesirable effects on rail habitats in some cases (Eddleman
et al.
1988, pp. 464-465). Burning salt marshes during drought or while the marshes are not flooded can result in root damage to valuable cover plants (Nyman and Chabreck 1995, p. 138). Controlled burning of peat, or accumulated organic litter, when marshes are dry has resulted in marsh conversion to open water due to the loss of peat soils. Variations in soil type supporting the same plant species may lead to differing recovery times post-burn, and therefore potentially unanticipated delays in the recovery of black rail habitat (McAtee et al. 1979, p. 375). Simply shifting the season of burn may alter plant species dominance and the associated structure available to the eastern black rail, as is seen with spring fire conversion of chairmaker's bulrush (
Schoenoplectus americanus
) to salt meadow cordgrass

(
Spartina patens
) (Nyman and Chabreck 1995, p. 135).

Prescribed fire at any time of the year may result in mortality to adult and juvenile birds, as well as eggs and chicks during the breeding season. Fall and winter burns are more likely to avoid reproductive season impacts (Nyman and Chabreck 1995, p. 138). When burning is needed during the nesting season (for example, brush control), loss of eggs and chicks can be reduced by limiting the proportion of eastern black rail habitat to be burned within a management boundary. Incorporating additional best management practices (BMPs) such as leaving unburned refugia within a controlled burn and planning burn rotations so that adjacent suitable habitat is present to accommodate these rails post-burn, are important at all times of the year to reduce mortality of birds.

Fire pattern can have profound effects on birds. Controlled burns can result in indirect rail mortality, as avian predators attracted to smoke are able to capture rails escaping these fires (Grace
et al.
2005, p. 6). Because eastern black rails typically prefer concealment rather than flight to escape threats, the birds may attempt to escape to areas not affected by fire, such as wetter areas or adjacent areas not under immediate threat. Ring, expansive, or rapidly moving fires are therefore not conducive to rail survival (Grace
et al.
2005, p. 9; Legare
et al.
1998, p. 114). On the other hand, controlled burns designed to include unburned patches of cover (refugia) may positively influence eastern black rail survival. For example, in Florida, a mosaic of unburned vegetation patches (refugia) 0.1 to 2.0 ac in size facilitated eastern black rail survival during a 1,600-ac controlled burn during the late summer, whereas a controlled burn of a 2,400-ac marsh during the winter resulted in direct mortality of 34 eastern black rails when refugia areas were not provided (Legare
et al.
1998, p. 114; Legare 2018, pers. comm.). Prescribed fires that include patches of unburned habitat (refugia) scattered throughout provide escape cover for wildlife, including, but not limited to, eastern black rails (Legare
et al.
1998, p. 114). Unburned strips of vegetation bordering the inside perimeters of burn units also are believed helpful as escape cover from both fire and avian predators (Grace
et al.
2005, p. 35). Coastal marshes that are burned in staggered rotations to create a mosaic of different seral stages or are burned less frequently will continue to provide cover for marsh species, such as the eastern black rail (Block
et al.
2016, p. 16).

Haying, Mowing, and Other Mechanical Treatment Activities

Haying, mowing, and other mechanical treatment activities are used throughout the range of the eastern black rail. Mechanical treatment activities maintain grasslands by reducing woody vegetation encroachment, which may provide suitable habitat for eastern black rails. However, these practices can have detrimental impacts to wildlife when used too frequently or at the wrong time of year (Beintema and Muskens 1987, p. 755; Bollinger
et al.
1990, p. 148; Arbeiter
et al.
2017, pp. 554-566). For example, at Quivira NWR in Kansas, haying at a frequency of once or twice per year resulted in no occupancy of hayed habitats by eastern black rails during the following year (Kane 2011, pp. 31-33). Further, haying or mowing timed to avoid sensitive stages of the life cycle (nesting and molt period) would be less detrimental to eastern black rails (Kane 2011, p. 33). Eastern black rails reproduce from approximately mid-March through September across a latitudinal gradient, and mechanical treatment activities during this time period disturbs eastern black rail adults and can potentially crush eggs and chicks. As with fire, when mechanical treatment activities are alternated to allow mosaics of treated and untreated habitat at all times, the site can continue to support cover-dependent wildlife (Tyler
et al.
1998, pp. 45-49; Kleijn
et al.
2010, pp. 476, 484; Arbeiter
et al.
2017, pp. 562-566).

Grazing

Grazing, predominately by cattle, occurs on public and private lands throughout the range of the eastern black rail. Because eastern black rails occupy drier areas in wetlands and require dense cover, these birds are believed to be more susceptible to grazing impacts than other rallids (Eddleman
et al.
1988, p. 463). Based on current knowledge of grazing and eastern black rail occupancy, the specific timing, duration, and intensity of grazing will result in varying impacts to the eastern black rail and its habitat. Light-to-moderate grazing may be compatible with eastern black rail occupancy under certain conditions, while intensive or heavy grazing is likely to have negative effects on eastern black rails and the quality of their habitat, specifically if the dense overhead cover that the bird requires is removed. It may benefit black rail habitat (or at least not be detrimental) when herbaceous plant production is stimulated (Allen-Diaz
et al.
2004, p. 147) and the necessary overhead cover is maintained. In Kansas, eastern black rails were documented in habitats receiving rotational grazing during the nesting season that preserved vegetation canopy cover (Kane 2011, pp. 33-34). Black rails occur in habitats receiving light-to-moderate grazing (
i.e.,
Kane 2011; Richmond
et al.
2012; Tolliver 2017). These results suggest that such grazing is an option for providing disturbance, which may promote black rail occupancy. However, cattle grazing at high intensities may not favor black rail occupancy, as heavy grazing or overgrazing reduces the wetland vegetation canopy cover (Richmond
et al.
2010, p. 92).

In addition to the loss of vegetation cover and height (Chabreck 1968, p. 56; Whyte and Cain 1981, p. 66; Kirby
et al.
1986, p. 496; Yeargan 2001, p. 87; Martin 2003, p. 22), grazing may also have direct negative effects on eastern black rails by livestock disturbing nesting birds or trampling birds and nests (Beintema and Muskens 1987, p. 755; Eddleman
et al.
1988, p. 463; Jensen
et al.
1990, pp. 73-74; Durham and Afton 2003, p. 438; Mandema
et al.
2013, pp. 412-415). Heavy disturbance from grazing can also lead to a decline in eastern black rail habitat quality through soil erosion (Walker and Heitschmidt 1986, pp. 428, 430; Warren
et al.
1986a, p. 486; Weltz and Wood 1986, p. 263), decreased sediment accumulation and increased soil compaction (Andresen
et al.
1990, p. 146; Esselink
et al.
2002, p. 27), diminished water infiltration (Warren
et al.
1986b, p. 500), and increased salinities eventually leading to habitat conversion (Esselink
et al.
2002, p. 28).

Stochastic Events (Extreme Weather Events)

Extreme weather effects, such as storms associated with frontal boundaries or tropical disturbances, can also directly affect eastern black rail survival and reproduction, and can result in direct mortality. Tropical storms and hurricanes are projected to increase in intensity and precipitation rates along the North Atlantic coast and Gulf Coast (Bender
et al.
2010, p. 458; Kossin
et al.
2017, pp. 259-260). The frequency of Category 4 and 5 tropical storms is predicted to increase despite an overall decrease in the number of disturbances (Bender
et al.
2010, pp. 457-458). Storms of increased intensity, which will have stronger winds, higher storm surge, and increased flooding, cause significant damage to coastal habitats by destroying vegetation and

food sources, as well as resulting in direct mortality of birds. For example, Hurricane Harvey flooded San Bernard NWR in Texas with storm surge, which was followed by runoff flooding from extreme rainfall. This saltmarsh, occupied by eastern black rails, was inundated for several weeks (Woodrow 2017, pers. comm.). Increases in storm frequency, coupled with sea level rise, may result in increased predation exposure of adults and juveniles if they emerge from their preferred habitat of dense vegetation (Takekawa
et al.
2006, p. 184). Observations show predation upon California black rails during high tides when the birds had minimal vegetation cover in the flooded marsh (Evens and Page 1986, p. 108).

Weather extremes associated with climate change can have direct effects on the eastern black rail, leading to reduced survival of eggs, chicks, and adults. Indirect effects on the eastern black rail are likely to occur through a variety of means, including long-term degradation of both inland and coastal wetland habitats. Other indirect effects may include loss of forage base of wetland-dependent organisms. Warmer and drier conditions will most likely reduce overall habitat quality for the eastern black rail. Because eastern black rails tolerate a narrow range of water levels and variation within those water levels, drying as a result of extended droughts may result in habitat becoming unsuitable, either on a permanent or temporary basis (Watts 2016, p. 120). Extreme drought or flooding conditions may also decrease bird fitness or reproductive success by reducing the availability of the invertebrate prey base (Hands
et al.
1989, p. 5; Davidson 1992, p. 129). Lower rates of successful reproduction and recruitment lead to further overall declines in population abundance and resiliency to withstand stochastic events such as extreme weather events. The vulnerability of the eastern black rail to the effects of climate change depends on the degree to which the subspecies is susceptible to, and unable to cope with, adverse environmental changes due to long-term weather trends and more extreme weather events.

Human Disturbance

Human disturbance can stress wildlife, resulting in changes in distribution, behavior, demography, and population size (Gill 2007, p. 10). Activities such as birding and hiking, have been shown to disturb breeding and nesting birds. Disturbance may result in nest abandonment, increased predation, and decreased reproductive success, and in behavioral changes in non-breeding birds. Singing activity of breeding male birds declined in sites that experienced human intrusion, although the response varied among species and level of intrusion (Gutzwiller
et al.
1994, p. 35). At the Tishomingo NWR in Oklahoma, recreational disturbances of migratory waterbirds accounted for 87 percent of all disturbances (followed by natural disturbances (10 percent) and unknown disturbances (3 percent)) (Schummer and Eddleman 2003, p. 789).

Many birders strive to add rare birds to their “life list,” a list of every bird species identified within a birder's lifetime. Locations of rare birds are often posted online on local birding forums or eBird, leading to an increased number of people visiting the location in an attempt to see or hear the bird. Due to its rarity, the eastern black rail is highly sought after by birders (Beans and Niles 2003, p. 96). Devoted birders may go out of their way to add an eastern black rail to their life list (McClain 2016, unpaginated). The efforts of birders to locate and identify rare birds, such as the eastern black rail, can have both positive and negative impacts on the bird and its habitat. Birders play an especially important role in contributing to citizen science efforts, such as the eBird online database, and have helped further our understanding of species' distributions and avian migration ecology in crucial ways (Sullivan
et al.
2014, entire). Birders have provided valuable location information for eastern black rails that might have otherwise gone undetected and have made these records publicly available (see eBird's black rail account; eBird 2017, unpaginated).

While amateur and professional birding have made important contributions to our understanding of rare species like the eastern black rail, some birders may be more likely to pursue a sighting of a rare bird, as they may perceive the benefits of observing the bird to outweigh the impacts to the bird (Bireline 2005, pp. 55-57). As a result, methods may be employed to increase the likelihood of observing a rare bird, including the use of vocalized calls or audio recordings, as is the case for eastern black rails, or approaching birds in order to get a sighting (Beans and Niles 2003, p. 96; Bireline 2005, p. 55). These methods have the potential to disturb nesting birds or trample nests or eggs, and may lead to increased predation (Beans and Niles 2003, p. 96).

With the prevalence of smartphones, the use of playback calls has increased as recordings of birds are readily available on the internet, and birding websites and geographic site managers (State, Federal, or nongovernmental organizations) often provide guidance on the use of playback calls (Sibley 2001, unpaginated). The American Birding Association's Code of Birding Ethics encourages limited use of recordings and other methods of attracting birds, and recommends that birders never use such methods in heavily birded areas or for attracting any species that is endangered, threatened, of special concern, or rare in the local area (American Birding Association 2018, unpaginated). While most birders likely follow these ethical guidelines, using playback calls of eastern black rail vocalizations in attempts to elicit responses from the birds and potentially lure them into view is commonly done outside of formal eastern black rail surveys (eBird 2017, unpaginated). Due to the rarity of the eastern black rail, a few cases of trespassing are known from people looking for the bird (
e.g.,
Kerlinger and Wiedner 1990, p. 62). Trespassing has been documented on private lands and in areas on public lands specifically closed to the public to protect nesting eastern black rails (Hand 2017, pers. comm.; Roth 2018, pers. comm.). Trespassing may not only disturb the bird, but can also result in trampling of the bird's habitat, as well as of eggs and nests. Some State resource managers and researchers have expressed concern that releasing locations of eastern black rail detections may increase human disturbance and harassment of the subspecies. The potential for human disturbance varies by site and is likely less of an issue for areas that are remote and difficult to access.

Synergistic Effects

It is likely that several stressors are acting synergistically or additively on the subspecies. The combination of multiple stressors may be more harmful than a single stressor acting alone. For the eastern black rail, a combination of stressors result in habitat loss, reduced survival, reduced productivity, and other negative impacts on the subspecies. Sea level rise, coupled with increased tidal flooding, results in the loss of the high marsh habitat required by the subspecies. Land management activities, such as prescribed burning, that are conducted without maintaining dense overhead cover or providing refugia in eastern black rail habitat will further exacerbate impacts. If these combined stressors occur too often within and across generations, they will limit the ability of the subspecies to maintain occupancy at habitat sites, which may become lost or unsuitable for the subspecies and limit its ability to

colonize other previously occupied sites or new sites. For example, tidal marshes in Dorchester County, Maryland, in the Chesapeake Bay (specifically the areas of Blackwater NWR and Elliott Island) served as one of the most well-known former strongholds for the eastern black rail (Watts 2016, p. 22). These marshes have and continue to experience marsh erosion from sea level rise, prolonged flooding, a lack of a sufficient sediment supply, and land subsidence, as well as habitat destruction from nutria (
Myocastor coypus;
now eradicated) and establishment of the invasive common reed (
Phragmites australis
). On Elliott Island, high decadal counts of eastern black rails have declined from the hundreds in the 1950s to no birds detected in recent years (from 2012-2015 the peak count was a single bird, and no birds were detected in 2016) (Watts 2016, pp. 61-62).

Regulations and Conservation Efforts

Federal Protections

The Migratory Bird Treaty Act of 1918 (MBTA; 16 U.S.C. 703
et seq.
) provides specific protection for the eastern black rail, which is a migratory bird under the statute. The MBTA makes it illegal, unless permitted by Federal regulation, “by any means or in any manner, to pursue, hunt, take, capture, kill, attempt to take, capture, or kill, possess, offer for sale, sell, offer to barter, barter, offer to purchase, purchase, deliver for shipment, ship, export, import, cause to be shipped, exported, or imported, deliver for transportation, transport or cause to be transported, carry or cause to be carried, or receive for shipment, transportation, carriage, or export, any migratory bird, [or] any part, nest, or egg of any such bird . . . ” (16 U.S.C. 703(a)). Through issuance of permits for scientific collecting of migratory birds, the Service ensures that best practices are implemented for the careful capture and handling of eastern black rails during banding operations and other research activities. However, the December 22, 2017, Solicitor's Opinion, Opinion M-37050, concludes that consistent with the text, history, and purpose of the MBTA, the statute's prohibitions on pursuing, hunting, taking, capturing, killing, or attempting to do the same apply only to direct and affirmative actions that have as their purpose the taking or killing of migratory birds, their nests, or their eggs. Therefore, take of an eastern black rail, its chicks, or its eggs that is incidental to another lawful activity does not violate the MBTA. Furthermore, the MBTA does not address the major stressors affecting the eastern black rail, which include habitat alteration and sea level rise. Given that only intentional take is prohibited under the MBTA and the habitat-based stressors to the black rail are not regulated, this law does not provide sufficient substantive protections to the eastern black rail.

Section 404 of the Clean Water Act (33 U.S.C. 1251
et seq.
) and section 10 of the Rivers and Harbors Appropriation Act of 1899 (33 U.S.C. 403) are intended to protect jurisdictional wetlands from excavation and filling activities. The U.S. Army Corps of Engineers (USACE), in conjunction with the U.S. Environmental Protection Agency, administers permits that require avoidance, minimization, and compensation for projects affecting wetlands. Projects that cannot avoid impacts to wetlands must compensate for their impacts through a restoration enhancement or preservation action for the equivalent functional loss. Mitigation banks are often used, in which actions at a specific location compensate for impacts in a considerably wider service area. However, the wetland types affected are not always the same types that are restored or enhanced, and there is considerable uncertainty that current mitigation practices would support the presence of black rails.

State Protections

The black rail is listed as endangered under State law by seven States within the subspecies' range: Delaware, Illinois, Indiana, Maryland, New Jersey, New York, and Virginia. The species was formerly listed as endangered in Connecticut, but was considered extirpated during the last listing review based on extant data and was subsequently delisted. Protections are afforded to wildlife listed as either endangered or threatened by a State, but those protections vary by State. Although we have no information as to the effectiveness of these State regulations as they pertain to the conservation of the eastern black rail, one benefit of being State-listed is to bring heightened public awareness of the bird's existence.

In Delaware, the importation, transportation, possession, or sale of any endangered species or parts of endangered species is prohibited, except under license or permit (title 7 of the Delaware Code, sections 601-605). Illinois also prohibits the possession, take, transport, selling, and purchasing, or giving, of a listed species, and allows incidental taking only upon approval of a conservation plan (Illinois Compiled Statutes, chapter 520, sections 10/1-10/11). Indiana prohibits any form of possession of listed species, including taking, transporting, purchasing, or selling, except by permit (title 14 of the Indiana Code, article 22, chapter 34, sections 1-16 (I.C. 14-22-34-1 through 16)). Listed species may be removed, captured, or destroyed only if the species is causing property damage or is a danger to human health (I.C. 14-22-34-16).

Similar prohibitions on the possession of a listed species in any form, except by permit or license, are in effect in Maryland (Code of Maryland, Natural Resources, section 10-2A-01-09), New Jersey (title 23 of the New Jersey Statutes, sections 2A-1 to 2A-15), New York (New York's Environmental Conservation Law, article 11, title 5, section 11-0535; title 6 of the New York Codes, Rules and Regulations, chapter I, part 182, sections 182.1-182.16), and Virginia (Code of Virginia, title 29.1, section 29.1, sections 563-570 (29.1-563-570)). Violations of these statutes typically are considered misdemeanors, generally resulting in fines or forfeiture of the species or parts of the species and the equipment used to take the species. Some States also have provisions for nongame wildlife and habitat preservation programs (
e.g.,
title 7 of the Delaware Code, sections 201-204; Code of Maryland, Natural Resources, section 1-705). For example, in Maryland, the State Chesapeake Bay and Endangered Species Fund (Code of Maryland, Natural Resources, section 1-705) provides funds to promote the conservation, propagation, and habitat protection of nongame, threatened, or endangered species.

Black rail is listed as a “species in need of conservation” in Kansas, which requires conservation measures to attempt to keep the species from becoming a State-listed endangered or threatened species (Kansas Department of Wildlife, Parks and Tourism 2018, unpaginated). Black rail also is listed as a species of “special concern” in North Carolina and requires monitoring (North Carolina Wildlife Resources Commission 2014, p. 6). The species is identified as a “species of greatest conservation need” in 19 State wildlife action plans as of 2015 (USGS 2017, unpaginated). However, no specific conservation measures for black rail are associated with these listings, and most are unlikely to address habitat alteration or sea level rise.

Other Conservation Efforts

The Atlantic Coast Joint Venture (ACJV) recently decided to focus efforts on coastal marsh habitat and adopted three flagship species, one being the

eastern black rail, to direct conservation attention in this habitat. As part of this initiative, the ACJV-led Black Rail Working Group (BLRA WG) has drafted population goals for the eastern black rail and is drafting a Black Rail Conservation Plan (ACJV BLRA WG 2018, 2019, entire). An initial workshop to start development of the Conservation Plan took place in October 2018. Workshop participants identified five highest priority strategies to conserve the species in the Atlantic Flyway: (1) Create new habitat, (2) promote improved impoundment management, (3) develop and promote black rail-friendly fire best management practices, (4) develop and promote black rail-friendly agricultural practices, and (5) develop a landowner assurances program (ACJV BLRA WG 2019, entire). The Conservation Plan is expected to be completed in 2020. ACJV staff are also in the early stages of coordinating several other black rail-specific projects, namely, a species distribution map and an adaptive management tool. In addition, staff are working with partners on a Salt Marsh Bird Conservation Plan, which identifies stressors to Atlantic Coast tidal marshes and the efforts needed to conserve these habitats to maintain bird populations (ACJV 2019, entire). A draft of the plan has been developed, and a final plan is expected late 2019.

The Gulf Coast Joint Venture (GCJV) has had the eastern black rail listed as a priority species since 2007 (GCJV 2005, unpaginated). As a priority species, the black rail is provided consideration during the review of North American Wetland Conservation grant applications (Vermillion 2018, pers. comm.). Although detailed planning for the eastern black rail is not yet complete, the subspecies is considered in coastal marsh habitat delivery efforts discussed by GCJV Initiative Teams. Eastern black rails are believed to benefit from a plethora of coastal marsh habitat delivery efforts of GCJV partners, including projects authorized under the North American Wetland Conservation Act (16 U.S.C. 4401
et seq.
), the Coastal Wetlands Planning, Protection and Restoration Act (16 U.S.C. 3951
et seq.
), and the Service's Coastal Program, as well as management actions on State and Federal refuges and wildlife management areas. Eastern black rails will benefit when projects conserve, enhance, or restore suitable wetland habitat and BMPs, such as the use of prescribed burns and brush-clearing activities, are employed to account for the subspecies.

In November 2016, the Texas Parks and Wildlife Department (TPWD), in partnership with the Texas Comptroller's Office, initiated the Texas Black Rail Working Group (Shackelford 2018, pers. comm.). The main purpose of the group is to provide a forum for collaboration between researchers and stakeholders to share information about what is known about the species, identify information needs, and support conservation actions. The group has held two in-person meetings thus far: January 10, 2017, and August 9-10, 2018, and produced two newsletters and a conservation planning report (Horndeski and Shackelford 2017, entire; Horndeski 2018a, 2018b, entire).

Future Scenarios

As discussed above, we define viability as the ability of a species to sustain populations in the wild over time. To help address uncertainty associated with the degree and extent of potential future stressors and their impacts on the eastern black rail's needs, we applied the 3Rs using five plausible future scenarios. We devised these five scenarios by identifying information on the primary stressors anticipated to affect the subspecies into the future: Habitat loss, sea level rise, groundwater loss, and incompatible land management practices. These scenarios represent a realistic range of plausible future scenarios for the eastern black rail.

We used the results of our occupancy model to create a dynamic site-occupancy, projection model that allowed us to explore future conditions under these scenarios for the Mid-Atlantic, Great Plains, Southeast Coastal Plain, and Southwest Coastal Plain analysis units. We did not project future scenarios for the New England, Appalachian, or Central Lowlands analysis units because, as discussed earlier in this document, we consider these analysis units to be currently effectively extirpated and do not anticipate that this situation will change in the future. Our projection model incorporated functions to account for changes in habitat condition (positive and negative) and habitat loss over time. The habitat loss function was a simple reduction in the total number of possible eastern black rail sites at each time step in the simulation by a randomly drawn percentage that was specified under different scenarios to represent habitat loss due to development or sea level rise. We used the change in “developed” land cover from the National Land Cover Database (Homer
et al.
2015, entire) to derive an annual rate of change in each region, and we used NOAA climate change and sea level rise projections to estimate probable coastal marsh habitat loss rates; storm surge was not modeled directly (Parris
et al.
2012, entire; Sweet
et al.
2017b, entire). In the Great Plains analysis unit, we used ground water loss rates, instead of sea level rise data, to represent permanent habitat loss in the region. The overall groundwater depletion rate was based on the average over 108 years (1900-2008) (Konikow 2013, entire).

Our five scenarios reflected differing levels of sea level rise and land management, and the combined effects of both. These future scenarios forecast site occupancy for the eastern black rail out to 2100, with time steps at 2043 and 2068 (25 and 50 years from present, respectively). Each scenario evaluates the response of the eastern black rail to changes in three primary risks we identified for the subspecies: Habitat loss, sea level rise, and land management (grazing, fire, and haying). The trends of urban development and agricultural development remain the same,
i.e.,
follow the current trend, for all five scenarios. We ran 5,000 replicates of the model for each scenario. For a detailed discussion of the projection model methodology and the five scenarios, please refer to the SSA report (Service 2019, entire).

The model predicted declines in all analysis units across all five plausible future scenarios. Specifically, they predicted a high probability of complete extinction for all four analysis units under all five scenarios by 2068. The model predicted that, depending on the scenario, the Southeast Coastal Plain and Mid-Atlantic Coastal Plain analysis units would reach complete extinction between 35 and 50 years from the present; the Great Plains analysis unit would reach complete extinction between 15 to 25 years from the present; and the Southwest Coastal Plain analysis unit would reach complete extinction between 45 to 50 years from the present. Most predicted occupancy declines were driven by habitat loss rates that were input into each scenario. The model results exhibited little sensitivity to changes in the habitat quality components in the simulations for the range of values that we explored. For a detailed discussion of the model results for the five scenarios, please refer to the SSA report (Service 2019, entire).

Under our future scenarios, the Mid-Atlantic Coastal Plain, Great Plains, Southwest Coastal Plain, and Southeast Coastal Plain analysis units generally exhibited a consistent downward trend in the proportion of sites remaining

occupied after the first approximately 25 years for all scenarios. Given that most of the predicted declines in eastern black rail occupancy were driven by habitat loss rates, and future projections of habitat loss are expected to continue and be exacerbated by sea level rise or groundwater loss, resiliency of the four remaining analysis units is expected to decline further. We expect all eastern black rail analysis units to have no resiliency by 2068, as all are likely to be extirpated by that time. We have no reason to expect the resiliency of eastern black rail outside the contiguous United States to improve in such a manner that will substantially contribute to its viability within the contiguous U.S. portion of the subspecies' range. Limited historical and current data, including nest records, indicate that resiliency outside of the contiguous United States will continue to be low into the future, or decline if habitat loss or other threats continue to impact these areas.

We evaluated representation by analyzing the latitudinal variability and habitat variability of the eastern black rail. Under our future scenarios, the Great Plains analysis unit is projected to be extinct within the next 15 to 25 years, which will result in the loss of that higher latitudinal representative unit for the subspecies. In addition, the three remaining analysis units (Mid-Atlantic Coastal Plain, Southwest Coastal Plain, and Southeast Coastal Plain) are predicted to decline and reach extinction within the next 50 years. Thus, the subspecies' representation will continue to decline.

The eastern black rail will have very limited redundancy in the future. The Great Plains analysis unit will likely be extirpated in 15 to 25 years, leading to further reduction in redundancy and resulting in only coastal populations of the eastern black rail remaining. Having only coastal analysis units remaining (and with even lower resiliency than at present) will further limit the ability of the eastern black rail to withstand catastrophic events, such as flooding from hurricanes and tropical storms.

Please refer to the SSA report (Service 2019, entire) for a more detailed discussion of our evaluation of the biological status of the eastern black rail, the influences that may affect its continued existence, and the modeling efforts undertaken to further inform our analysis.

Summary of Changes From the Proposed Rule

This final rule incorporates changes to our proposed rule based on the comments we received, as discussed below in the Summary of Comments and Recommendations. Based on these comments, we also incorporated as appropriate new information into our SSA report, including updated survey information from Colorado, North Carolina, and Georgia. Small, nonsubstantive changes and corrections were made throughout the document in response to comments. However, the information we received during the public comment period on the proposed rule did not change our determination that the eastern black rail is a threatened species. The information also did not cause us to revise our determination that designation of critical habitat for the eastern black rail is not prudent.

We received substantive comments on the proposed 4(d) rule and have made changes to this rule as a result of the public comments received. Below is a summary of substantive changes made to the final listing rule and 4(d) rule:

• Based on information received on South Dakota, we removed it from the list of States where eastern black rail is considered a vagrant.

• In the preamble to the 4(d) rule, we provided a description of “dense overhead cover” for the eastern black rail and identified three methods of assessing this cover.

• In the preamble to the 4(d) rule, we defined a “management boundary” to include individual landholdings, such as a National Wildlife Refuge boundary, or as being formed through landscape-level agreements across landholdings of different or contiguous ownerships.

• In the 4(d) rule and its preamble, we removed the seasonal restrictions and provided clarification on the BMPs identified under the fire management activities. Based on the comments received, we removed the prohibition of prescribed burn activities when these activities take place during the nesting, brooding, and post-breeding flightless molt period. We recognize the importance of using prescribed fire as a management tool for restoring and maintaining habitats on public and private lands and realize that, in order to meet specific management goals, flexibility is needed with regard to the timing of prescribed fire application. For example, a prescribed burn during the growing season may be necessary to target invasive vegetation. We also acknowledge that prescribed burns conducted at any time of the year that do not provide for escape routes and refugia may result in negative impacts to eastern black rails. Under the final 4(d) rule, incidental take of eastern black rails resulting from prescribed fires is prohibited unless BMPs that minimize negative effects of the prescribed burn on the eastern black rail are employed and a portion of occupied dense cover for the rail is maintained within management boundaries.

We received comments requesting that we provide more information or clarification on the BMPs to use when conducting prescribed burns in eastern black rail habitat. We received feedback on the BMPs from fire practitioners within the Service who have experience managing for prescribed fire within eastern black rail habitat. We determined that at least 50 percent of the eastern black rail habitat within the management boundary should provide dense overhead cover required by the species within one calendar year, and we revised the 4(d) preamble and rule accordingly.

In order to accommodate smaller landholdings, we are excepting landholdings smaller than 640 acres from maintaining 50 percent of eastern black rail habitat in any given calendar year, as we realize it could be challenging to manage for this percentage on small parcels of land. We clarified examples of tactics that can be used to provide unburned refugia and escape routes for the eastern black rail and identified that unburned refugia patches should be no smaller than 100 square feet.

• In the 4(d) preamble and rule, we clarified the exception for the haying, mowing, and other mechanical treatment activities as to existing infrastructure that may be included in the exception. We clarified that existing infrastructure includes existing firebreaks, roads, rights-of-way, levees, dikes, fence lines, airfields, and surface water irrigation infrastructure (
e.g.,
head gates, ditches, canals, water control structures and culverts).

• In the 4(d) preamble and rule, we added an exception for incidental take that results from mechanical treatment activities that are done during the nesting or brooding periods with the purpose of controlling woody encroachment or other invasive plant species to restore degraded habitat.

• In the 4(d) rule and preamble, we removed the reference to “intensive or heavy grazing” in the prohibition. Based on a review of public comments, the terms “light,” “moderate,” and “heavy” grazing caused confusion. Eastern black rails may be found in grazed areas as long as dense overhead cover remains to provide them with suitable habitat. Therefore, grazing densities should maintain the dense overhead cover required by the eastern black rail and allow for the long-term maintenance of habitat conditions required by the subspecies. Because eastern black rails

require this dense overhead cover year-round, and not just during the nesting, brood-rearing, or flightless molt period, we removed the seasonal restriction on grazing activities. The final 4(d) rule prohibits incidental take resulting from only those grazing activities on public lands, either individually or cumulatively with other land management activities, that do not maintain the dense overhead cover required by the subspecies in at least 50 percent of eastern black rail habitat.

• We added a prohibition to the 4(d) rule that prohibits incidental take of the eastern black rail that results from long-term or permanent conversion, fragmentation, and damage of persistent emergent wetland habitat and the contiguous wetland-upland transition zone to other habitat types or land uses. We received public comments requesting that we consider prohibiting activities, such as road construction, residential, commercial, and industrial development, commercial development, and oil and natural gas exploration and extraction, including seismic lines, as these may have negative impacts on the eastern black rail and its habitat. In our SSA report and proposed and final rule for the eastern black rail, we identified habitat loss and fragmentation as an ongoing and future threat to the subspecies. We agree that protecting the persistent emergent wetland habitat and contiguous wetland-upland transition zone is necessary and advisable for the conservation of the eastern black rail.

• We added an exception to the 4(d) rule for incidental take of eastern black rails that may result from prescribed burns, grazing activities, and mechanical treatment activities that take place in existing moist soil management units or prior converted croplands, such as impoundments for rice or other cereal grains. We received public comments requesting that we consider an exception for these types of units. Some individual managed wetland units have an established history of intensive vegetation and soil management, which may include burning during the growing season on an annual or nearly annual basis (
e.g.,
moist soil management). In contrast to emergent wetlands, these wetland units have established objectives to maintain unvegetated (
e.g.,
mudflat), sparsely vegetated, and/or primarily annual plant communities that may not provide vegetative cover during a substantial portion of the growing season.

• We added an exception to the 4(d) rule for incidental take that may result from efforts to control wildfires and an exception for incidental take resulting from the establishment of new firebreaks (for example, to protect wildlands or manmade infrastructure) and new fence lines. Both of these activities allow for management that will benefit the conservation of the eastern black rail and its habitat, as well as provide for public safety.

Summary of Comments and Recommendations

In the proposed rule published on October 9, 2018 (83 FR 50610), we requested that all interested parties submit written comments on the proposal by December 10, 2018. 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 comments was published in the USA Today on October 15, 2018. We did not receive any requests for a public hearing. All substantive information provided during the comment period has either been incorporated directly into the SSA report or this final determination or addressed below.

Peer Reviewer Comments

In accordance with our peer review policy published on July 1, 1994 (59 FR 34270), we solicited expert opinion from knowledgeable individuals with scientific expertise that included familiarity with the eastern black rail and its habitat, biological needs, and threats. During development of the SSA report, we reached out to 10 peer reviewers and received responses from 5. We reviewed all comments received from the peer reviewers for substantive issues and new information regarding the eastern black rail. All comments were incorporated into the SSA report prior to the proposed rule. The reviewers were generally supportive of our approach and made suggestions and comments that strengthened our analysis. Peer reviewer comments are addressed in the following summary and incorporated into the SSA report and this final rule as appropriate.

1.
Comment:
One peer reviewer suggested we include additional discussion on the functional aspects of slope and hydrology in our Habitat Description provided in the SSA report. The commenter stated that this section focused almost entirely on floristics and the section would benefit from more discussion of habitat structure.

Response:
The Habitat Description section describes the floristic communities associated with the presence of eastern black rails. These floristic communities have associated relationships with slope and hydrology, which may vary across the range of the species. We have updated the SSA to include more information on habitat structure, including slope and hydrology in eastern black rail habitat.

2.
Comment:
One peer reviewer requested that we add a summary of the information on the rapid declines of eastern black rail populations.

Response:
We have added this information to chapter 2 of the SSA report.

3.
Comment:
One peer reviewer requested that we add a figure to show the analysis units where the eastern black rail is considered extirpated.

Response:
We include a map in the SSA report that identifies the five analysis units. In the report's text, we identify the three analysis units that we consider to be effectively extirpated: New England, Appalachians, and Central Lowlands due to recent low numbers of detections and documented extirpations from previously occupied areas.

4.
Comment:
One peer reviewer requested that we provide a `minimum number' of eastern black rails in the analysis units. This reviewer stated that it would highlight how dire the situation is for this subspecies across all of its range. The reviewer noted that the subspecies has been extirpated from a large percentage of its range and has declined by over 90 percent in areas that were former strongholds.

Response:
We added a table to the SSA report that provides population estimates (reported as the number of breeding pairs) for eastern black rail in the northeast and southeast United States. We also provided additional discussion in chapter 2 of the SSA report on population declines.

5.
Comment:
One peer reviewer requested that we provide a more detailed description of the projection model and the data that drive the model.

Response:
We expanded the discussion in the SSA report and the Appendices.

6.
Comment:
One peer reviewer commented that the current condition analysis underestimated the range of habitat the eastern black rail has used and will accept. According to the reviewer, eastern black rails have historically nested in a range of situations along the coast and inland that are connected by some physical characteristics. The peer reviewer stated that most of the recent survey data came from coastal marshes, which represents a subset of what the species has used, and so may underestimate resiliency.

Response:
We respectfully disagree with this comment. The eastern black

rail has a very small home range. There is currently substantial habitat available that is not being used at locations where we know the bird is present. The fact that habitats are not being fully used indicates that there is a lack of “resiliency” for the population under current conditions. The limiting factor does not appear to be habitat. Further, our current condition analysis was informed by our analysis units, which were developed using data from South Carolina, Florida, Texas, and Kansas.

7.
Comment:
One peer reviewer commented that the eastern black rail has historically shown a pattern of colonization that puts it in the pioneer category, that is, it can take advantage of habitat patches that are ephemeral. While the eastern black rail may require a narrow niche in terms of vegetation structure and hydrology, it does appear capable of finding locations that have these preferred habitat characteristics.

Response:
We added a discussion of this adaptive potential into the SSA report in chapter 4.

8.
Comment:
One peer reviewer noted that some eastern black rails are migratory, but acknowledged that this cannot really be incorporated into a dynamic occupancy model. However, the reviewer suggested we note this in our discussion of the model.

Response:
We agree that some eastern black rails are migratory. However, we note that we are trying to understand how populations might change and it is likely that individual birds would breed in the same place. Eastern black rails that reside in northern latitudes migrate and overwinter at locations further south (Butler 2017). Since little is known about migration behavior and site fidelity of migrants, migration is not considered a factor in these analyses.

9.
Comment:
One peer reviewer asked why we used slope as a covariate in the development of our analysis units and whether we considered using elevation.

Response:
The variation in elevation was very small, and we did not have enough information on elevation to find a relationship. In essence, the variables were colinear and elevation varied by little if at all. Slope, however, while colinear with elevation, had a wide range of values. In the end, elevation was not a useful variable for the analysis.

10.
Comment:
One peer reviewer identified a dataset from North Carolina that provides data on eastern black rails from the historical `high use' part of the State, as well as two datasets from Maryland and New Jersey, and suggested we consider incorporating these data into our dynamic occupancy model to inform the analysis of the Mid-Atlantic analysis unit. A second peer reviewer also identified the Maryland dataset and asked why these data were not incorporated into the dynamic occupancy model.

Response:
Our occupancy analyses used to evaluate current condition required at least two consecutive years of survey data; therefore, the Maryland survey data were not used in our model, as these data were not collected in successive years. However, we used the Maryland dataset to calculate psi (detection) and occupancy for a single season and incorporated this information into our SSA report. These data were from the same sites surveyed three times over ~25 years (Brinker 2014, unpublished data). The Maryland sites saw a decline in estimated occupancy from ~0.25 to 0.03, giving credence to the inference that occupancy has declined for eastern black rails in the Mid-Atlantic Coastal Plain analysis unit. Similarly, the New Jersey and North Carolina datasets referred to by the commenter did not have successive years of surveys; however, the contemporary State data were used in the development of our analysis units (the data were insufficient for the dynamic occupancy analysis).

11.
Comment:
One peer reviewer noted that when developing the covariate analysis we do not have the high-resolution data, such as water depth data that has a resolution of 1 centimeter or vegetation data associated with the hydrology, that would provide the resolution really needed for this species and produce meaningful insights.

Response:
We did not get these types of data (
e.g.,
water depth or vegetation) from available reports. In fact, we often had to use remotely-sensed information to help inform the model. The covariates might be considered coarse given that these variables had to be remotely sensed; however, these data were not collected during the studies across all sites, so this was the best available information. It should be noted that water depth is weather dependent and can change at any time, so we do not believe that a more resolute data set of ±1 centimeter would be meaningful. It is reasonable to desire higher resolution,
i.e.,
vegetation, in order to enhance our understanding; however, we conclude that the results are meaningful. We do note in our current condition occupancy analysis that the occupancy data indicated only the null model (
i.e.,
a model with no covariates) or a simple, year-specific model was the best model or equally as good. However, the occupancy and extinction risk analyses were useful, even if we cannot predict at a local scale why any individual site might disappear.

12.
Comment:
One peer reviewer asked how the occupancy modeling results were influenced by the selection of the survey data inputted into the model. For example, how would the results differ if survey points were used from areas that lacked black rails as opposed to locations where black rails are known to occur?

Response:
Our assessment of current condition and future condition is based on the occupancy, colonization, and extirpation estimates from the repeated survey data, which rely on adequate site selection for black rail surveys in order for the results to be useful in making inferences about current and future population status. Improper site selection could introduce negative bias on model estimates (
i.e.,
decrease occupancy, decrease colonization) and thus lead to pessimistic assessment of current and future status. However, these survey points were specifically selected to target black rail habitat and sites where black rails had been previously observed. Surveyors used the best available information on black rail habitat preferences and set their survey points accordingly.

13.
Comment:
One peer reviewer noted that the datasets used in the dynamic occupancy model were based on point-count networks. As noted in the SSA report, the availability of such surveys is limited for the eastern black rail. The peer reviewer suggests an occupancy analysis based on marsh patches, rather than point counts, as it would allow for longer time series and a greater geographic area for analysis.

Response:
In order to undertake an occupancy analysis based on marsh patches, we would need to come up with a definition of what constituted a patch, and these would likely not be equal in size across the range of the bird. Points have a distinct spatial definition that is repeatable. Additionally, we followed the National Marshbird Monitoring Plan, which uses a point-count approach. While developing an analysis based on marsh patches may allow for the use of longer time series and larger geographic areas, there would be an associated incorporation of error through defining marsh patches and extrapolation. The approach used directly relies on survey results, and, given the limited number of observations, using patches would have resulted in more temporal samples but fewer point samples.

14.
Comment:
One peer reviewer commented that land cover, vegetation type, land-use/modification, extent of

hydrologic disruption, or percentage change in wetland area may be more suitable variables to use in the projection model to predict extinction and colonization probability of eastern black rails.

Response:
Other analysis already available showed that temperature was an important covariate. We included temperature to reflect those existing analyses. Precipitation was used because it was colinear with wetland water depth and wetland spatial extent for this species. Some of these variables were used in the projection modeling, as well. Assumptions of both models were clearly articulated in the SSA report.

15.
Comment:
One peer reviewer stated that the definition of a site is missing. This peer reviewer commented that the site-occupancy projection model does not consider site isolation, which limits eastern black rail colonization, and site size, which is a factor related to extinction.

Response:
The definition of “site” was added to both the data analysis portion of the Appendix and to the simulation modeling portion (in the SSA report). The projection model was not spatially explicit; adding site isolation could potentially increase extinction risk at a local site and reduce colonization.

16.
Comment:
One peer reviewer requested clarification on how occupancy and resilience were related and if we were equating occupancy with resiliency.

Response:
Given data availability, eastern black rail resiliency was estimated using the probability of occupancy at the analysis unit-level. Resiliency describes the ability of a population to withstand stochastic disturbance. Stochastic events are those arising from random factors such as weather, flooding, or fire. Resiliency is positively related to population size and growth rate and may be influenced by connectivity among populations. Generally speaking, populations need enough individuals, within habitat patches of adequate area and quality, to maintain survival and reproduction in spite of disturbance. Resiliency is measured using metrics that describe analysis unit condition and habitat; in the case of the eastern black rail, we used occupancy within the analysis units to assess resiliency.

17.
Comment:
One peer reviewer asked what would happen to our assessment of viability if our assessment had included types of habitat that eastern black rails can use that have not been sampled, such as the types of sites where black rails are found in California or the Front Range of Colorado.

Response:
The projection models are entirely dependent on the data used to estimate occupancy and extinction dynamics. Our assessment included habitat types such as those found in California or Colorado (
i.e.,
inland palustrine marshes). The values we used to project future conditions used regional rates of wetland loss where available for emergent wetlands and did not distinguish between emergent wetland types.

Federal Agency Comments

18.
Comment:
A Federal agency recommended including the following on the list of mowing and mechanical treatment activity exemptions in the 4(d) rule as they are unlikely to occur in suitable eastern black rail habitat: Permanently flooded areas/open water exceeding [
e.g.,
less than 6 cm]; paved areas; cropland (
i.e.,
areas planted to annual row crops, such as corn and soybeans including hay in rotation); forest; and pasture or areas mowed, hayed, or grazed too frequently or intensively to allow development of dense emergent wetland vegetation.

Response:
Incidental take associated with activities in habitats not suitable for the eastern black rail is not prohibited. While there is a chance that an individual eastern black rail may be present in such non-suitable habitats, it is the intent of this rule to focus the prohibitions in areas where eastern black rail occupancy is likely and where eastern black rails are present. Therefore, we are not adding a list of unsuitable habitats to the list of exceptions for haying, mowing, and other mechanical treatment activities because it is not necessary.

19.
Comment:
A Federal agency requested that we provide, in the exemptions section of the 4(d) rule, a list of land uses or habitat types where the eastern black rail is likely to be present.

Response:
Section 2.4.2 of the SSA report describes the vegetation associations used by the eastern black rail. For more specific information, we encourage interested parties to contact the local Service field office.

20.
Comment:
One Federal agency commented that BMPs should aim to discourage eastern black rail occupancy, as opposed to limiting exemptions when infrastructure and human health or safety is the sole concern.

Response:
We did not include measures to discourage eastern black rail occupancy, as these types of activities would not promote conservation of the species.

21.
Comment:
A Federal agency asked that the Service provide seasonal windows corresponding to the critical time periods during which activities are prohibited under the 4(d) rule.

Response:
We revised the 4(d) rule to allow the use of prescribed fire and grazing during any time of year. Incidental take resulting from haying, mowing and other mechanical treatment activities is prohibited, with exceptions, in persistent emergent wetlands during the nesting and brood-rearing periods. We have provided additional information on critical time periods for the eastern black rail in the SSA report (Service 2019, entire).

22.
Comment:
One Federal agency commented that a blanket restriction on burning during the natural fire season in South Florida may reduce habitat suitability for other threatened and endangered species. One commenter recommended that the 4(d) rule exempt take of birds in South Florida that results from all prescribed fire being undertaken for all natural resource management, in recognition of the fact that fire is a natural and integral component of managing the ecosystems upon which black rails and countless other species occupy.

Response:
Under the final 4(d) rule, incidental take of eastern black rails due to prescribed fire is prohibited unless BMPs that minimize negative effects of the prescribed burn on the eastern black rail are employed. If these practices are followed, prescribed burning is permissible year-round under the 4(d) rule. This is similar to recovery efforts for fire-adapted threatened and endangered species such as the Florida grasshopper sparrow, which involve precautions designed to limit mortality of eggs and chicks due to prescribed fire activities. The identified practices are necessary and advisable for the conservation of the eastern black rail and, if followed, should minimize take of the eastern black rail and allow for population growth and maintenance. The 4(d) rule provides land managers the flexibility to address habitat management goals while maintaining suitable habitat for eastern black rails.

23.
Comment:
One Federal agency commented that we should focus on the vegetative conditions desired when using prescribed fire for the eastern black rail rather than the methods and techniques used.

Response:
Most grassland and marshland habitats are maintained through a disturbance regime with natural and anthropogenic fires being a primary disturbance agent. Survey results and field observations indicate that habitat is currently available that would support the eastern black rail but is unoccupied. Therefore, measures that

minimize mortality and improve survival are important if populations are expected to grow and spread to available habitats. For these reasons, we determined that the 4(d) rule must address methods and techniques used, as we find that this is necessary and advisable to provide for the conservation of the eastern black rail. The preamble of the 4(d) rule does discuss the dense overhead cover required by the eastern black rail and provides three examples of how to measure this cover.

24.
Comment:
One Federal agency and one State requested that activities to control nuisance and/or invasive wildlife,
e.g.,
hazing or pyrotechnics at airports, aerial shooting of feral swine, beaver and nutria trapping, and removal of beaver dams, be added to the exceptions from prohibitions.

Response:
Incidental take of eastern black rails that results from activities to control nuisance and/or invasive wildlife is not prohibited by the 4(d) rule and, therefore, does not need to be listed under the exceptions from prohibitions. These activities include pyrotechnics at airports, aerial shooting of feral swine, beaver and nutria trapping, and removal of beaver dams.

State Comments

Listing

25.
Comment:
Three States and two public commenters expressed concerns regarding the limited information surrounding the species' and management needs overall, as well as in the SSA analysis and the listing and 4(d) rules. Commenters either requested that listing of the eastern black rail be delayed, or stated that a listing determination could not be made until more data were collected on the species.

Response:
We are required to make our determination based on the best scientific and commercial data available at the time of our rulemaking, except in cases where the Secretary finds that there is substantial disagreement regarding the sufficiency or accuracy of the available data relevant to the determination. In such a case, under section 4(b)(6)(B)(i) of the Act, the Secretary may extend the 1-year period to make a final determination by up to 6 months for the purposes of soliciting additional data. In this case, we did not extend our final determination on the listing status of the eastern black rail because we determined that there was no substantial disagreement regarding the sufficiency or accuracy of the available threats information. We considered the best scientific and commercial data available regarding the eastern black rail to evaluate its potential status under the Act. We solicited peer review of our evaluation of the available data, and our peer reviewers supported our analysis. That said, science is a cumulative process, and the body of knowledge is ever-growing. In light of this, the Service will always take new research into consideration. If such research supports amendment or revision of this rule in the future, the Service will modify the rule consistent with the Act.

26.
Comment:
One State stated that there is little evidence to suggest eastern black rails can be reliably found at any location in Kansas other than Quivira National Wildlife Refuge. Another commenter stated that there is little evidence to suggest eastern black rails can be reliably found at Cheyenne Bottoms. Both commenters requested that the final rule reflect this information.

Response:
We reviewed the best available information on the occurrences of eastern black rail in Kansas. This information indicates that eight counties have confirmed breeding records in Kansas, but Quivira National Wildlife Refuge is the only known site with consistent or regular breeding activities (Thompson
et al.
2011, p. 123). We have revised the SSA report accordingly.

27.
Comment:
One State commenter stated that the single accepted record for South Dakota was rejected by the South Dakota Rare Bird Records Committee; therefore, no verified occurrence records of the subspecies occur in South Dakota.

Response:
The reference to South Dakota has been removed from the final listing rule and from the corresponding sentence in the SSA.

28.
Comment:
One State and one other commenter stated that eastern black rail estimates for Texas are underestimates and public and private lands have ample area for eastern black rail. One commenter stated that the listing of the eastern black rail should be limited to the portions of the range where decline has been documented. This commenter stated that the species is declining in other parts of the range but is not imperiled on the Texas Gulf Coast. One commenter stated that the SSA used only Watts' data on subspecies abundance in Texas and excluded that provided by Tolliver (2017). This commenter also stated that eastern black rail estimates for Texas are underestimates, commenting that because the Texas coast is largely privately owned with sites managed similarly as described in Tolliver (2017), it is safe to assume that the Texas population of eastern black rails is higher than suggested in the SSA report.

Response:
We analyzed occurrence records from Watts (2016), Smith-Patten and Patten (2012), and eBird, as well as from formal black rail surveys (
e.g.,
Tolliver 2017) in the SSA. The best available science as detailed in the SSA report documents 300-5,830 black rails known to exist along the Texas Gulf Coast (Tolliver
et al.
2017). These estimates were made prior to Hurricane Harvey, which flooded vast areas of Texas coastal marshes for several weeks. Accordingly, we recognize that the estimates in Tolliver
et al.
(2017) may overestimate the current numbers of eastern black rails on the Texas coast in the protected areas that were surveyed. However, the occupancy rates provided by Tolliver
et al.
(2019) were obtained from sites known to be dependable for the species and data were collected by trained observers. The low occupancy rates indicate that not all available habitat is being used because so few individuals remain; these populations are not at density-dependent levels,
i.e.,
the habitat is not full or at carrying capacity. Note that the Tolliver
et al.
(2017) report stated that, while the researchers did extrapolate abundance of birds at survey points to perceived habitat available within the study sites, they cautioned against viewing this information as hard estimates of population size due to inherent flaws in making broad-scale extrapolations of this type. Site occupancy modeling detailed in the SSA projects that this species will disappear without human intervention. While this species may exist at undocumented locations on the Texas Gulf Coast, we have received no records of large numbers of previously undocumented eastern black rails for this portion of the range and have no scientific basis for assuming that they are present. Further, while there may be habitat on private lands outside of conservation lands that do support black rails, we have no data to indicate that the amount of suitable habitat on private lands is significant, nor was data that supports this claim provided during the public comment period.

It would not be appropriate to assume that the public lands evaluated by Tolliver 2017 and private lands are managed the same and that the population estimates for Texas are actually higher than what is suggested in the SSA report. While habitat can be assessed through remote sensing methods, its quality is extremely difficult to assess using this method. The quality of the habitat (dense overhead herbaceous cover) is necessary to support eastern black rail occupancy.

No data support the assumption that areas outside of those studied by Tolliver 2017 (and Tolliver
et al.
2017 and 2019) support similar numbers of rails.

Decisions under the Act cannot be made on a State-by-State basis, but at the species, subspecies, or distinct population segment (DPS) level. For the eastern black rail, we have determined that the subspecies warrants listing as a threatened species throughout its range based on current threats and how those threats are likely to impact the subspecies into the future.

29.
Comment:
Several States and other commenters stated that the eastern black rail geographic range should include only areas where the species occurs regularly (annually or near annually), and should avoid identifying jurisdictions (
e.g.,
States) where eastern black rail is considered to be a vagrant. One State noted that the Service does not explain or provide justification as to why it accepted several additional reports as “credible” in Nebraska even though previous authors (Bray
et al.
1986, Sharpe
et al.
2001, Smith-Patten and Patten 2012, Silcock and Jorgensen 2018) and the Nebraska Ornithological Union Records Committee rejected most of these records and deemed them unacceptable, and that only records accepted by the State rare bird committee should be used. The State commenters specifically requested removal of entire States or large portions of their States, and requested that listing of the eastern black rail not confer any requirements for any Federal or State agency or private landowners in those areas. Commenters also recommended that the final rule rely only on accepted and verified records of eastern black rail when determining the species' range, in particular for migratory birds that breed in the interior United States.

Response:
In both the proposed and final rules, we have defined the eastern black rail'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. We recognize that Nebraska has limited detections of eastern black rails and the small likelihood that Nebraska holds any breeding populations. 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 DPS). A species' or subspecies' range is typically described at the State or country scale.

We defined the eastern black rail's range based on the data from reliable published scientific literature, submitted manuscripts, species' experts, and occurrence data. Range descriptions do 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 or maps of the eastern black rail's range, the subspecies would be protected under the Act wherever it may be found, for as long as it remains listed. Further, the Act protects individuals of the species wherever they occur, regardless if they are considered vagrant in their occurrence. Conversely, if the species is not present in areas within the range states, no protections or restrictions would apply to those areas.

30.
Comment:
One State commented that invasive species such as nonnative
Phragmites
and nutria should be identified as threats to the eastern black rail.

Response:
Our SSA report for the eastern black rail discusses the impacts of invasive species, including nonnative plants and nutria, on the eastern black rail. See Service 2019 (chapter 3).

31.
Comment:
One State commented that human disturbance is not a significant threat in North Carolina due to the remote nature of the habitat and the bird's nocturnal habits.

Response:
The comment is noted; however, the evaluation of threats for this subspecies were done both at the analysis unit and the range-wide scale and reflect evidence that human disturbance can and does impact eastern black rail.

32.
Comment:
One State commented that the Service should consider the use of DPSs given the broad range of the eastern black rail and differences in potential threats, habitat types, and life cycles (migratory versus non-migratory) to those populations.

Response:
The petition to list the eastern black rail requested that we consider whether listing is warranted for the species. In conducting status reviews, we generally follow a step-wise process where we begin with a range-wide evaluation, and only consider the status of other listable entities if the species does not warrant listing range-wide. Furthermore, the Service is to exercise its authority with regard to DPSs “sparingly and only when the biological evidence indicates that such action is warranted” (Senate Report 151, 96th Congress, 1st Session). For the eastern black rail, we have determined that the subspecies warrants listing as a threatened species throughout its range, so there was no need to identify or list a DPS.

Species Status Assessment (SSA)

33.
Comment:
Two States and several public commenters provided additional information concerning the historical and current status, range, distribution, and population size of the eastern black rail within the contiguous United States.

Response:
In our SSA report, we have updated the Historical and Current Range and Distribution section to reflect additional information for Colorado, Delaware, Georgia, Maryland, and North Carolina.

34.
Comment:
Two States and one public commenter stated that there is a scarcity of data used for the Great Plains Analysis Unit in the SSA. One commenter stated that using general marshbird survey data from Kansas is not appropriate.

Response:
The best available scientific and commercial information for this species was used to inform extinction probabilities. Data from black rail-specific surveys were not available for the Great Plains Analysis Unit; therefore, the general marshbird survey data from Kansas, which include eastern black rail detections, represent the best available scientific information. The general marshbird dataset was sufficient for occupancy modeling to be completed for this analysis unit. Further, the occupancy probabilities appeared to be well estimated since the standard error estimates for most parameters were less than the estimated mean (
i.e.,
the coefficient of variations are less than 1.0).

35.
Comment:
Two States encouraged the Service to apply more critical scrutiny to historical observations of eastern black rail that are used in the SSA, especially those from the interior portion of the range, and only include verified and substantial observations.

Response:
The SSA report summarizes several past assessments, including Watts (2016) and Smith-Patten and Patten (2012), and identifies how those reports classified the eastern black rail. In collecting data points from different sources to assess the eastern black rail across its entire contiguous United States range, we went through a rigorous process to ensure validity of these data. We assessed datasets using different criteria for the analysis unit and occupancy modeling (occupancy modeling is described in section 4.2 of the SSA report). Latitude and longitude data provided by each research group and State wildlife a

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2020-19661. Public record. Not legal advice.