Letcher County FEIS Appendix H (Part 3) - USFWS Endangered Species Act Consultation (2017).pdf

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TABLE OF CONTENTS

EXECUTIVE SUMMARY ......................................................................................................... iv

CONSULTATION HISTORY.................................................................................................. viii

BIOLOGICAL OPINION

1. PROPOSED ACTION

Action Area ..................................................................................................................... 3 1.1.

Land Acquisition ............................................................................................................. 6 1.2.

Compensatory Mitigation ............................................................................................... 6 1.3.

Construction Activities .................................................................................................... 6 1.4.

Operational Activities ..................................................................................................... 7 1.5.

Interrelated and Interdependent Actions ........................................................................ 7 1.6.

2. INDIANA BAT

Description of the Indiana Bat ........................................................................................ 8 2.1.

Life Cycle of the Indiana Bat .......................................................................................... 8 2.2.

Habitat Characteristics and Use of the Indiana Bat .................................................... 11 2.3.

Status and Distribution of the Indiana Bat ................................................................... 14 2.4.

Stressors to the Indiana Bat .......................................................................................... 17 2.5.

Environmental Baseline for the Indiana Bat ................................................................ 21 2.6.

Effects of the Action on the Indiana Bat ....................................................................... 28 2.7.

Conclusion for the Indiana Bat ..................................................................................... 51 2.8.

3. NORTHERN LONG-EARED BAT

Description of the Northern Long-eared Bat ................................................................ 54 3.1.

Life Cycle of the Northern Long-eared Bat .................................................................. 54 3.2.

Habitat Characteristics and Use of the Northern Long-eared Bat............................... 56 3.3.

Status and Distribution of the Northern Long-eared Bat ............................................. 58 3.4.

Stressors to the Northern Long-eared Bat .................................................................... 60 3.5.

Environmental Baseline for the Northern Long-eared Bat........................................... 63 3.6.

Effects of the Action on the Northern Long-eared Bat ................................................. 68 3.7.

Conclusion for the Northern Long-eared Bat ............................................................... 90 3.8.

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4. INCIDENTAL TAKE STATEMENT

Amount or Extent of Take ............................................................................................. 94 4.1.

Reasonable and Prudent Measures .............................................................................. 95 4.2.

Terms and Conditions ................................................................................................... 96 4.3.

Monitoring and Reporting Requirements ..................................................................... 964.4.

5. CONSERVATION RECOMMENDATIONS

6. REINITIATION NOTICE

LITERATURE CITED

APPENDIX A – Email Addendum to BA

APPENDIX B – Additional Figures and Tables iv

EXECUTIVE SUMMARY

This Endangered Species Act (ESA) Biological Opinion (BO) of the U.S. Fish and Wildlife Service (Service) addresses the Federal Bureau of Prisons’ (Bureau) proposed construction and operation of a U.S. Penitentiary and Federal Prison Camp on an approximately 231.1-hectare (570-acre) property near Roxana, in Letcher County, Kentucky (the Action). The Bureau determined that the Action is likely to adversely affect the Indiana bat (Myotis sodalis) and the northern long-eared bat (Myotis septentrionalis) and requested formal consultation with the Service. The BO concludes that the Action is not likely to jeopardize the continued existence of these species, and is not likely to destroy or adversely modify designated critical habitat. This conclusion fulfills the requirements applicable to the Action for completing consultation under §7(a)(2) of the ESA of 1973, as amended, with respect to these species.

The Bureau also determined that the Action is not likely to adversely affect the gray bat (Myotis grisescens) and requested Service concurrence. The Service concurs with these findings.

We provided our basis for this concurrence by letter dated May 10, 2017. This concurrence fulfills the requirements applicable to the Action for completing consultation with respect to this species. The Bureau also determined that the Action would have “no effect” on the Kentucky arrow darter (Etheostoma sagitta spilotum). Federal action agencies do not need concurrence from the Service for “no effect” determinations.

The Action Area is defined as the area within a 4.0 km (2.5 mi) radius from the approximate center of the proposed facilities. The Action Area includes the 231.1-hectare (570-acre) property proposed for the facility. Of these 231.1 hectares (570 acres), 73 hectares (180.5 acres) are within the clearing and grading limits. The remaining 157.6 hectares (389.5 acres) will remain undisturbed. The Action includes constructing a U.S. Penitentiary, a Federal Prison Camp, a central utility plant, a training center with an outdoor firing range and staff training building, a warehouse, a garage/landscape building, access roads, and parking areas. Construction of the facility would take place during a 4-5 year time frame. Once constructed, the facility would continue in operation indefinitely.

As part of the Action, the Bureau proposes to implement the following conservation measures to minimize the effects of the take:

Retain 157.6 hectares (389.5 acres), 95.4 forested hectares (235.8 acres), of the 231.1-hectare (570-acre) property as undisturbed buffer to the facility.

Contribute to the Imperiled Bat Conservation Fund (IBCF) as compensatory mitigation for the adverse effects on Indiana bats and northern long-eared bats that will result from the permanent loss and modification of forested habitat.

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Develop an erosion and sediment control plan detailing best management practices (BMPs) to be implemented during construction and submit the plan to the Kentucky Division of Water for approval.

Implement the approved erosion and sediment control plan.

Avoid tree removal during the months of June and July.

Avoid blasting from November 15 through March 31.

Conduct all construction activities occurring from April 15 – October 31 in suitable Indiana bat and/or northern long-eared bat habitat during daylight hours.

Require contractors to inspect vehicles and equipment to ensure that visible plant and seed material has been removed prior to entering the construction area.

Aim construction lighting toward construction and away from forested habitat.

Install lights exterior lights with full cutoff light fixtures (which do not emit direct uplight) for operational activities at the facility.

Fence a feature that was identified as a potential hibernaculum and install warning signs around the area to prevent direct disturbance.

Indiana bats and northern long-eared bats hibernate in caves and cave-like structures during the winter. After emergence, they forage around hibernacula for a few days to weeks before migrating to a summer area. During the summer they roost in trees during the day and forage on insects at night. Indiana bats often forage along riparian corridors and forested edges, and northern long-eared bats typically use forest interiors. Reproductive females roost in maternity colonies. Both species show high site fidelity to summer habitat. Non-volant pups are present in June and July. In the fall, individuals swarm around hibernacula for several weeks where they mate and build up fat reserves for hibernation.

The Action Area is within the 16.1 km (10-mile) swarming range of the Line Fork Cave system that is used by Indiana bats during fall swarming. There are no documented hibernacula in the Action Area. Field assessments revealed one feature, a crack in a small rock shelter, which could potentially provide winter habitat for Indiana bats and northern long-eared bats. This feature was not surveyed for presence of the species and, for the purposes of our evaluation, we are assuming it is used by Indiana bats and northern long-eared bats as a hibernaculum. The surrounding properties could not be assessed in the field; we are assuming that there is one additional hibernaculum located just off of the property.

The Action Area contains forested habitat suitable for Indiana bats and northern long-eared bats as roosting, foraging, and commuting habitat. This includes 48.8 hectares (120.6 acres) of forested habitat at the site of the proposed facility that will be removed by the Action. The nearest known hibernacula are the Line Fork complex approximately 8.9 km (5.5 mi) to the southeast. In the absence of recent summer surveys for the species, we are assuming that there is vi an Indiana bat maternity colony and male Indiana bats roosting near the center of the proposed clearing and grading limits and that these individuals use habitat in the clearing and grading limits for roosting, foraging, and commuting. There are six summer records of northern long-eared bats within 4.8 km (3-mi) of the proposed clearing and grading limits. We are assuming that each of these represents a maternity colony and male bats, and that these individuals use habitat in the clearing and grading limits for roosting, foraging, and commuting.

Based on our assumptions and our knowledge of the biology of the species we assume that the following numbers of individual Indiana bats and northern long-eared bats are using the Action Area during the specified timeframes:

Indiana bats Northern long-eared bats Hibernation (Nov. 15 – Mar. 31)

24 10

Spring Staging (Apr. 1 – May 14)

24 10

Summer (Apr. 1 – Aug. 15)

270 810

Fall Swarming (Aug. 16 – Nov. 14)

148 10

We identified several stressors resulting from the proposed Action and evaluated their effects on the Indiana bat and the northern long-eared bat. We concluded that the following stressors would have insignificant and/or discountable effects on the species: stream sedimentation, hazardous material spills during construction and/or operation of the facility, noise/vibrations from blasting, noise/vibrations from other construction activities, increased human presence during construction and during facility operation, traffic, and collisions with vehicles. We identified and evaluated several stressors that we concluded will have significant adverse effects on the Indiana bat and the northern long-eared bat: strikes from equipment or trees, removal of occupied roost trees, loss of forested habitat on the landscape, night lighting during construction and facility operation, and noise from small arms fire.

The duration of the effects from the specific stressors will vary. The effects from strikes from equipment or trees, removal of occupied roost trees, and night lighting during construction, would be temporary during the 4-5 year construction period and the following year. The loss of forested habitat on the landscape and night lighting during facility operation would be permanent, but we expect Indiana bats and northern long-eared bats to adapt their behavior to the altered landscape. The effects of noise from small arms fire will occur intermittently in perpetuity.

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We assume that, as a result of the Action, some of the Indiana bats and northern long-eared bats will experience harm, some will experience harassment, and some will experience both harm and harassment. We cannot determine how many will experience each of these effects. We expect most of the effects to be in the form of harassment and not result in mortality. We estimate that the Action would result in the take of 418 Indiana bats and 810 northern long-eared bats.

The BO includes an Incidental Take Statement that requires the Bureau to implement reasonable and prudent measures that the Service considers necessary or appropriate to minimize the impacts of anticipated taking on the listed species. Incidental taking of listed species that is in compliance with the terms and conditions of this statement is exempted from the prohibitions against taking under the ESA.

In the Conservation Recommendations section, the BO outlines voluntary actions that are relevant to the conservation of the listed species addressed in this BO and are consistent with the authorities of the Bureau.

Reinitiating consultation is required if the Bureau retains discretionary involvement or control over the Action (or is authorized by law) when:

(a) the amount or extent of incidental take is exceeded;

(b) new information reveals that the Action may affect listed species or designated critical habitat in a manner or to an extent not considered in this BO;

(c) the Action is modified in a manner that causes effects to listed species or designated critical habitat not considered in this BO; or

(d) a new species is listed or critical habitat designated that the Action may affect.

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CONSULTATION HISTORY

This section lists key events and correspondence during consultation. A complete administrative record of this consultation is on file at the U.S. Fish and Wildlife Service’s Kentucky Field Office (KFO).

February 28, 2017 The Bureau of Prisons (Bureau) provided the KFO with a draft Biological Assessment (BA).

March 21, 2017 The KFO provided the Bureau with comments on the draft BA.

May 1, 2017 The Bureau requested initiation of formal consultation with the Service and provided a final BA.

May 10, 2017 The KFO notified the Bureau that the submitted BA contained sufficient information to initiate formal consultation, and formal consultation was initiated.

June 5, 2017 The Bureau sent an email to the Service regarding the timing of the mitigation contribution (Appendix A).

July 5, 2017 The KFO provided the Bureau with a draft Biological Opinion (BO).

July 21, 2017 The Bureau provided the KFO with comments on the draft BO.

July 27, 2017 The KFO issued the final BO.

BIOLOGICAL OPINION

A Biological Opinion (BO) is the document that states the opinion of the U.S. Fish and Wildlife Service (Service) under the Endangered Species Act of 1973, as amended (ESA), as to whether a Federal action is likely to:

a) jeopardize the continued existence of species listed as endangered or threatened, or

b) result in the destruction or adverse modification of designated critical habitat.

The Federal action addressed in this BO is the U.S. Department of Justice Federal Bureau of Prison’s (Bureau) proposed construction and operation of a U.S. Penitentiary (USP) and Federal Prison Camp (FPC) in Letcher County, Kentucky (the Action). This BO considers the effects of the Action on the Indiana bat (Myotis sodalis) and the northern long-eared bat (Myotis septentrionalis). The Action does not affect designated critical habitat; therefore, this BO does not further address critical habitat.

In the letter, dated May 1, 2017, accompanying the BA, the Bureau made effects determinations for the gray bat (Myotis grisescens) and the Kentucky arrow dater (Etheostoma sagitta spilotum).

The Service concurred with the Bureau’s determination that the Action is not likely to adversely affect the gray bat in a letter dated May 10, 2017, so this species is not further addressed in this BO. In addition, the Bureau determined that the Action would have “no effect” on the Kentucky arrow darter. Federal action agencies do not need concurrence from the Service for “no effect” determinations. Therefore, we have no further comments regarding the Kentucky arrow darter.

A BO evaluates the effects of a Federal action, along with those resulting from interrelated and interdependent actions and non-federal actions unrelated to the proposed Action (cumulative effects), relative to the status of listed species and the status of designated critical habitat. A Service opinion that concludes a proposed Federal action is not likely to jeopardize species and is not likely to destroy or adversely modify critical habitat fulfills the Federal agency’s responsibilities under §7(a)(2) of the ESA of 1973, as amended.

“Jeopardize the continued existence” means to engage in an action that reasonably would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species (50 CFR §402.02).

This BO uses hierarchical numeric section headings. Primary (level-1) sections are labeled sequentially with a single digit (e.g., 1. PROPOSED ACTION). Secondary (level-2) sections within each primary section are labeled with two digits (e.g., 1.1. Action Area), and so on for level-3 sections. The basis of our opinion for the Indiana bat and the basis for our opinion for the northern long-eared bat are contained in separate level-1 sections that address the status, baseline, effects of the Action, cumulative effects, and conclusion relative to each species.

1. PROPOSED ACTION

A BO evaluates the effects of a proposed Action. For purposes of consultation under ESA §7, the effects of a Federal action on listed species or critical habitat include the direct and indirect effects caused by the Action, plus the effects caused by interrelated or interdependent actions.

“Interrelated actions are those that are part of a larger action and depend on the larger action for their justification. Interdependent actions are those that have no independent utility apart from the action under consideration” (50 CFR §402.02).

The Bureau’s proposed Action is to construct and operate a USP and a FPC near Roxana in Letcher County, Kentucky.

Action Area 1.1.

For purposes of consultation under ESA §7, the Action Area is defined as “all areas to be affected directly or indirectly by the Federal action and not merely the immediate area involved in the action” (50 CFR §402.02). The “Action Area” for this consultation encompasses a 4.0 km (2.5 mi) radius from the approximate center of the proposed facilities (Fig. 1). The Action Area is defined in this manner because it represents the area that an Indiana bat maternity colony would be expected to use, if the maternity colony was centered on the site. Centering the assumed maternity colony in this way means that the entire project site is considered, for consultation purposes, known habitat for the Indiana bat and that the colony’s home range and behaviors would be centered in the area where construction and operation of the facility will occur. This helps ensure that our evaluation does not underestimate likely potential effects on the Indiana bat, which could happen if only a portion of the site was considered known habitat.

Similarly, the 4.0 km (2.5 mi) radius would include the area that a northern long-eared bat maternity colony would be expected to use. Northern long-eared bat maternity colonies typically have a smaller home range than this (Fig. 2), so assuming that this larger area is known habitat would also help ensure that our evaluation does not underestimate impacts to the species.

Figure 1. The Action Area of the project (Bureau 2017b).

Figure 2. Forested habitat in a 2.4-km (1.5-mi) buffer and a 4-km (2.5-mi) buffer from the center of the proposed clearing limits (Bureau 2017b).

Land Acquisition 1.2.

Prior to construction, the Bureau would acquire an approximate 231.1-hectare (570-acre) property near Roxana for the proposed facility (Fig. 1). This BO refers to this area as the “property;” this is the same area referred to as the “project area” in the BA and in figures from the BA included in this BO. Of that property, 157.6 hectares (389.5 acres) would not be disturbed and would remain as a buffer to the facility. Of that buffer, 95.4 hectares (235.8 acres) are currently forested.

Compensatory Mitigation 1.3.

As a conservation measure, the Bureau will contribute to the Imperiled Bat Conservation Fund (IBCF) as compensatory mitigation for the adverse effects on Indiana bats and northern long-eared bats that will result from the permanent loss and modification of forested habitat. The contribution amount would be determined according to the process described in the Service’s 2016 Revised Conservation Strategy for Forest-Dwelling Bats in the Commonwealth of Kentucky (USFWS 2016) or an appropriate succeeding document. The contribution would be based on the acreage (currently proposed as 48.8 hectares (120.6 acres)) and the time of year that the forested habitat is removed. The entire contribution will be made prior to tree removal on the project site, as described in a June 5, 2017 email from the Bureau (Appendix A).

Construction Activities 1.4.

The construction phase would take approximately 4-5 years and would include the following activities:

Clearing of vegetation on approximately 73 hectares (180.5 acres), including trees on the

120.6 acres that is currently forested (Fig. 2).

Excavation, including blasting, filling, and grading, on the 73 hectares (180.5 acres).

Construction of a facility that would include the following: USP, a FPC, a central utility plant, a training center with an outdoor firing range and staff training building, a warehouse, a garage/landscape building, access roads, and parking areas.

The following is a list of specific conservation measures that the Bureau would implement during the construction activities:

Develop an erosion and sediment control plan detailing best management practices (BMPs) to be implemented during construction and submit the plan to the Kentucky Division of Water for approval.

Implement the approved erosion and sediment control plan.

Avoid tree removal during the months of June and July.

Avoid blasting from November 15 through March 31.

Conduct all construction activities occurring from April 15 – October 31 in suitable Indiana bat and/or northern long-eared bat habitat during daylight hours.

Aim construction lighting toward construction and away from forested habitat.

Require contractors to inspect vehicles and equipment to ensure that visible plant and seed material has been removed prior to entering the construction area.

Operational Activities1.5.

After the facility is constructed, it would continue in operation indefinitely. The USP and FPC would house approximately 1,216 inmates and require approximately 300 full-time staff. Traffic and human activity will occur on the site. The facility would be illuminated with artificial lighting at night. The outdoor firing range would be used for training one day a month and five days a week (Monday – Friday) during a six-week period each year.

The following is a list of specific conservation measures that the Bureau would implement to reduce impacts during operation of the facility:

Install lights exterior lights (high mast, wall packs, and parking lot and sidewalk light poles) with full cutoff light fixtures (which do not emit direct uplight) for operational activities at the facility.

Fence off the feature identified as a potential hibernaculum and install warning signs around the area to prevent direct disturbance.

Interrelated and Interdependent Actions 1.6.

In its request for consultation, the Bureau did not describe, and the Service is not aware of, any interrelated or interdependent actions in addition to actions that were included in the proposed Action. Therefore, this BO does not further address the topic of interrelated or interdependent actions.

2. INDIANA BAT

This section summarizes the best available data about the biology and current condition of the Indiana bat (Myotis sodalis) throughout its range that are relevant to formulating an opinion about the Action. The Service published its decision to list the Indiana bat as endangered on March 11, 1967 (Federal Register 32[48]:4001) under the Endangered Species Preservation Act of October 15, 1966 (80 Stat. 926; 16 U.S.C. 668aa[c]). The Endangered Species Act (ESA) of 1973 (87 Stat. 884, as amended; 16 U.S.C. 1531 et seq.) subsequently extended full legal protection from unauthorized take to the species. Critical habitat was designated for the species on September 24, 1976 (41 FR 14914). Thirteen hibernacula, including 11 caves and two mines in six states, were listed as critical habitat.

The Service has published a recovery plan that outlines recovery actions (U.S. Fish and Wildlife Service (USFWS) 1983). Briefly, the objectives of the plan are to: (1) protect hibernacula; (2) maintain, protect, and restore summer maternity habitat; and (3) monitor population trends through winter censuses. An agency draft of a revised recovery plan was provided for public review and comment in the Federal Register on April 9, 1999, but has not yet been finalized. A revised draft recovery plan was noticed in the Federal Register for public review and comment on April 16, 2007 (USFWS 2007).

The Service’s Bloomington, Indiana Field Office completed a 5-Year Review of the Indiana bat (USFWS 2009), which summarizes the current status of the species, its progress toward recovery, and the remaining threats to the species. The draft recovery plan and 5-Year Review are available at http://www.fws.gov/midwest/Endangered/mammals/inba/index.html and are hereby incorporated by reference. The 5-Year Review found that all of the required recovery criteria for the Indiana bat had not been achieved, so the species should remain at its current endangered status.

Description of the Indiana Bat 2.1.

The Indiana bat is a temperate, insectivorous, migratory bat that hibernates in caves and mines in the winter and summers in forested areas. It is a medium-sized bat, having a wing span of 9 to 11 inches and weighing only one-quarter of an ounce. It has brown to dark-brown fur and the facial area often has a pinkish appearance. The Indiana bat closely resembles the little brown bat (Myotis lucifugus) and the northern long-eared bat (Myotis septentrionalis). It is distinguished from these species by its foot structure and fur color. The Indiana Bat Draft Recovery Plan (Service 2007) provides a comprehensive summary of the description of the species and is incorporated by reference.

Life Cycle of the Indiana Bat 2.2.

The life cycle of the Indiana bat is summarized in Figure 3. The species hibernates in caves and mines in the winter (typically October through April) and migrates to forested summer habitat.

When arriving at their traditional hibernacula in August-September, Indiana bats “swarm” for several weeks prior to hibernation. Some male bats may begin to arrive at hibernacula as early as July, but females typically arrive later. The time of highest swarming activity in Indiana and Kentucky has been documented as early September (Cope and Humphrey 1977). Swarming is a critical part of the life cycle when Indiana bats converge at hibernacula, mate, and forage until sufficient fat reserves have been deposited to sustain them through the winter (USFWS 1983).

Swarming behavior typically involves large numbers of bats flying in and out of cave entrances throughout the night, while most of the bats continue to roost in trees during the day (Cope and Humphrey 1977). Body weight may increase by 2 grams within a short time, mostly in the form of fat. Copulation occurs on cave ceilings near the cave entrance during the latter part of the swarming period (USFWS 2007). Females may mate their first autumn, whereas males may not mature until the second year (USFWS 2007). By late September, many females have entered hibernation, but males may continue swarming well into October in what is believed to be an attempt to breed with late arriving females.

Figure 3. Indiana bat annual chronology (USFWS 2007).

The initiation of hibernation may vary by latitude and annual weather conditions; however, most bats are hibernating by the end of November (USFWS 2007). Hibernation facilitates survival during winter when insect prey is unavailable. Hibernating Indiana bats cluster on cave ceilings in densities of approximately 300-484 bats per square foot, from approximately October through April. Clusters may protect individuals from temperature changes and reduce sensitivity to disturbance. Like other cave bats, the Indiana bat naturally arouses during hibernation (Sealander & Heidt 1990). Arousals are more frequent and longer at the beginning and end of the hibernation period (Sealander & Heidt 1990). Limited mating occurs throughout the winter and in early April as bats emerge (USFWS 2007).

Spring emergence occurs when outside temperatures have increased and insects (forage) are more abundant (Richter et al. 1993). Most Indiana bats emerge in late March or early April; the timing of annual emergence may vary across the range depending on latitude and annual weather conditions. Females emerge before males. Shortly after emerging from hibernation, the females become pregnant via delayed fertilization from the sperm that has been stored in their reproductive tracts through the winter (USFWS 2007). During the “staging” period, the bats forage for a few days or weeks near their hibernaculum before migrating to their traditional summer roosting areas. Most populations leave their hibernacula by late April. Migration is stressful for the Indiana bat, particularly in the spring when their fat reserves and food supplies are low. As a result, adult mortality may be the highest in late March and April.

Most of the published literature indicates that Indiana bats migrate north for the summer maternity season (USFWS 2007, Gardner and Cook 2002); however, recent migration studies have documented lateral and southward migrations (Piper Roby, pers. comm. 2014). Some reproductive females have been documented to migrate up to 357 miles (Winhold and Kurta 2006) to form maternity colonies; others have been found to form maternity colonies within only a few miles of their hibernacula (U.S. Army Garrison Fort Drum 2011). Males and non-reproductive females have been observed roosting individually and in colonies (Hall 1962, Carter et al. 2001, Whitaker and Brack 2002). Males are commonly found roosting near the hibernacula and have also been documented to migrate long distances to their summer habitat (Kurta and Rice 2002).

Female Indiana bats, like most temperate members of the family Vespertilionidae, give birth to one young each year (Mumford and Calvert 1960, Humphrey et al. 1977, Thomson 1982). The proportion of female Indiana bats that produce young is not well documented. At a colony in Indiana, 23 of 25 female Indiana bats produced volant young during one year and 23 of 28 females the following year (Humphrey et al. 1977). Based on cumulative mist-netting captures over multiple years, Kurta and Rice (2002) estimated that 89% of adult females in Michigan maternity colonies were in reproductive condition (pregnant, lactating, or post-lactating). Racey (1982) notes that a particular ratio of fat to lean mass is normally necessary for puberty and the maintenance of female reproductive activity in mammals. He suggests further that the variation in the age of puberty in bats is due to nutritional factors, possibly resulting from the late birth of young and their failure to achieve threshold body weight in their first autumn. Once puberty is achieved, reproductive rates frequently reach 100% among healthy bats of the family Vespertilionidae and young, healthy female bats can mate in their first autumn as long as their prey base is sufficient to allow them to reach a particular fat to lean mass ratio.

Studies by Belwood (2002) show asynchronous births among members of a colony. This results in great variation in size of juveniles (newborn to almost adult size young) in the same colony.

Young Indiana bats are capable of flight within a month of birth. Young born in early June may be flying as early as the first week of July (Clark et al. 1987), with others flying from mid- to late July. Mortality between birth and weaning was found to be about 8% (Humphrey et al. 1977).

The average life span of the Indiana bat is 5 to 10 years, but banded individuals have been documented living as long as 14 and 15 years (Humphrey and Cope 1977). Using winter sampling of unknown-age bats over a 23-year period, Humphrey and Cope (1977) estimated annual survival. Female survivorship in an Indiana population was 76% for ages 1 to 6 years and 66% for ages 6 to 10 years. Male survivorship was 70% for ages 1 to 6 years and 36% for ages 6 to 10 years. Following 10 years, the survival rate for females dropped to only 4% (Humphrey and Cope 1977).

Habitat Characteristics and Use of the Indiana Bat 2.3.

2.3.1. Winter Habitat

Indiana bats roost in caves or mines with configurations that provide a suitable temperature and humidity microclimate (Brack et al. 2003, USFWS 2007). Only a small percentage of caves have areas that meet these requirements (Brack et al. 2003, USFWS 2007). Mid-winter temperatures range from 4-8 C (39 to 46º F) (USFWS 1983). Stable, low temperatures allow bats to maintain low metabolic rates and conserve fat reserves to survive the winter (USFWS 2007). In many caves, these areas are located near the cave entrance, but they may also be deeper in the cave where cold air flows and is trapped. Relative humidity of roosts usually ranges from 74% to just below saturation, although readings as low as 54% have been recorded.

Hibernacula often contain large populations of several species of bats. Other bat species found in Indiana bat hibernacula include little brown bats (Myotis lucifugus), tri-colored bats (Perimyotis subflavus), northern long-eared bats (Myotis septentrionalis), gray bats (Myotis grisescens), big brown bats (Eptesicus fuscus), and silver-haired bats (Lasionycteris noctivagans) (Brack et al. 2003).

2.3.2. Summer Habitat

Summering Indiana bats (males and females) use forested habitat for roosting, foraging, and commuting. Indiana bats are often associated with floodplain or riparian forests with large trees, scattered canopy gaps, and open understories (USFWS 2007). Research has showed adaptability in habitats used, including upland forests, forests altered by grazing, swine feedlots, row-crops, hay fields, residences, clear-cut harvests, and shelterwood cuts (Garner and Gardner 1992, USFWS 1999).

Suitability of a roost tree is determined by its condition (dead or alive), suitability of loose bark, solar exposure, spatial relationship to other trees, and tree’s spatial relationship to water sources and foraging areas. Potentially suitable roost trees can be trees of any species with bark separating from the tree after the tree dies, senesces, or is injured and living species of hickories (Carya spp.) and large white oaks (Quercus alba) with shaggy bark. Many maternity colonies have been associated with oak-hickory and elm-ash-cottonwood forest types. Tree cavities, hollow portions of tree boles or limbs, and crevice and splits from broken tops occasionally have been used as roosts, usually by individual bats. Roost longevity is variable due to many factors, such as the rate at which bark sloughs off or the tree falls down. Some roosts may only be habitable for 1-2 years, but species with good bark retention, such as slippery elm (Ulmus rubra), cottonwood (Populus deltoides), green ash (Fraxinus pennsylvanica), and various oaks (Quercus spp.) and hickories (Carya spp.) may provide habitat for 4-8 years (USFWS 1999).

Trees in excess of 40 cm (15.7 in) diameter-at-breast-height (dbh) are considered optimal for maternity colonies, but trees in excess of 22 cm (8.6 in) dbh are used as alternate roosts (USFWS 2002). Females have been documented using roost trees as small as 14 cm (5.5 in) dbh (Kurta 2005). The average size of roost trees used by males tends to be smaller than the roost trees used by female maternity colonies; in one instance, a male was observed in a roost tree 6.4 cm (2.5 in) dbh (Gumbert et al. 2002).

Garner and Gardner (1992) found that Indiana bats select for roosts far from paved roads.

Conversely, several roosts at the Indianapolis Airport have been located near I-70 and near lightly traveled, low maintenance roads (USFWS 2002). Although Indiana bats may be more adaptable than previously thought, it still is not known how a maternity colony’s stability and reproductive success responds to increasing levels of habitat alteration and fragmentation.

Maternity colonies use a range of 8 to 25 trees per season (Callahan et al. 1997, Kurta et al.

2002). The extent and configuration of the roosting area is probably determined by availability of suitable roost trees. Distances between roosts can be a few meters to a few kilometers (Kurta et al. 1996, 2002). Primary roosts are generally larger in diameter and located in openings or at the edge of forest stands, while alternate roosts can either be in openings or the interior of the forest stand. Maternity colony movements among multiple roosts seem to depend on climatic changes, particularly solar radiation (Humphrey et al. 1977). Cool temperatures can delay fetal development and growth of juvenile young; selection of maternity roost sites may be critical to reproductive success. Kurta et al. (1993) suggest movement between roosts may be the way that bats deal with the ephemeral nature of roost trees. It is not known how many alternate roosts must be available to assure retention of a colony within a particular area, but large, nearby forest tracts would improve the potential for an area to provide adequate roosting habitat (Callahan 1993, Callahan et al. 1997).

Indiana bats feed on aquatic and terrestrial insects. Diet varies seasonally and among different ages, sexes, and reproductive status (USFWS 1999). Numerous foraging habitat studies have found that Indiana bats forage in closed to semi-open forested habitats and forest edges located in floodplains, riparian areas, lowlands, and uplands; old fields and agricultural fields are also used (USFWS 2007). At a study site near the Indianapolis International Airport, Sparks et al.

(2005) found Indiana bats spending nearly 51% of their time foraging over agricultural fields with movements focused on a riparian corridor. Indiana bats frequently forage along riparian corridors and obtain water from streams; ponds and water-filled road ruts in the forest uplands are also serve as water sources.

Very little research has focused on the use of travel corridors by Indiana bats. Most information pertaining to bat movements and travel corridors is incidental to other portions of a study and/or general observations. Murray and Kurta (2004) showed that Indiana bats increased commuting distance by 55% to follow tree-lined paths rather than flying over large agricultural fields, some of which were at least 1 km (0.6 mi) wide. Data collected from a residential development in northern New York showed use of linear features (i.e., hedgerows and tree-lined fence rows) by Indiana bats (Environmental Solutions and Innovations, Inc. 2006). Apparently suitable, but distant, forest patches may not be available to Indiana bats unless they are connected by a wooded corridor; however, the maximum size of an opening Indiana bats may cross is not known.

Home range size may vary between seasons, sexes, and reproductive status of the females (Lacki et al. 2007). Menzel et al. (2005) tracked seven female and four male Indiana bats from May to August in Illinois. No significant differences in home ranges between males and females were observed, and home range estimates were subsequently grouped to obtain a mean summer home range of 144.4 hectares (357 acres). Watrous et al. (2006) calculated a mean home range of 83 hectares (205 acres) for 14 female Indiana bats in Vermont. Without site-specific data, the Service generally considers the potential home range for an Indiana bat to include all suitable habitat within 4 km (2.5 mi) of documented roost(s) (USFWS 2011), recognizing the area of actual use may be just a portion of that area.

Gumbert et al. (2002) differentiated between roost tree and roost area fidelity in Indiana bats and found that bats are faithful to both areas and particular trees within those areas. Indiana bats also show a high degree of fidelity to foraging ranges. Kurta and Murray (2002) documented recapturing 41% of females when mist netting within the same area in subsequent years. Indiana bat maternity colonies in Illinois, Indiana, Michigan, and Kentucky have been shown to use the same roosting and foraging areas during subsequent years (Gardner et al. 1991a; Humphrey et al.

1977; Kurta and Murray 2002; Kurta et al. 1996, 2002). Bats using familiar foraging and roosting areas are thought to benefit from decreased susceptibility to predators, increased foraging efficiency, and the ability to switch roosts in case of emergencies or alterations surrounding the original roost (Gumbert et al. 2002).

2.3.3. Spring and Fall Habitat

In general, Indiana bats use habitats in the spring and fall similar to those selected during the summer. Suitable spring staging/fall swarming habitat consists of the variety of forested/wooded habitats where they roost, forage, and travel. These areas are most typically within 10 miles of a P1/P2 hibernaculum and 5 miles of a P3/P4 hibernacula1; however, use of habitat areas that are farther than 10 miles from a P1/P2 hibernaculum or farther than 5 miles from a P3/P4 hibernaculum have been documented (Kiser and Elliot 1996; MacGregor et al.

1999; Rommé et al. 2002; Hawkins et al. 2005.

Status and Distribution of the Indiana Bat2.4.

Indiana bats are found over most of the eastern half of the United States (Fig. 4). The recovery program for the Indiana bat delineates four Recovery Units (RUs): the Ozark-Central, Midwest, Appalachian Mountains, and Northeast RUs (USFWS 2007).

Because the vast majority of Indiana bats form dense aggregations or “clusters” on the ceilings of a relatively small number of hibernacula (i.e., caves and mines) each winter, conducting standardized surveys of the hibernating bats during that time is the most feasible and efficient means of estimating and tracking population and distribution trends across the species’ range.

Collectively, winter hibernacula surveys provide the Service with the best representation of the overall population status and relative distribution that is available.

The data regarding Indiana bat abundance prior to federal listing are limited, but the information suggests that Indiana bats were once far more abundant than they were in the 1960s. Tuttle and colleagues, for example, believe the overall abundance of Indiana bats likely rivaled that of the now extinct passenger pigeon (USFWS 2007). The basis for the estimates of millions of Indiana bats prior to European settlement is primarily based on historic accounts (e.g., Blatchley 1897, Silliman et al. 1851), extensive staining left on the ceilings of several historic hibernacula (Tuttle 1997, 1999), and other paleontological evidence (Munson and Keith 1984, Toomey et al. 2002).

For example, an analysis of bone deposits in Bat Cave, Kentucky revealed that an estimated 300,000 Indiana bats died during a single flood event at some point in history (Hall 1962).

1 Priority 1 (P1) hibernacula have a current or historical winter population of ≥ 10,000 Indiana bats; priority 2 (P2) have 1,000 -9.999 bats; priority 3 (P3) have 50-999 bats; and priority 4 (P4) have < 50 bats (USFWS 2007).

Figure 4. Distribution of counties with known summer and winter records of the Indiana bat.

When the Indiana bat was originally listed as endangered in 1967, there were approximately 883,300 bats, and most of these hibernated in a small number of hibernacula (Clawson 2002).

Since the species was listed, its population numbers have apparently continued to decline through approximately 2001. Although some winter bat surveys began as early as the late 1950s, systematic surveys were not conducted across the range until the mid-1980s when there were an estimated 678,750 Indiana bats (Clawson 2002). Since being listed, large population declines have been observed, especially at hibernacula in Kentucky and Missouri. Caves in Kentucky suffered dramatic losses due to changes in microclimate caused by poor cave gate design at two of the three most important hibernacula (Humphrey 1978), and Indiana bat numbers in Kentucky hibernacula had continued to decline until 2005 when an increase was first observed (USFWS, unpublished data, 2007). Despite recovery efforts, Indiana bats in Missouri caves have continuously declined with a loss of more than 80% of the previous population size (Clawson 2002). The rangewide population estimate dropped approximately 57% from 1965 to 2001

(USFWS 2007).

The Service has collated the population data gathered during the 2007 through 2015 biennial winter hibernacula surveys from throughout the Indiana bat’s range and determined that the Indiana bat’s 2015 range-wide population stands at approximately 523,636 bats, which is a 9.8% decrease over the 2013 range-wide population estimate of 580,717 bats (Fig. 5). The range-wide, biennial population estimates had been increasing from 2001 to 2007, indicating that the species’ long-term decline had been arrested and likely reversed (USFWS 2015). The observed range-wide decline since 2007 is likely attributable to White-Nose Syndrome (or “WNS”; see discussion below), especially for decreased population estimates in the Northeast Recovery Unit.

Winter surveys in 2014-2015 found hibernating Indiana bats dispersed across 16 states. Over 90% of the estimated range-wide population hibernated in four states – Indiana (35.5%), Missouri (35.5%), Kentucky (12.6%), and Illinois (10.7%) (USFWS 2015).

Summer distribution of the Indiana bat occurs throughout a wider geographic area than its winter distribution. Most summer occurrences are from the upper Midwest including southern Iowa, northern Missouri, much of Illinois and Indiana, southern Michigan, Wisconsin, western Ohio, and Kentucky. In the past decade, many summer maternity colonies have been found in the northeastern states of Pennsylvania, Vermont, New Jersey, New York, West Virginia, and Maryland. Maternity colonies have also been found in the south, including northern Arkansas, Georgia, Alabama, Mississippi (Piper Roby, pers. comm. 2014), and southwestern North Carolina (Britzke et al. 2003, Service 2007). Non-reproductive summer records for the Indiana bat have also been documented in eastern Oklahoma, northern Mississippi, Alabama, and Georgia.

Figure 5. Indiana bat rangewide population estimates from 1981-2015.

Stressors to the Indiana Bat2.5.

2.5.1. Destruction/Degradation of Hibernacula

There are well-documented examples of modifications to Indiana bat hibernacula that affected the thermal regime of the cave and, thus, the ability of the cave to support hibernating Indiana bats, as summarized in the draft revised Recovery Plan (USFWS 2007). Generally, threats to the integrity of hibernacula have decreased since the time that Indiana bats were listed as endangered under the ESA. Increasing awareness of the importance of cave microclimates to hibernating bats and regulatory authorities under the ESA have reduced, but not eliminated, this threat. In addition to purposeful modifications, there are threats from stochastic events (e.g., collapse in mines, flooding).

2.5.2. Loss/Degradation of Forested Habitat

Loss of forest cover and degradation of forested habitats have been cited as contributing to the decline of Indiana bats (USFWS 1983, Garner and Gardner 1992, Drobney and Clawson 1995, Whitaker and Brack 2002). Throughout the range of the Indiana bat, there is less forest land now than there was prior to European settlement (Smith et al. 2003), particularly within the core of the species’ range in the Midwest. Conversion to agriculture has been the largest single cause of forest loss. The conversion of floodplain and bottomland forests, recognized as high quality habitats for Indiana bats, has been a particular cause of concern (Humphrey 1978).

More recently, since the 1950s, some marginal farmlands have been abandoned and allowed to revert to forest and there has been a net increase in forest land within the range of the Indiana bat, particularly in the Northeast (Smith et al. 2003). Forest cover has also increased within the Midwest Recovery Unit (Smith et al. 2003). Not only has the amount of forest cover increased since the 1950s, but also the average diameter of trees has increased (Smith et al. 2003), which may equate to an increased supply of suitable roost trees for Indiana bats.

Urbanization and development is currently the greatest contributor to forested habitat loss within the range of the Indiana bat (Wear and Greis 2002; U.S. Forest Service (USFS) 2005, 2006), which results in permanent conversion to land uses generally unsuitable for Indiana bats. At a study site in central Indiana, Indiana bats avoided foraging in a high-density residential area (Sparks et al. 2005), although maternity roosts have been found in low-density residential areas (Belwood 2002). Duchamp (2006) found that greater amounts of urban land use was negatively related to bat species diversity in north-central Indiana; several bat species, including the Indiana bat, were less likely to occur in landscapes with greater amounts of urban and suburban development. Development directly destroys habitat and fragments remaining habitat.

Forest cover is not a completely reliable predictor of where Indiana bat maternity colonies will be found on…