Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Eastern Small-Footed Bat and the Northern Long-Eared Bat as Endangered or Threatened Species; Listing the Northern Long-Eared Bat as an Endangered Species

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DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 17 [Docket No. FWS-R5-ES-2011-0024; 4500030113] RIN 1018-AY98 Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Eastern Small-Footed Bat and the Northern Long-Eared Bat as Endangered or Threatened Species; Listing the Northern Long-Eared Bat as an Endangered Species AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule; 12-month finding.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), announce a 12-month finding on a petition to list the eastern small-footed bat ( Myotis leibii ) and the northern long-eared bat ( Myotis septentrionalis ) as endangered or threatened under the Endangered Species Act of 1973, as amended (Act) and to designate critical habitat. After review of the best available scientific and commercial information, we find that listing the eastern small-footed bat is not warranted but listing the northern long-eared bat is warranted. Accordingly, we propose to list the northern long-eared bat as an endangered species throughout its range under the Act. We also determine that critical habitat for the northern long-eared bat is not determinable at this time. This proposed rule, if finalized, would extend the Act's protections to the northern long-eared bat. The Service seeks data and comments from the public on this proposed listing rule for the northern long-eared bat.

DATES:

We will consider comments received or postmarked on or before December 2, 2013. Comments submitted electronically using the Federal eRulemaking Portal (see ADDRESSES section, below) must be received by 11:59 p.m. Eastern Time on the closing date. We must receive requests for a public hearing, in writing, at the address shown in the FOR FURTHER INFORMATION CONTACT section by November 18, 2013.

ADDRESSES:

You may submit comments by one of the following methods:

2, 2013. Comments submitted electronically using the Federal eRulemaking Portal (see ADDRESSES section, below) must be received by 11:59 p.m. Eastern Time on the closing date. We must receive requests for a public hearing, in writing, at the address shown in the FOR FURTHER INFORMATION CONTACT section by November 18, 2013.

ADDRESSES:

You may submit comments by one of the following methods:

(1) In the Search box, enter Docket No. FWS-R5-ES-2011-0024, which is the docket number for this rulemaking. Then, in the Search panel on the left side of the screen, under the Document Type heading, click on the Proposed Rules link to locate this document. You may submit a comment by clicking on “Comment Now!” If your comments will fit in the provided comment box, please use this feature of http://www.regulations.gov, as it is most compatible with our comment review procedures. If you attach your comments as a separate document, our preferred file format is Microsoft Word. If you attach multiple comments (such as form letters), our preferred format is a spreadsheet in Microsoft Excel.

(2) By hard copy: Submit by U.S. mail or hand-delivery to: Public Comments Processing, Attn: FWS-R5-ES-2011-0024; Division of Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.

We request that you send comments only by the methods described above. We will post all information received on http://www.regulations.gov . This generally means that we will post any personal information you provide us (see the Information Requested section below for more details).

FOR FURTHER INFORMATION CONTACT:

Peter Fasbender, Field Supervisor, U.S. Fish and Wildlife Service, Green Bay Ecological Services Office, 2661 Scott Tower Dr., New Franken, Wisconsin, 54229; by telephone (920) 866-3650 or by facsimile (920) 866-1710. mailto: If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339

ils).

FOR FURTHER INFORMATION CONTACT:

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule. Under the Act, if a species is determined to be an endangered or threatened species throughout all or a significant portion of its range, we are required to promptly publish a proposal in the Federal Register and make a determination on our proposal within one year. Listing a species as an endangered or threatened species can only be completed by issuing a rule.

This document consists of:

• Our status review and finding that listing is warranted for the northern long-eared bat and not warranted for the eastern small-footed bat.

• A proposed rule to list the northern long-eared bat as an endangered species. This rule assesses best available information regarding the status of and threats to the northern long-eared bat.

The basis for our action. Under the Act, we can determine that a species is an endangered or threatened species based on any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. We have determined that the northern long-eared bat is in danger of extinction, predominantly due to the threat of white-nose syndrome (Factor C). However, other threats (Factors A, B, E) when combined with white-nose syndrome heighten the level of risk to the species.

We will seek peer review

sting regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. We have determined that the northern long-eared bat is in danger of extinction, predominantly due to the threat of white-nose syndrome (Factor C). However, other threats (Factors A, B, E) when combined with white-nose syndrome heighten the level of risk to the species.

We will seek peer review. We are seeking comments from knowledgeable individuals with scientific expertise to review our analysis of the best available science and application of that science and to provide any additional scientific information to improve this proposed rule. Because we will consider all comments and information we receive during the comment period, our final determination may differ from this proposal.

Information Requested

We intend that any final action resulting from this proposed rule will be based on the best scientific and commercial data available and be as accurate and as effective as possible. Therefore, we request comments or information from other concerned Federal and State agencies, the scientific community, or any other interested party concerning this proposed rule. We particularly seek comments regarding the northern long-eared bat concerning:

(1) The species' biology, range, and population trends, including:

(a) Habitat requirements for feeding, breeding, and sheltering;

(b) Genetics and taxonomy;

(d) Historical and current population levels, and current and projected trends; and

We particularly seek comments regarding the northern long-eared bat concerning:

(1) The species' biology, range, and population trends, including:

(a) Habitat requirements for feeding, breeding, and sheltering;

(b) Genetics and taxonomy;

(d) Historical and current population levels, and current and projected trends; and

(e) Past and ongoing conservation measures for the species, its habitat, or both.

(2) Any information on the biological or ecological requirements of the species, and ongoing conservation measures for the species and its habitat.

(3) Biological, commercial trade, or other relevant data concerning any threats (or lack thereof) to this species and regulations that may be addressing those threats.

(4) Current or planned activities in the areas occupied by the species and possible impacts of these activities on this species.

(5) Additional information regarding the threats to the species under the five listing factors, which are:

(a) The present or threatened destruction, modification, or curtailment of its habitat or range;

(b) Overutilization for commercial, recreational, scientific, or educational purposes;

(d) The inadequacy of existing regulatory mechanisms; and

(e) Other natural or manmade factors affecting its continued existence.

(6) The reasons why areas should or should not be designated as critical habitat as provided by section 4 of the Act (16 U.S.C. 1531 et seq. ), including the possible risks or benefits of designating critical habitat, including risks associated with publication of maps designating any area on which this species may be located, now or in the future, as critical habitat.

(7) The following specific information on:

(a) The amount and distribution of habitat for northern long-eared bat;

d by section 4 of the Act (16 U.S.C. 1531 et seq. ), including the possible risks or benefits of designating critical habitat, including risks associated with publication of maps designating any area on which this species may be located, now or in the future, as critical habitat.

(7) The following specific information on:

(a) The amount and distribution of habitat for northern long-eared bat;

(b) What areas, that are currently occupied and that contain the physical and biological features essential to the conservation of this species, should be included in a critical habitat designation and why;

(c) Special management considerations or protection that may be needed for the essential features in potential critical habitat areas, including managing for the potential effects of climate change;

(d) What areas not occupied at the time of listing are essential for the conservation of this species and why;

(e) The amount of forest removal occurring within known summer habitat for this species;

(f) Information on summer roost habitat requirements that are essential for the conservation of the species and why; and

(g) Information on species winter habitat (hibernacula) features and requirements for the species.

(8) Information on the projected and reasonably likely impacts of changing environmental conditions resulting from climate change on the species and its habitat.

Please note that submissions merely stating support for or opposition to the action under consideration without providing supporting information, although noted, will not be considered in making a determination, as section 4(b)(1)(A) of the Act directs that determinations as to whether any species is an endangered or threatened species must be made “solely on the basis of the best scientific and commercial data available.”

of the Act directs that determinations as to whether any species is an endangered or threatened species must be made “solely on the basis of the best scientific and commercial data available.”

You may submit your comments and materials concerning this proposed rule by one of the methods listed in ADDRESSES . We request that you send comments only by the methods described in the ADDRESSES section. If you submit information via http://www.regulations.gov, your entire submission—including any personal identifying information—will be posted on the Web site. If your submission is made via a hardcopy that includes personal identifying information, you may request at the top of your document that we withhold this information from public review. However, we cannot guarantee that we will be able to do so. We will post all hardcopy submissions on http://www.regulations.gov . Please include sufficient information with your comments to allow us to verify any scientific or commercial information you include.

Comments and materials we receive, as well as supporting documentation we used in preparing this proposed rule, will be available for public inspection on http://www.regulations.gov, or by appointment, during normal business hours, at the U.S. Fish and Wildlife Service, Green Bay, Wisconsin Field Office (see FOR FURTHER INFORMATION CONTACT ).

Background

Section 4(b)(3)(B) of the Act requires that, for any petition to revise the Federal Lists of Threatened and Endangered Wildlife and Plants that contains substantial scientific or commercial information that listing a species may be warranted, we make a finding within 12 months of the date of receipt of the petition on whether the petitioned action is: (a) Not warranted; (b) warranted; or (3) warranted, but the immediate proposal of a regulation implementing the petitioned action is precluded by other pending proposals to determine whether any species is endangered or threatened, and expeditious progress is being made to add or remove qualified species from the Fede

nths of the date of receipt of the petition on whether the petitioned action is: (a) Not warranted; (b) warranted; or (3) warranted, but the immediate proposal of a regulation implementing the petitioned action is precluded by other pending proposals to determine whether any species is endangered or threatened, and expeditious progress is being made to add or remove qualified species from the Federal Lists of Endangered and Threatened Wildlife and Plants. In this document, we have determined that the petitioned action to list the eastern small-footed bat is not warranted, but listing the northern long-eared bat is warranted and; therefore, we are publishing a proposed rule to list the northern long-eared bat.

Previous Federal Actions

On September 18, 1985 (50 FR 37958), November 21, 1991 (56 FR 58804), and November 15, 1994 (59 FR 58982), the Service issued notices of review identifying the eastern small-footed bat as a “category-2 candidate” for listing under the Act. However, on December 5, 1996 (50 FR 64481), the Service discontinued the practice of maintaining a list of species regarded as “category-2 candidates,” that is, taxa for which the Service had insufficient information to support issuance of a proposed listing rule.

On January 21, 2010, we received a petition from the Center for Biological Diversity, requesting that the eastern small-footed bat and northern long-eared bat be listed as endangered or threatened and that critical habitat be designated under the Act. The petition clearly identified itself as such and included the requisite identification information for the petitioner, as required by 50 CFR 424.14(a). In a February 19, 2010, letter to the petitioner, we acknowledged receipt of the petition and stated that we would review the petitioned request for listing and inform the petitioner of our determination upon completion of our review. On June 23, 2010, we received a notice of intent to sue (NOI) from the petitioner for failing to make a timely 90-day finding

ioner, as required by 50 CFR 424.14(a). In a February 19, 2010, letter to the petitioner, we acknowledged receipt of the petition and stated that we would review the petitioned request for listing and inform the petitioner of our determination upon completion of our review. On June 23, 2010, we received a notice of intent to sue (NOI) from the petitioner for failing to make a timely 90-day finding. In a letter dated July 20, 2010, we responded to the NOI, stating that we had assigned lead for the two bat species to the Services' Midwest and Northeast Regions, and that although completing the 90-day finding within the 90 days following our receipt of the petition was not practicable, the Regions were recently allocated funding to work on the findings and had begun review of the petition. On June 29, 2011, we published in the Federal Register (76 FR 38095) our finding that the petition to list the eastern small-footed bat and northern long-eared bat presented substantial information indicating that the requested action may be warranted, and we initiated a status review of the species. On July 12, 2011, the Service filed a proposed settlement agreement with the Center for Biological Diversity in a consolidated case in the U.S. District Court for the District of Columbia. The settlement agreement was approved by the court on September 9, 2011. As part of this settlement agreement, the Service agreed to complete a status review for the eastern small-footed bat and northern long-eared bat by September 30, 2013, and if warranted for listing, publish a proposed listing rule also by that date.

Species Information

Eastern Small-Footed Bat

Taxonomy and Species Description

mation

Eastern Small-Footed Bat

Taxonomy and Species Description

The eastern small-footed bat ( Myotis leibii ) belongs to the Order Chiroptera, Vespertilio leibii (Audubon and Bachman 1842, p. 284) and Myotis subulatus (Miller and Allen 1928, p. 164). This species also has been identified by different common names: Leib's bat (Audubon and Bachman 1842, p. 284), least brown bat (Mohr 1936, p. 62), and Leib's masked bat or least bat (Hitchcock 1949, p. 47). The Service agrees with the treatment in Best and Jennings (1997, p. 1) regarding the scientific and common names and will refer to this species as eastern small-footed bat and recognizes it as a listable entity under the Act.

The eastern small-footed bat is one of the smallest North American bats, weighing from 3 to 8 grams (g) (0.1 to 0.3 ounces (oz)) (Merritt 1987, p. 94). Total body length is from 73 to 85 millimeters (mm) (2.9 to 3.4 inches (in)), tail length is from 31 to 34 mm (1.2 to 1.3 in), forearm length is from 30 to 36 mm (1.2 to 1.4 in), and wingspan is from 212 to 248 mm (8.4 to 9.8 in) (Barbour and Davis 1969, p. 103; Merritt 1987, p. 94; Erdle and Hobson 2001, p. 6; Amelon and Burhans 2006, p. 57). Eastern small-footed bats are recognized by their short hind feet (less than 8 mm (0.3 in)), short ears (less than 15 mm (0.6 in)), black facial mask, black ears, keeled calcar (a spur of cartilage that helps spread the wing membrane), and small flattened skull (Barbour and Davis 1969, p. 103; Best and Jennings 1997, p. 1). The wings and interfemoral membrane (the wing membrane between the tail and hind legs) are black. The dorsal fur is black at the roots and tipped with light brown, giving it a dark yellowish-brown appearance. The ventral fur is gray at the roots and tipped with yellowish-white (Audubon and Bachman 1842, pp. 284-285).

Distribution and Abundance

The eastern small-footed bat occurs from eastern Canada and New England south to Alabama and Georgia and west to Oklahoma

and hind legs) are black. The dorsal fur is black at the roots and tipped with light brown, giving it a dark yellowish-brown appearance. The ventral fur is gray at the roots and tipped with yellowish-white (Audubon and Bachman 1842, pp. 284-285).

Distribution and Abundance

The eastern small-footed bat occurs from eastern Canada and New England south to Alabama and Georgia and west to Oklahoma. The species' range includes 26 states and 2 Canadian provinces, including Alabama, Arkansas, Connecticut, Delaware, Georgia, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Mississippi, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virginia, West Virginia, Ontario, and Quebec. Relative to other species of bats in its range, eastern small-footed bats are considered uncommon (Best and Jennings 1997, p. 3). They historically have been considered rare because of their patchy distribution and generally low population numbers (Mohr 1932, p. 160). In areas with abundant summer habitat, however, they have been found to be relatively common (Brack et al., unpublished manuscript). Johnson et al. (2011, p. 99) observed that capture success decreased as the distance increased from suitable roosting habitat. Eastern small-footed bats have also been noted for their ability to detect and avoid mist nets, which are typically relied upon for summer bat surveys (Barbour and Davis 1974, p. 84), suggesting their numbers could be underrepresented (Tyburec 2012).

nted (Tyburec 2012).

Eastern small-footed bats have most often been detected during winter hibernacula (the areas where the bats hibernate during winter; primarily caves and mines) surveys (Barbour and Davis 1969, p. 103). Two-hundred eighty-nine hibernacula (includes cave and abandoned mine features only) have been identified across the species' range, though most contain just a few individuals. The majority of known hibernacula occur in Pennsylvania (n=55), New York (n=53), West Virginia (n=50), Virginia (n=33), Kentucky (n=26), and North Carolina (n=25), but hibernacula are also known from Tennessee (approximately 12), Arkansas (n=9), Maryland (n=7), Vermont (n=6), Missouri (n=3), Maine (n=2), Massachusetts (n=2), New Hampshire (n=2), New Jersey (n=2), Indiana (n=1), and Oklahoma (n=1). In Vermont, eastern small-footed bats were consistently found in very small numbers and often not detected at all during periodic surveys of hibernacula (Trombulak et al. 2001, pp. 53-57). Their propensity for hibernating in cracks and crevices in cave and mine floors and ceilings may also mean they are more often overlooked than other cave-hibernating bat species. The largest number of hibernating individuals ever reported for the species was 2,383, which were found in a mine in Essex County, New York (Herzog 2013, pers. comm.).

In Pennsylvania, eastern small-footed bats were observed at 55 of 480 (12 percent) hibernacula from 1984 to 2011, accounting for only 0.1 percent of the total bats observed during winter hibernacula surveys. The number of eastern small-footed bats observed per site fluctuates annually and ranges from 1 to 46 (mean = 4, median = 1). Summer mist-net surveys also confirm that eastern small-footed bats are observed less frequently than other bat species. From 1995 to 2011, of the 7,007 bat mist-net surveys conducted in Pennsylvania, only 104 surveys (2 percent) include eastern small-footed bat captures, representing only 0.3 percent of the total bats captured (Butchkoski 2011, unpublished data)

om 1 to 46 (mean = 4, median = 1). Summer mist-net surveys also confirm that eastern small-footed bats are observed less frequently than other bat species. From 1995 to 2011, of the 7,007 bat mist-net surveys conducted in Pennsylvania, only 104 surveys (2 percent) include eastern small-footed bat captures, representing only 0.3 percent of the total bats captured (Butchkoski 2011, unpublished data). Of the other states within the species' range, seven states (Alabama, Connecticut, Delaware, Indiana, Massachusetts, Mississippi, and Rhode Island) have no summer records, and of those States with summer records, the most have fewer than 20 capture locations (Service, unpublished data).

Illustrating the potential for under-representation of the species during hibernacula surveys, the following is an example from one state. From 1939 to 1944, over 100 caves were surveyed in Pennsylvania (and a portion of West Virginia), and out of these, eastern small-footed bats were observed at only 7 sites, totaling 363 individuals. In 1978 and 1979, the same seven caves were surveyed again, and no eastern small-footed bats were observed (Felbaum et al. 1995, p. 24). However, surveys conducted from 1980 to 1988, found eastern small-footed bats inhabiting 21 hibernacula from an 8-county area in Pennsylvania (Dunn and Hall 1989, p. 169), and by 2011, surveys had confirmed presence at 55 sites in a 14-county area (Pennsylvania Game Commission, unpublished data). This example is typical of the species' potential for fluctuation throughout its range.

Habitat

Winter Habitat

Eastern small-footed bats have been observed most often overwintering in hibernacula that include caves and abandoned mines ( e.g., limestone, coal, iron). Because they tolerate colder temperatures more so than other Myotis bats, they are most often encountered close to cave or mine entrances where humidity is low and temperature fluctuations may be high relative to more interior areas (Hitchcock 1949, p. 53; Barbour and Davis 1969, p

served most often overwintering in hibernacula that include caves and abandoned mines ( e.g., limestone, coal, iron). Because they tolerate colder temperatures more so than other Myotis bats, they are most often encountered close to cave or mine entrances where humidity is low and temperature fluctuations may be high relative to more interior areas (Hitchcock 1949, p. 53; Barbour and Davis 1969, p. 104; Best and Jennings 1997, pp. 2-3; Veilleux 2007, p. 502). On occasion, however, they have been observed hibernating deep within cave interiors (Hitchcock 1965, p. 9; Gunier and Elder 1973, p. 490). In Pennsylvania, caves containing wintering populations of eastern small-footed bats have been found in hemlock-dominated forests in the foothills of mountains that rise to 610 meters (m) (2000 feet (ft)) (Mohr 1936, p. 63). Dunn and Hall (1989, p. 169) noted that 52 percent of Pennsylvania hibernacula

Winter habitat used by eastern small-footed bats may also include non-cave or non-mine features, such as rock outcrops and stone highway culverts. In Pennsylvania, eastern small-footed bats were observed hibernating multiple years during the months of January and March in a rock outcrop located high above the Juniata River. The bats were found in small cracks and crevices at the back of a 4.6-m (15-ft) depression in the rock outcrop. Big brown bats ( Eptesicus fuscus ) were also present. Temperatures within the cracks where bats were hibernating ranged from 1.7 to 8.3 °C (35 to 47 °F). Observers noted that it seemed a cold, unstable site for hibernating bats (Pennsylvania Game Commission, unpublished data). In West Virginia, an eastern small-footed bat was observed in a crack in a rock outcrop about 1.5 to 1.8 m (5 to 6 ft) above the ground in February (Stihler 2012, pers. comm.). Sasse et al. (in press) reported a single female eastern small-footed bat hibernating inside a stone highway culvert underneath a highway in Arkansas. Mohr (1936, p

ing bats (Pennsylvania Game Commission, unpublished data). In West Virginia, an eastern small-footed bat was observed in a crack in a rock outcrop about 1.5 to 1.8 m (5 to 6 ft) above the ground in February (Stihler 2012, pers. comm.). Sasse et al. (in press) reported a single female eastern small-footed bat hibernating inside a stone highway culvert underneath a highway in Arkansas. Mohr (1936, p. 64) noted fluctuations in the number of eastern small-footed bats observed at hibernacula during winter surveys conducted 2 to 3 weeks apart, suggesting bats left caves and mines during warmer winter periods only to return when it became colder. Consequently, eastern small-footed bats may be utilizing non-cave or non-mine rock features during mild or milder portions of winters, but to what extent they may be doing so is largely unknown.

Summer Habitat

In the summer, eastern small-footed bats are dependent on emergent rock habitats for roosting and on the immediately surrounding forests for foraging (Johnson et al. 2009, p. 5). Eastern small-footed bats have been observed roosting singly or in small maternity colonies in talus fields and slopes, rock-outcrops, rocky ridges, sandstone boulders, shale rock piles, limestone spoil piles, rocky terrain of strip mine areas, and cliff crevices, but have also been found on humanmade structures such as buildings and expansion joints of bridges (Barbour and Davis 1969, p. 103; McDaniel et al. 1982, p. 93; Merritt 1987, p. 95; MacGregor and Kiser 1998, p. 175; Roble 2004, p. 43; Amelon and Burhans 2006, p. 58; Chenger 2008a, p. 10; Chenger 2008b, p. 6; Johnson et al. 2011, p. 100; Johnson and Gates 2008, p. 456; Hauser and Chenger 2010; Sanders 2010; Mumma and Capouillez 2011, p. 24; Thomson and O'Keefe 2011; Brack et al., unpublished manuscript). Other humanmade features exploited by eastern small-footed bats include rocky dams, road cuts, rocky mine lands, mines, and rock fields within transmission-line and pipeline clearings (Sanders 2011, pers. comm.; Johnson et al

100; Johnson and Gates 2008, p. 456; Hauser and Chenger 2010; Sanders 2010; Mumma and Capouillez 2011, p. 24; Thomson and O'Keefe 2011; Brack et al., unpublished manuscript). Other humanmade features exploited by eastern small-footed bats include rocky dams, road cuts, rocky mine lands, mines, and rock fields within transmission-line and pipeline clearings (Sanders 2011, pers. comm.; Johnson et al. 2011, p. 99; Thomson and O'Keefe 2011). Roost sites are most often located in areas with full solar exposure, but have also been found in areas with moderate to extensive canopy cover (Johnson et al. 2011, p. 100; Brack et al. unpublished manuscript, pp. 9-15; Thomson and O'Keefe 2012). In New Hampshire, eastern small-footed bats have been observed roosting between boulder crevices along the southern outflow of the Surry Mountain Reservoir (Veilleux and Reynolds 2006, p. 330). In Vermont, one summer colony, containing approximately 30 eastern small-footed bats, was located in a slate roof of a house (Darling and Smith 2011, p. 4). Tuttle (1964, p. 149) reported two individuals found in April in Tennessee under a large flat rock at the edge of a quarry surrounded by woods and cow pastures (elevation 549 m (1,800 ft)). In Ontario, a colony of approximately 12 bats was found in July behind a shed door (Hitchcock 1955, p. 31). In addition, small numbers of adult and juvenile eastern small-footed bats have been observed using caves and mines as roosting habitat during the summer months in Maryland, Pennsylvania, Kentucky, Arkansas, West Virginia, and Virginia (Davis et al. 1965, p. 683; Krutzsch 1966, p. 121; Hall and Brenner 1968, p. 779; McDaniel et al. 1982, p. 93; Agosta et al. 2005, p. 1213; Reynolds, pers. comm.).

Summer foraging habitat used by eastern small-footed bats includes rivers, streams, riparian forests, upland forests, clearings, strip mines, and ridgetops (Chenger 2003, pp. 14-23; Chenger 2008a, pp. 10 and 69-71; Chenger 2008b, p. 6; Hauser and Chenger 2010; Johnson et al. 2009, p

; Hall and Brenner 1968, p. 779; McDaniel et al. 1982, p. 93; Agosta et al. 2005, p. 1213; Reynolds, pers. comm.).

Biology

Hibernation

Eastern small-footed bats hibernate during the winter months to conserve energy from increased thermoregulatory demands and reduced food resources. To increase energy savings, individuals enter a state of torpor where internal body temperatures approach ambient temperature, metabolic rates are significantly lowered, and immune function declines (Thomas et al. 1990, p. 475; Thomas and Geiser 1997, p. 585; Bouma et al. 2010, p. 623). Periodic arousal from torpor naturally occurs in all hibernating mammals (Lyman et al. 1982, p. 92), although arousals remain among the least understood of hibernation phenomena (Thomas and Geiser 1997, p. 585). Numerous factors ( e.g., reduction of metabolic waste, body temperature theories, and water balance theory) have been proposed to account for the occurrence and frequency of arousals (Thomas and Geiser 1997, p. 585). Each time a bat arouses from torpor, it uses a significant amount of energy to warm its body and increase its metabolic rate. The cost and number of arousals are the two key factors that determine energy expenditures of hibernating bats in winter (Thomas et al. 1990, p. 475). For example, little brown bats ( Myotis lucifugus ) used as much fat during a typical arousal from hibernation as would be used during 68 days of torpor, and arousals and subsequent activity may constitute 84 percent of the total energy used by hibernating bats during the winter (Thomas et al. 1990, pp. 477-478)

ermine energy expenditures of hibernating bats in winter (Thomas et al. 1990, p. 475). For example, little brown bats ( Myotis lucifugus ) used as much fat during a typical arousal from hibernation as would be used during 68 days of torpor, and arousals and subsequent activity may constitute 84 percent of the total energy used by hibernating bats during the winter (Thomas et al. 1990, pp. 477-478).

Of all hibernating bats, eastern small-footed bats are among the last to enter hibernacula and the first to emerge in the spring (Barbour and Davis 1969, p. 104). Hibernation is approximately mid-November to March (Barbour and Davis 1969, p. 104; Dalton 1987, p. 373); however, there are indications that eastern small-footed bats are active during mild winter weather (Mohr 1936, p. 64; Fenton 1972, p. 5). Fenton (1972, p. 5) observed that when temperatures at hibernation sites rose above 4° Myotis bats (Hitchcock et al. 1984, p. 129). Eastern small-footed bats lose up to 16 percent of their body weights during hibernation (Fenton 1972, p. 5).

Eastern small-footed bats often hibernate solitarily or in small groups and have been found hibernating in the open, in small cracks in cave walls and ceilings, in rock crevices in cave or mine floors, and beneath rocks (Hitchcock 1949, p. 53; Davis 1955, p. 130; Martin et al. 1966, p. 349; Barbour and Davis 1969, p. 104; Banfield 1974, p. 52; Dalton 1987, p. 373). Martin et al. (1966, p. 349) observed up to 30 eastern small-footed bats hanging from the ceilings of two mines in New York. From one small fissure, Hitchcock (1949, p. 53) extracted 35 eastern small-footed bats that were packed so tightly that it appeared almost impossible for those farthest in to get air. This propensity for hibernating in narrow cracks and crevices may mean they are sometimes overlooked by surveyors

. 349) observed up to 30 eastern small-footed bats hanging from the ceilings of two mines in New York. From one small fissure, Hitchcock (1949, p. 53) extracted 35 eastern small-footed bats that were packed so tightly that it appeared almost impossible for those farthest in to get air. This propensity for hibernating in narrow cracks and crevices may mean they are sometimes overlooked by surveyors. In Maryland, for example, far fewer eastern small-footed bats were observed by surveyors during internal hibernacula surveys than were caught in traps during spring emergence (Maryland Department of Natural Resources 2011, unpublished data).

Eastern small-footed bats have been observed hibernating in caves that also contain little brown bats, big brown bats, northern long-eared bats ( Myotis septentrionalis ), Indiana bats ( Myotis sodalis ), tri-colored bats ( Perimyotis subflavus ), Virginia big-eared bats ( Corynorhinus townsendii virginianus ), gray bats ( Myotis grisescens ), and Rafinesque's big-eared bats ( Corynorhinus rafinesquii rafinesquii ), and approximately equal numbers of males and females occupy the same areas and cluster together indiscriminately (Hitchcock 1949, pp. 48-49; Hitchcock 1965, pp. 6-8; Fenton 1972, p. 3; Best and Jennings 1997, p. 3; Hemberger 2011, unpublished data; Graeter 2011, unpublished data; Graham 2011, unpublished data). Fenton (1972, p. 5) commonly observed eastern small-footed bats hibernating in physical contact with big brown bats, usually in small clusters of fewer than five bats, but never close to or in contact with little brown or Indiana bats. Eastern small-footed bats often hibernate in a horizontal position, tucked between cracks and crevices, unlike most Myotis bats, which hang in the open (Merritt 1987, p. 95). When suspended, however, the position of the forearm is unique in that, instead of hanging parallel to the body, as in other Myotis bats, the forearms are somewhat extended (Banfield 1974, p. 52)

little brown or Indiana bats. Eastern small-footed bats often hibernate in a horizontal position, tucked between cracks and crevices, unlike most Myotis bats, which hang in the open (Merritt 1987, p. 95). When suspended, however, the position of the forearm is unique in that, instead of hanging parallel to the body, as in other Myotis bats, the forearms are somewhat extended (Banfield 1974, p. 52). Like most bat species, eastern small-footed bats exhibit high site fidelity to hibernacula, with individuals returning to the same site year after year (Gates et al. 1984, p. 166).

Migration and Homing

Eastern small-footed bats have been observed migrating up to 19 kilometers (km) (12 miles (mi)) (Hitchcock 1955, p. 31) and as little as 0.1 km (0.06 mi) from winter hibernacula to summer roost sites (Johnson and Gates 2008, p. 456). The distance traveled is probably influenced by the availability of hibernacula and roosting sites across the landscape (Johnson and Gates 2008, p. 457). But in general, data suggest that this species hibernates in proximity to its summer range (van Zyll de Jong 1985, p. 119; Divoll et al. 2011). Eastern small-footed bats show a definite homing ability (Best and Jennings 1997, p. 4). Marked bats were present in the same cave in consecutive winters, and when moved to a different cave during the winter, they returned to the original cave the following winter (Mohr 1936, p. 64). In the Mammoth Cave region of Kentucky, eastern small-footed bats are fairly common in late summer in the groups of migrating bats, although the whereabouts of these bats at other seasons is unknown (Barbour and Davis 1969, p. 104).

Summer Roosts

the groups of migrating bats, although the whereabouts of these bats at other seasons is unknown (Barbour and Davis 1969, p. 104).

Summer Roosts

Both males and females change summer roost sites often, even daily, although they typically are moving short distances within a general area (Chenger 2003, pp. 14-23; Johnson et al. 2011, p. 100; Brack et al., unpublished manuscript). Chenger (2009, p. 7) suggests that eastern small-footed bats roost in low numbers over a wide area, such as talus fields, as a predator-avoidance strategy (Chenger 2009, p. 7). Frequent roost-switching may be another means of avoiding potential predators. Johnson et al. 2011 (pp. 98-101) radiotracked five lactating female bats and five nonreproductive males and observed that females and males switched roosts on average every 1.1 days. Males traveled an average of 41 m (135 ft) between consecutive roosts. Females traveled an average of 67 m (218 ft) between consecutive roosts, and roosts were closer to ephemeral water sources than those used by males.

Johnson et al. 2011 (p. 103) hypothesized that roost selection is based on either avoiding detection by predators or minimizing energy expenditures. They observed that roosts were located within 15 m (50 ft) from vegetation or forest edge and in areas with low canopy cover, which consequently provided a short distance to protective cover and high solar exposure. It appears eastern small-footed bats exhibit fidelity to their summer roosting areas, as demonstrated by the recapture of banded bats in successive years at the Surry Mountain Reservoir and Acadia National Park (Divoll et al. 2013; Veilleux and Moosman, unpublished data).

Reproduction

13; Veilleux and Moosman, unpublished data).

Reproduction

Available data regarding the eastern small-footed bat suggest that females of this species form small summer colonies, with males roosting singly or in small groups (Erdle and Hobson 2001, p. 10; Johnson et al. 2011, p. 100). Small maternity colonies of 12 to 20 individuals occurring in buildings have been reported (Merritt 1987, p. 95). Eastern small-footed bats are thought to be similar to sympatric Myotis that breed in the fall; spermatozoa are stored in the uterus of hibernating females until spring ovulation, and a single pup is born in May or June (Barbour and Davis 1969, p. 104; Amelon and Burhans 2006, p. 58). Brack et al. (unpublished manuscript) captured two female eastern small-footed bats in the fall that appeared to have recently mated as noted by fluids around the vagina. Two female eastern small-footed bats caught on June 20 and 24 were pregnant, and 16 female bats caught from June 23 to July 15 were lactating (Brack et al., unpublished manuscript).

Adult longevity is estimated to be up to 12 years in the wild (Hitchcock 1965, p. 11). Estimated mean annual survival is low compared to other Myotis, and survival rates are significantly lower for females than for males, 42 and 75 percent, respectively (Hitchcock et al. 1984, p. 128). The lower rate of survival of females may be a result of a combination of factors: The greater demands of reproduction on females; the higher metabolic rates and less frequent torpor; and the greater exposure to possible disease-carrying parasites in maternity colonies et al. 1984, p. 127). Low survivorship in combination with low reproductive potential ( i.e., one offspring produced per year) (Best and Jennings 1997, p. 2) may explain why eastern small-footed bats are generally uncommon (Hitchcock et al. 1984, p. 129)

males; the higher metabolic rates and less frequent torpor; and the greater exposure to possible disease-carrying parasites in maternity colonies et al. 1984, p. 127). Low survivorship in combination with low reproductive potential ( i.e., one offspring produced per year) (Best and Jennings 1997, p. 2) may explain why eastern small-footed bats are generally uncommon (Hitchcock et al. 1984, p. 129).

Foraging Behavior and Home Range

Eastern small-footed bats have low wing loading and high, frequency-modulated echolocation calls, making them capable of foraging efficiently in cluttered forest interiors (Johnson et al. 2009, p. 5). Although some accounts state that this species emerges early in the evening (van Zyll de Jong 1985, p. 119), Brack et al. (unpublished manuscript) found that activity peaked well after dark, and low post-midnight activities point to the possibility of a bimodal activity period. Most observations indicate that eastern small-footed bats fly slow and close to the ground, usually at heights from 0.6 to 3.5 m (2 to 11.5 ft) (Davis et al. 1965, p. 683; Brack et al., unpublished manuscript).

Using ridgelines, streams, and forested roads as travel corridors, eastern small-footed bats have been observed travelling from 0.8 to 13.2 km (0.5 to 8.2 mi) between daytime roost sites and foraging areas (Chenger 2003, pp. 14-23; Chenger 2008b, p. 6; Johnson et al. 2009, p. 3; Mumma and Capouillez 2011, p. 24). Considerable declines in eastern small-footed bat capture rates have been observed with increasing distance from available rock habitat; and short distances between roosts and capture sites suggest these bats have small home ranges (Johnson et al. 2011, p. 104). Observed home range varies from 10.2 to 1,405 hectares (ha) (25 to 3,472 acres (ac)) (Johnson et al. 2009, p. 3; Mumma and Capouillez 2011, p

iderable declines in eastern small-footed bat capture rates have been observed with increasing distance from available rock habitat; and short distances between roosts and capture sites suggest these bats have small home ranges (Johnson et al. 2011, p. 104). Observed home range varies from 10.2 to 1,405 hectares (ha) (25 to 3,472 acres (ac)) (Johnson et al. 2009, p. 3; Mumma and Capouillez 2011, p. 25), although core habitat for three male and two female eastern small-footed bats ranged from 4 to 75 ha (10 to 185 ac) (50 percent fixed kernel utilization distribution) (Mumma and Capouillez 2011, p. 25).

Food habits of eastern small-footed bats are those of a generalist, although moths (Lepidoptera), true flies (Diptera), and beetles (Coleoptera) compose most of their diet (Johnson and Gates 2007, p. 319; Moosman et al. 2007, p. 355; Brack et al., unpublished manuscript). Presence of spiders (Araneae) and crickets (Gryllidae) in the diet suggest eastern small-footed bats capture some prey via gleaning (Moosman et al. 2007, p. 358). Gleaning behavior is characterized by catching prey on surfaces via echolocation; calls are generally short in duration, high frequency, and of low intensity, characteristics that are difficult for some invertebrate prey to detect (Faure et al. 1993, p. 174).

Species Information

Northern Long-Eared Bat

Taxonomy and Species Description

The northern long-eared bat belongs to the order Chiroptera, suborder Microchiroptera, family Vespertilionidae, subfamily Vesperitilionae, genus Myotis, subgenus Myotis (Caceres and Barclay 2000, p. 1). The northern long-eared bat was considered a subspecies of Keen's long-eared Myotis ( Myotis keenii) (Fitch and Schump 1979, p. 1), but was recognized as a distinct species by van Zyll de Jong in 1979 (1979, p. 993) based on geographic separation and difference in morphology (as cited in Caceres and Pybus 1997 p. 1; Caceres and Barclay 2000, p. 1; Nagorsen and Brigham 1993, p. 87; Whitaker and Hamilton 1998, p. 99; Whitaker and Mumford 2009, p

bspecies of Keen's long-eared Myotis ( Myotis keenii) (Fitch and Schump 1979, p. 1), but was recognized as a distinct species by van Zyll de Jong in 1979 (1979, p. 993) based on geographic separation and difference in morphology (as cited in Caceres and Pybus 1997 p. 1; Caceres and Barclay 2000, p. 1; Nagorsen and Brigham 1993, p. 87; Whitaker and Hamilton 1998, p. 99; Whitaker and Mumford 2009, p. 207; Simmons 2005, p. 516). No subspecies have been described for this species (Nagorsen and Brigham 1993, p. 90; Whitaker and Mumford 2009, p. 214; van Zyll de Jong 1985, p. 94). This species has been recognized by different common names, such as: Keen's bat (Whitaker and Hamilton 1998, p. 99), northern myotis bat (Nagorsen and Brigham 1993, p. 87, Whitaker and Mumford 2009, p. 207), and the northern bat (Foster and Kurta 1999, p. 660). For the purposes of this finding, we refer to this species as the northern long-eared bat, and recognize it as a listable entity under the Act.

A medium-sized bat species, the northern long-eared bat adult body weight averages 5 to 8 g (0.2 to 0.3 ounces), with females tending to be slightly larger than males (Caceres and Pybus 1997, p. 3). Average body length ranges from 77 to 95 mm (3.0 to 3.7 in), tail length between 35 and 42 mm (1.3 to 1.6 in), forearm length between 34 and 38 mm (1.3 to 1.5 in), and wingspread between 228 and 258 mm (8.9 to 10.2 in) (Caceres and Barclay 2000, p. 1; Barbour and Davis 1969, p. 76). Pelage (fur) colors include medium to dark brown on its back, dark brown, but not black, ears and wing membranes, and tawny to pale-brown fur on the ventral side (Nagorsen and Brigham 1993, p. 87; Whitaker and Mumford 2009, p. 207). As indicated by its common name, the northern long-eared bat is distinguished from other Myotis species by its long ears (average 17 mm (0.7 in), Whitaker and Mumford 2009, p. 207) that, when laid forward, extend beyond the nose but less than 5 mm (0.2 in) beyond the muzzle (Caceres and Barclay 2000, p. 1)

r on the ventral side (Nagorsen and Brigham 1993, p. 87; Whitaker and Mumford 2009, p. 207). As indicated by its common name, the northern long-eared bat is distinguished from other Myotis species by its long ears (average 17 mm (0.7 in), Whitaker and Mumford 2009, p. 207) that, when laid forward, extend beyond the nose but less than 5 mm (0.2 in) beyond the muzzle (Caceres and Barclay 2000, p. 1). The tragus (projection of skin in front of the external ear) is long (average 9 mm (0.4 in); Whitaker and Mumford 2009, p. 207), pointed, and symmetrical (Nagorsen and Brigham 1993, p. 87; Whitaker and Mumford 2009, p. 207). Within its range, the northern long-eared bat can be confused with the little brown bat or the western long-eared myotis ( Myotis evotis ). The northern long-eared bat can be distinguished from the little brown bat by its longer ears, tragus, slightly longer tail, and less glossy pelage (Caceres and Barclay 2000, p. 1). The northern long-eared bat can be distinguished from the western long-eared myotis by its darker pelage and paler membranes (Caceres and Barclay 2000, p. 1).

Distribution and Abundance

The northern long-eared bat ranges across much of the eastern and north central United States, and all Canadian provinces west to the southern Yukon Territory and eastern British Columbia (Nagorsen and Brigham 1993, p. 89; Caceres and Pybus 1997, p. 1; Environment Yukon 2011, p. 10). In the United States, the species' range reaches from Maine west to Montana, south to eastern Kansas, eastern Oklahoma, Arkansas, and east to the Florida panhandle (Whitaker and Hamilton 1998, p. 99; Caceres and Barclay 2000, p. 2; Wilson and Reeder 2005, p. 516; Amelon and Burhans 2006, pp. 71-72)

bia (Nagorsen and Brigham 1993, p. 89; Caceres and Pybus 1997, p. 1; Environment Yukon 2011, p. 10). In the United States, the species' range reaches from Maine west to Montana, south to eastern Kansas, eastern Oklahoma, Arkansas, and east to the Florida panhandle (Whitaker and Hamilton 1998, p. 99; Caceres and Barclay 2000, p. 2; Wilson and Reeder 2005, p. 516; Amelon and Burhans 2006, pp. 71-72). The species' range includes the following 39 States (including the District of Columbia, which we count as one of the “States”): Alabama, Arkansas, Connecticut, Delaware, the District of Columbia, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York, North Carolina, North Dakota, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Vermont, Virginia, West Virginia, Wisconsin, and Wyoming. Historically, the species has been most frequently observed in the northeastern United States and in Canadian Provinces, Quebec and Ontario, with sightings increasing during swarming and hibernation (Caceres and Barclay 2000, p. 2). However, throughout the majority of the species' range it is patchily distributed, and historically was less common in the southern and western portions of the range than in the northern portion of the range (Amelon and Burhans 2006, p. 71).

Although they are typically found in low numbers in inconspicuous roosts, most records of northern long-eared bats are from winter hibernacula surveys (Caceres and Pybus 1997, p. 2) (for more information on use of hibernacula, see Biology below). More than 780 hibernacula have been identified throughout the species' range in the United States, although many hibernacula contain only a few (1 to 3) individuals (Whitaker and Hamilton 1998, p. 100)

in inconspicuous roosts, most records of northern long-eared bats are from winter hibernacula surveys (Caceres and Pybus 1997, p. 2) (for more information on use of hibernacula, see Biology below). More than 780 hibernacula have been identified throughout the species' range in the United States, although many hibernacula contain only a few (1 to 3) individuals (Whitaker and Hamilton 1998, p. 100). Known hibernacula (sites with one or more winter records) include: Arkansas (n=20), Connecticut (n=5), Georgia (n=1), Illinois (n=36), Indiana (n=25), Kentucky (n=90), Maine (n=3), Maryland (n=11), Massachusetts (n=7), Michigan (n=94), Minnesota (n=11), Missouri (n=>111), Nebraska (n=2), New Hampshire (n=9), New Jersey (n=8), New York (n=58), North Carolina (n=20), Oklahoma (n=4), Ohio (n=3), Pennsylvania (n=112), South Carolina (n=2), South Dakota (n=7), Tennessee (n=11), Vermont (n=13 (23 historical)), Virginia (n=8), West Virginia (n=104), and Wisconsin (n=45). Other states within the species' range have no known hibernacula (due to no suitable hibernacula present or lack of survey effort). They are typically found roosting in small crevices or cracks on cave or mine walls or ceilings, thus are easily overlooked during surveys and usually observed in small numbers (Griffin 1940, pp. 181-182; Barbour and Davis 1969, p. 77; Caire et al. 1979, p. 405; Van Zyll de Jong 1985, p. 9; Caceres and Pybus 1997, p. 2; Whitaker and Mumford 2009, pp. 209-210).

The U.S. portion of the northern long-eared bat's range can be described in four parts, as discussed below: the eastern population, Midwestern population, the southern population, and the western population.

Eastern Population

ow: the eastern population, Midwestern population, the southern population, and the western population.

Eastern Population

Historically, the northern long-eared bat was most abundant in the eastern portion its range (Caceres and Barclay 2000, p. 2). Northern long-eared bats have been consistently caught during summer mist nets surveys and detected during acoustic surveys in eastern populations. Large numbers of northern long-eared bats have been found in larger hibernacula in Pennsylvania ( e.g., an estimated 881 individuals in a mine in Bucks County, Pennsylvania in 2004). Fall swarm trapping conducted in September-October 1988-1989, 1990-1991, and 1999-2000 at two hibernacula with large historical numbers of northern long-eared bats had total captures ranging from 6 to 30 bats per hour, which demonstrated that the species was abundant at these hibernacula (Pennsylvania Game Commission, unpublished data, 2012).

In Delaware, the species is rare and no hibernacula are documented within the State; however, there is a historical record from Newcastle County in 1970 (Niederriter 2012, pers. comm.). In Connecticut, the northern long-eared bat was historically one of the most commonly encountered bats in the State and had been documented statewide (Dickson 2011, pers. comm.). In Maine, 3 hibernacula are known (all on private land), and the species has also been found in the summer in Acadia National Park (DePue 2012, unpublished data) where northern long-eared bats were found to be fairly common in 2009-2010 (242 northern long-eared bats captured comprising 27 percent of the total captures for the areas surveyed) (NPS 2010).

northern long-eared bats captured comprising 27 percent of the total captures for the areas surveyed) (NPS 2010).

In Maryland, three of seven known hibernacula for the species are railroad tunnels, and no summer mist net or acoustic surveys have been conducted for the species (Feller 2011, unpublished data). In Massachusetts, there are 7 known hibernacula, 42 percent of which are privately owned. In New Hampshire, northern long-eared bats are known to inhabit at least nine mines and two World War II bunkers and have been found in summer surveys, including at Surry Mountain Dam (Brunkhurst 2012, unpublished data). In the White Mountain National Forest in New Hampshire in 1993-1994, northern long-eared was one of the most common species captured (27 percent) (Sasse and Pekins 1996, pp. 93-95). In New Jersey, one of the seven known hibernacula is a cave, and the remainder are mines (Markuson 2011, unpublished data). Northern long-eared bats consisted of 6 to 14 percent of total number of captures at Wallkill River National Wildlife Refuge in New Jersey from 2006-2010 (Kitchell and Wight 2011).

In Vermont, prior to 2009, the species was found in 23 hibernacula, totaling an estimated 595 animals, which was thought to be an under-estimate due to the species' preference for hibernating in hibernacula cracks and crevices. Summer capture data (2001-2007) indicated that northern long-eared bats comprised 19 percent of bats captured; it was considered the second most common bat species in the State (Smith 2011, unpublished data). In Virginia, they were historically considered “fairly common” during summer mist net surveys; however, they are considered “uncommon” during winter hibernacula surveys (Reynolds 2012, unpublished data).

In West Virginia, northern long-eared bats are found regularly in hibernacula surveys, but typically in small numbers (less than 20 individuals) in caves (Stihler 2012, unpublished data)

data). In Virginia, they were historically considered “fairly common” during summer mist net surveys; however, they are considered “uncommon” during winter hibernacula surveys (Reynolds 2012, unpublished data).

In West Virginia, northern long-eared bats are found regularly in hibernacula surveys, but typically in small numbers (less than 20 individuals) in caves (Stihler 2012, unpublished data). The species has also been found in 41 abandoned coal mines in winter surveys conducted from 2002 to 2011 in the New River Gorge National River and Gauley River National Recreation Area, both managed by the National Park Service (NPS); the largest number observed was 157 in one of the NPS mines (NPS 2011, unpublished data). Northern long-eared bats are considered common in summer surveys in West Virginia; in summer records from 2006-2011 northern long-eared bat captures comprised 46 to 49 percent of all bat captures (Stihler 2012, pers. comm.).

Northern long-eared bats have been observed in 58 hibernacula in abandoned mines, caves, and tunnels in New York. They have also been observed in summer mist net and acoustic surveys. Summer mist-net surveys in New York from 2003-2008 resulted in a range of 0.21-0.47 bats/net night and declined to 0.012 bats/net night in 2011 (Herzog 2012, unpublished data). They have also been observed on Fort Drum in New York, where acoustic surveys (2003-2010) and mist net surveys (1999, 2007) have monitored the summer population (Dobony 2011, unpublished data). There are no known hibernacula in Rhode Island; however, there were 6 records from 2011 mist-net surveys in Washington County (Brown 2012, unpublished data).

Midwest Population

11 mist-net surveys in Washington County (Brown 2012, unpublished data).

Midwest Population

The northern long-eared bat is commonly encountered in summer mist-net surveys throughout the majority of the Midwest and is considered fairly common throughout much of the region. However, the species is often found infrequently and in small numbers in hibernacula surveys throughout most of the Midwest. In Missouri, northern long-eared bats were listed as a State species of conservation concern until 2007, after which it was decided the species was more common than previously thought because they were commonly captured in mist net surveys (Elliot 2013, pers. comm.). Historically, the northern long-eared bat was considered quite common throughout much of Indiana, and was the fourth or fifth most abundant bat species in the State in 2009. The species has been captured in at least 51 counties, is often captured in mist-nets along streams, and is the most common bat taken by trapping at mine entrances (Whitaker and Mumford 2009, pp. 207- et al. 2013, p. 193). Indiana has 25 hibernacula with winter records of one or more northern long-eared bats. However, it is very difficult to find individuals in caves and mines during hibernation in large numbers in Indiana hibernacula (Whitaker and Mumford 2009, p. 208).

In Michigan, the northern long-eared bat is known from 25 counties and is not commonly encountered in the State except in parts of the northern Lower Peninsula and portions of the Upper Peninsula (Kurta 1982, p. 301; Kurta 2013, pers. comm.). The majority of hibernacula in Michigan are in the far northern and western Upper Peninsula; therefore, there are very few cave-hibernating bats in general in the southern half of the Lower Peninsula during the summer because the distance to hibernacula is too great (Kurta 2013, pers. comm.). It is thought that the few bats that do spend the summer in the southern half of the Lower Peninsula may hibernate in caves or mines in neighboring states, such as Indiana (Kurta 1982, pp

Peninsula; therefore, there are very few cave-hibernating bats in general in the southern half of the Lower Peninsula during the summer because the distance to hibernacula is too great (Kurta 2013, pers. comm.). It is thought that the few bats that do spend the summer in the southern half of the Lower Peninsula may hibernate in caves or mines in neighboring states, such as Indiana (Kurta 1982, pp. 301-302; Kurta 2013, pers. comm.).

In Wisconsin, the species is reported to be uncommon (Amelon and Burhans 2006, pp. 71-72). “Although the northern long-eared bat can be found in many parts of Wisconsin, it is clearly not abundant in any one location. The department has determined that the Northern long-eared bat is one of the least abundant bats in Wisconsin through cave and mine hibernacula counts, acoustic surveys, mist-netting in summer foraging areas and harp trap captures during the fall swarming period” (Redell 2011, pers. comm.). Northern long-eared bats are regularly caught in mist-net surveys in the Shawnee National Forest in southern Illinois (Kath 2013, pers. comm.). Further, the average number of northern long-eared bats caught during surveys between 1999 and 2011 at Oakwood Bottoms in the Shawnee National Forest has been fairly consistent (Carter 2012, pers. comm.). In Iowa, there are only summer mist net records for the species; in 2011 there were eight records (including three lactating females) from west-central Iowa (Howell 2011, unpublished data). In Minnesota, one mine in St. Louis County may contain a large number of individuals, possibly over 3,000; however, this is a very rough estimate since the majority of the mine cannot be safely accessed for surveys (Nordquist 2012, pers. comm.). In Ohio, there are three known hibernacula and the largest population in Preble County has had more than 300 bats. In general, northern long-eared bats are also regularly collected as incidental catches in mist-net surveys for Indiana bats in Ohio (Boyer 2012, pers. comm.)

s is a very rough estimate since the majority of the mine cannot be safely accessed for surveys (Nordquist 2012, pers. comm.). In Ohio, there are three known hibernacula and the largest population in Preble County has had more than 300 bats. In general, northern long-eared bats are also regularly collected as incidental catches in mist-net surveys for Indiana bats in Ohio (Boyer 2012, pers. comm.).

Southern Population

The northern long-eared bat is less common in the southern portion of its range than in the northern portion of the range (Amelon and Burhans 2006, p. 71) and, in the South, is considered more common in states such as Kentucky and Tennessee, and more rare in the southern extremes of the range ( e.g., Alabama, Georgia, South Carolina). In Alabama, the northern long-eared bat is rare, while in Tennessee it is uncommon (Amelon and Burhans 2006, pp. 71-72). In Tennessee, northern long-eared bats were found in summer mist-net surveys conducted through summer of 2010 in addition to hibernacula censuses. Northern long-eared bats were found in 11 caves surveyed in 2011 in Tennessee (Pelren 2011, pers. comm.). In 2000, during sampling of bat populations in the Kisatchie National Forest, Louisiana, three northern long-eared bat specimens were collected; these were the first official records of the species from Louisiana (Crnkovic 2003, p. 715). In Georgia, northern long-eared bats have been found at 1 of 5 known hibernacula in the State and 24 summer records were found between 2007 and 2011. Mist-net surveys were conducted in the Chattahoochee National Forest in 2001-2002 and 2006-2007, with 51 total records for the species (Morris 2012, unpublished data). Northern long-eared bats have been found in 20 hibernacula within North Carolina (Graeter 2011, unpublished data). In the summer of 2007, (Morris et al. 2009, p. 356) six northern long-eared bats were captured in Washington County, North Carolina

ys were conducted in the Chattahoochee National Forest in 2001-2002 and 2006-2007, with 51 total records for the species (Morris 2012, unpublished data). Northern long-eared bats have been found in 20 hibernacula within North Carolina (Graeter 2011, unpublished data). In the summer of 2007, (Morris et al. 2009, p. 356) six northern long-eared bats were captured in Washington County, North Carolina. Both adults and juveniles were captured, suggesting that there is a reproducing resident population (Morris et al. 2009, p. 359). In Kentucky, although typically found in small numbers, northern long-eared bats were historically found in the majority of hibernacula in Kentucky and have been a commonly captured species during summer surveys (Hemberger 2012, pers. comm.). The northern long-eared bat can be found throughout the majority of Kentucky, with historical records in 91 of its 120 counties. Eighty-five counties have summer records, and 68 of those include reproductive records ( i.e., captures of juveniles or pregnant, lactating, or post-lactating adult females) (Hemberger 2012, pers. comm.). In South Carolina, there are two known hibernacula: one is a cave that had 26 bats present in 1995, but has not been surveyed since, and the other is a tunnel where only one bat was found in 2011 (Bunch 2011, unpublished data). Northern long-eared bats are known from 20 hibernacula in Arkansas, although they are typically found in very low numbers (Sasse 2012, unpublished data). Surveys in the Ouachita Mountains of central Arkansas from 2000-2005 tracked 17 males and 23 females to 43 and 49 day roosts, respectively (Perry and Thill 2007, pp. 221-222). The northern long-eared bat is known to occur in seven counties along the eastern edge of Oklahoma, (Stevenson 1986, p. 41). The species has been recorded in 21 caves (7 of which occur on the Ozark Plateau National Wildlife Refuge) during the summer

ountains of central Arkansas from 2000-2005 tracked 17 males and 23 females to 43 and 49 day roosts, respectively (Perry and Thill 2007, pp. 221-222). The northern long-eared bat is known to occur in seven counties along the eastern edge of Oklahoma, (Stevenson 1986, p. 41). The species has been recorded in 21 caves (7 of which occur on the Ozark Plateau National Wildlife Refuge) during the summer. The species has regularly been captured in summer mist-net surveys at cave entrances in Adair, Cherokee, Sequoyah, Delaware, and LeFlore counties, and are often one of the most common bats captured during mist-net surveys at cave entrances in the Ozarks of northeastern Oklahoma (Stark 2013, pers. comm.). Small numbers of northern long-eared bats (typical range of 1-17 individuals) also have been captured during mist-net surveys along creeks and riparian zones in eastern Oklahoma.

Western Population

The northern long-eared bat is generally less common in the western portion of its range than in the northern portion of the range (Amelon and Burhans 2006, p. 71) and is considered common in only small portions of the western part of its range ( e.g., Black Hills of South Dakota) and uncommon or rare in the western extremes of the range ( e.g., Wyoming, Kansas, Nebraska) (Caceres and Barclay 2000, p. 2). The northern long-eared bat has been observed hibernating and residing during the summer and is considered abundant in the Black Hills National Forest in South Dakota. Capture and banding data for survey efforts in the Black Hills of South Dakota and Wyoming showed northern long-eared bats to be the second most common bat banded (159 of 878 total bats) during 3 years of survey effort (Tigner and Aney

Northern long-eared bats have been observed at two quarries located in east-central Nebraska, but there is no survey data for either of these sites (Geluso 2011, unpublished data)

ng data for survey efforts in the Black Hills of South Dakota and Wyoming showed northern long-eared bats to be the second most common bat banded (159 of 878 total bats) during 3 years of survey effort (Tigner and Aney

Northern long-eared bats have been observed at two quarries located in east-central Nebraska, but there is no survey data for either of these sites (Geluso 2011, unpublished data). They are also known to summer in the northwestern parts of Nebraska, specifically Pine Ridge in Sheridan County (only males have been documented), and a reproducing population has been documented north of Valentine in Cherry County (Benedict et al. 2000, pp. 60-61). During an acoustic survey conducted during the summer of 2012 the species was common in Cass County (east-central Nebraska), but was uncommon or absent from extreme southeastern Nebraska (White et al. 2012, p. 2). The occurrence of this species in Cass County, Nebraska is likely attributable to limestone quarries in the region that are used as hibernacula by this species and others (White et al. 2012, p. 3).

During acoustic and mist net surveys conducted throughout Wyoming in the summers of 2008-2011, 27 separate observations of northern long-eared bats were made in the northeast part of the State and breeding was confirmed (Wyoming Game and Fish Department 2012, unpublished data). To date, there are no known hibernacula in Wyoming and it is unclear if there are existing hibernacula, although the majority of potential hibernacula (abandoned mines) within the State occur outside of the northern long-eared bat's range (Tigner and Stukel 2003, p. 27; Wyoming Game and Fish Department 2012). Montana has only one known record: a male collected in an abandoned coal mine in 1978 in Richland County (Montana Fish, Wildlife, and Parks 2012)

t is unclear if there are existing hibernacula, although the majority of potential hibernacula (abandoned mines) within the State occur outside of the northern long-eared bat's range (Tigner and Stukel 2003, p. 27; Wyoming Game and Fish Department 2012). Montana has only one known record: a male collected in an abandoned coal mine in 1978 in Richland County (Montana Fish, Wildlife, and Parks 2012). In Kansas, the northern long-eared bat was first found in summer mist-net surveys in 1994 and 1995 in Osborne and Russell counties, before which the species was thought to only migrate through parts of the State (Sparks and Choate 1995, p. 190).

Canada Population

The northern long-eared bat occurs throughout the majority of the forested regions of Canada, although it is found in higher abundance in eastern Canada than in western Canada, similar to in the United States (Caceres Pybus 1997, p. 6). However, the scarcity of records in the western parts of Canada may be due to more limited survey efforts. It has been estimated that approximately 40 percent of the northern long-eared bat's global range is in Canada; however, due to the species being relatively common and widespread, limited effort has been made to determine overall population size within Canada (COSEWIC 2012, p.9). The range of the northern long-eared bat in Canada includes Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland and Labrador, Northwest Territories, Nova Scotia, Prince Edward Island, Ontario, Quebec, Saskatchewan, and Yukon (COSEWIC 2012, p. 4). There are no records of the species overwintering in Yukon and Northwest Territories (COSEWIC 2012, p. 9).

Habitat

Winter Habitat

rthwest Territories (COSEWIC 2012, p. 9).

Habitat

Winter Habitat

Northern long-eared bats predominantly overwinter in hibernacula that include caves and abandoned mines. Hibernacula used by northern long-eared bats are typically large, with large passages and entrances (Raesly and Gates 1987, p. 118), relatively constant, cooler temperatures (0 to 9 °C (32 to 48 °F) (Raesly and Gates 1987, p. 18; Caceres and Pybus 1997, p. 2; Brack 2007, p. 744), and with high humidity and no air currents (Fitch and Shump 1979, p. 2; Van Zyll de Jong 1985, p. 94; Raesly and Gates 1987 p. 118; Caceres and Pybus 1997, p. 2). The sites favored by northern long-eared bats are often in very high humidity areas, to such a large degree that droplets of water are often observed on their fur (Hitchcock 1949, p. 52; Barbour and Davis 1969, p. 77). Northern long-eared bats typically prefer cooler and more humid conditions than little brown bats, similar to the eastern small-footed bat and big brown bat, although the latter two species tolerate lower humidity than northern long-eared bats (Hitchcock 1949, p. 52-53; Barbour and Davis 1969, p. 77; Caceres and Pybus 1997, p. 2). Northern long-eared bats are typically found roosting in small crevices or cracks in cave or mine walls or ceilings, often with only the nose and ears visible, thus are easily overlooked during surveys (Griffin 1940, pp. 181-182; Barbour and Davis 1969 p.77; Caire et al. 1979, p. 405; Van Zyll de Jong 1985, p.9; Caceres and Pybus 1997, p. 2; Whitaker and Mumford 2009, pp. 209-210). Caire et al. (1979, p. 405) and Whitaker and Mumford (2009, p. 208) commonly observed individuals exiting caves with mud and clay on their fur, also suggesting the bats were roosting in tighter recesses of hibernacula. They are also found hanging in the open, although not as frequently as in cracks and crevices (Barbour and Davis 1969, p.77, Whitaker and Mumford 2009, pp. 209-210). In 1968, Whitaker and Mumford (2009, pp

05) and Whitaker and Mumford (2009, p. 208) commonly observed individuals exiting caves with mud and clay on their fur, also suggesting the bats were roosting in tighter recesses of hibernacula. They are also found hanging in the open, although not as frequently as in cracks and crevices (Barbour and Davis 1969, p.77, Whitaker and Mumford 2009, pp. 209-210). In 1968, Whitaker and Mumford (2009, pp. 209-210) observed three northern long-eared bats roosting in the hollow core of stalactites in a small cave in Jennings County, Indiana.

To a lesser extent, northern long-eared bats have been found overwintering in other types of habitat that resemble cave or mine hibernacula, including abandoned railroad tunnels, more frequently in the northeast portion of the range. Also, in 1952 three northern long-eared bats were found hibernating near the entrance of a storm sewer in central Minnesota (Goehring 1954, p. 435). Kurta and Teramino (1994, pp. 410-411) found northern long-eared bats hibernating in a hydro-electric dam facility in Michigan. In Massachusetts, northern long-eared bats have been found hibernating in the Sudbury Aqueduct, a structure created in the late 1800s to transfer water, but that is rarely used for this purpose today (French 2012, unpublished data). Griffin (1945, p. 22) found northern long-eared bats in December in Massachusetts in a dry well, and commented that these bats may regularly hibernate in “unsuspected retreats” in areas where caves or mines are not present.

Summer Habitat

During the summer, northern long-eared bats typically roost singly or in colonies underneath bark or in cavities or crevices of both live trees and snags (Sasse and Perkins 1996, p. 95; Foster and Kurta 1999, p. 662; Owen et al. 2002, p. 2; Carter and Feldhamer 2005, p. 262; Perry and Thill 2007, p. 222; Timpone et al. 2010, p. 119). Males and non-reproductive females' summer roost sites may also include cooler locations, including caves and mines (Barbour and Davis 1969, p. 77; Amelon and Burhans 2006, p. 72)

crevices of both live trees and snags (Sasse and Perkins 1996, p. 95; Foster and Kurta 1999, p. 662; Owen et al. 2002, p. 2; Carter and Feldhamer 2005, p. 262; Perry and Thill 2007, p. 222; Timpone et al. 2010, p. 119). Males and non-reproductive females' summer roost sites may also include cooler locations, including caves and mines (Barbour and Davis 1969, p. 77; Amelon and Burhans 2006, p. 72). Northern long-eared bats have also been observed roosting in et al. 2010, p. 119; Joe Kath 2013, pers. comm.).

The northern long-eared bat appears to be somewhat opportunistic in tree roost selection, selecting varying roost tree species and types of roosts throughout its range, including tree species such as black oak ( Quercus velutina ), northern red oak ( Quercus rubra ), silver maple ( Acer saccharinum ), black locust ( Robinia pseudoacacia ), American beech ( Fagus grandifolia ), sugar maple ( Acer saccharum ), sourwood ( Oxydendrum arboreum ), and shortleaf pine ( Pinus echinata ) ( e.g., Mumford and Cope 1964, p. 72; Clark et al. 1987, p. 89; Sasse and Pekins 1996, p. 95; Foster and Kurta 1999, p. 662; Lacki and Schwierjohann 2001, p. 484; Owen et al. 2002, p. 2; Carter and Feldhamer 2005, p. 262; Perry and Thill 2007, p. 224; Timpone et al. 2010, p. 119). Northern long-eared bats most likely are not dependent on a certain species of trees for roosts throughout their range; rather, certain tree species will form suitable cavities or retain bark and the bats will use them opportunistically (Foster and Kurta 1999, p. 668). Carter and Felhamer (2005, p. 265) speculated that structural complexity of habitat or available roosting resources are more important factors than the actual tree species.

ilable roosting resources are more important factors than the actual tree species.

Many studies have documented the northern long-eared bat's selection of live trees and snags, with a range of 10 to 53 percent selection of live roosts found (Sasse and Perkins 1996, p. 95; Foster and Kurta 1999, p. 668; Lacki and Schwierjohann 2001, p. 484; Menzel et al. 2002, p. 107; Carter and Feldhamer 2005, p. 262; Perry and Thill 2007, p. 224; Timpone et al. 2010, p. 118). Foster and Kurta (1999, p. 663) found 53 percent of roosts in Michigan were in living trees, whereas in New Hampshire, 34 percent of roosts were in snags (Sasse and Pekins 1996, p. 95). The use of live trees versus snags may reflect the availability of such structures in study areas (Perry and Thill 2007, p. 224) and the flexibility in roost selection when there is a sympatric bat species present ( e.g., Indiana bat) (Timpone et al. 2010, p. 120). In tree roosts, northern long-eared bats are typically found beneath loose bark or within cavities and have been found to use both exfoliating bark and crevices to a similar degree for summer roosting habitat (Foster and Kurta 1999, p. 662; Lacki and Schwierjohann 2001, p. 484; Menzel et al. 2002, p. 110; Owen et al. 2002, p. 2; Perry and Thill 2007, p. 222; Timpone et al. 2010, p. 119).

Canopy coverage at northern long-eared bat roosts has ranged from 56 percent in Missouri (Timone et al. 2010, p. 118), 66 percent in Arkansas (Perry and Thill 2007, p. 223), greater than 75 percent in New Hampshire (Sasse and Pekins 1996, p. 95), to greater than 84 percent in Kentucky (Lacki and Schwierjohann 2001, p. 487). Studies in New Hampshire and British Columbia have found that canopy coverage around roosts is lower than in available stands (Caceres 1998; Sasse and Pekins 1996, p. 95). Females tend to roost in more open areas than males, likely due to the increased solar radiation, which aids pup development (Perry and Thill 2007, p. 224)

ater than 84 percent in Kentucky (Lacki and Schwierjohann 2001, p. 487). Studies in New Hampshire and British Columbia have found that canopy coverage around roosts is lower than in available stands (Caceres 1998; Sasse and Pekins 1996, p. 95). Females tend to roost in more open areas than males, likely due to the increased solar radiation, which aids pup development (Perry and Thill 2007, p. 224). Fewer trees surrounding maternity roosts may also benefit juvenile bats that are starting to learn to fly (Perry and Thill 2007, p. 224). However, in southern Illinois, northern long-eared bats were observed roosting in areas with greater canopy cover than in random plots (Carter and Feldhamer 2005, p. 263). Roosts are also largely selected below the canopy, which could be due to the species' ability to exploit roosts in cluttered environments; their gleaning behavior suggests an ability to easily maneuver around obstacles (Foster and Kurta 1999, p. 669; Menzel et al. 2002, p. 112).

Female northern long-eared bats typically roost in tall, large-diameter trees (Sasse and Pekins 1996, p. 95). Studies have found that the diameter-at-breast height (dbh) of northern long-eared bat roost trees was greater than random trees (Lacki and Schwierjohann 2001, p. 485) and others have found both dbh and height of selected roost trees to be greater than random trees (Sasse and Pekins 1996, p. 97; Owen et al. 2002 p. 2). However, other studies have found that roost tree mean dbh and height did not differ from random trees (Menzel et al. 2002, p. 111; Carter and Feldhamer 2005, p. 266). Lacki and Schwierjohann (2001, p. 486) have also found that northern long-eared bats roost more often on upper and middle slopes than lower slopes, which suggests a preference for higher elevations due to increased solar heating

2). However, other studies have found that roost tree mean dbh and height did not differ from random trees (Menzel et al. 2002, p. 111; Carter and Feldhamer 2005, p. 266). Lacki and Schwierjohann (2001, p. 486) have also found that northern long-eared bats roost more often on upper and middle slopes than lower slopes, which suggests a preference for higher elevations due to increased solar heating.

Biology

Hibernation

Similar to the eastern small-footed bat description above, the northern long-eared bats hibernate during the winter months to conserve energy from increased thermoregulatory demands and reduced food resources. In general, northern long-eared bats arrive at hibernacula in August or September, enter hibernation in October and November, and leave the hibernacula in March or April (Caire et al. 1979, p. 405; Whitaker and Hamilton 1998, p. 100; Amelon and Burhans 2006, p. 72). However, hibernation may begin as early as August (Whitaker and Rissler 1992, p. 56). In Copperhead Cave in west-central Indiana, the majority of bats enter hibernation during October, and spring emergence occurs mainly from about the second week of March to mid-April (Whitaker and Mumford 2009, p. 210). In Indiana, northern long-eared bats become more active and start feeding outside the hibernaculum in mid-March, evidenced by stomach and intestine contents. This species also showed spring activity earlier than little brown bats and tri-colored bat (Whitaker and Rissler 1992, pp. 56-57). In northern latitudes, such as in upper Michigan's copper-mining district, hibernation for northern long-eared bats and other myotis species may begin as early as late August and may last for 8 to 9 months (Stones and Fritz, 1969, p. 81; Fitch and Shump 1979, p. 2). Northern long-eared bats have shown a high degree of philopatry (using the same site multiple years) for a hibernaculum (Pearson 1962, p. 30), although they may not return to the same hibernaculum in successive seasons (Caceres and Barclay 2000, p. 2)

d other myotis species may begin as early as late August and may last for 8 to 9 months (Stones and Fritz, 1969, p. 81; Fitch and Shump 1979, p. 2). Northern long-eared bats have shown a high degree of philopatry (using the same site multiple years) for a hibernaculum (Pearson 1962, p. 30), although they may not return to the same hibernaculum in successive seasons (Caceres and Barclay 2000, p. 2).

Typically, northern long-eared bats are not abundant and compose a small proportion of the total number of bats hibernating in a hibernaculum (Barbour and Davis 1969, p. 77; Mills 1971, p. 625; Caire et al. 1979, p. 405; Caceres and Barclay 2000, pp. 2-3). Although usually found in small numbers, the species typically inhabits the same hibernacula with large numbers of other bat species, and occasionally are found in clusters with these other bat species. Other species that commonly occupy the same habitat include: little brown bat, big brown bat, eastern small-footed bat, tri-colored bat, and Indiana bat (Swanson and Evans 1936, p. 39; Griffin 1940, p. 181; Hitchcock 1949, pp. 47-58; Stones and Fritz 1969, p. 79; Fitch and Shump 1979, p. 2). Whitaker and Mumford (2009, pp. 209-210), however, infrequently found northern long-eared bats hibernating beside little brown bats, Indiana bats, or tri-colored bats, since they found few hanging on side walls or ceilings of cave passages. Barbour and Davis (1969, p. 77) found that the

Northern long-eared bats often move between hibernacula throughout the winter, which may further decrease population estimates (Griffin 1940, p. 185; Whitaker and Rissler 1992b, p. 131; Caceres and Barclay 2000 pp. 2-3). Whitaker and Mumford (2009, p. 210) found that this species flies in and out of some of the mines and caves in southern Indiana throughout the winter. In particular, the bats were active at Copperhead Cave periodically all winter, with northern long-eared bats being more active than other species (such as little brown bat and tri-colored bat) hibernating in the cave

eres and Barclay 2000 pp. 2-3). Whitaker and Mumford (2009, p. 210) found that this species flies in and out of some of the mines and caves in southern Indiana throughout the winter. In particular, the bats were active at Copperhead Cave periodically all winter, with northern long-eared bats being more active than other species (such as little brown bat and tri-colored bat) hibernating in the cave. Though northern long-eared bats fly outside of the hibernacula during the winter, they do not feed; hence the function of this behavior is not well understood (Whitaker and Hamilton 1998, p. 101). However, it has been suggested that bat activity during winter could be due in part to disturbance by researchers (Whitaker and Mumford 2009, pp. 210-211).

Northern long-eared bats exhibited significant weight loss during hibernation. In southern Illinois, weight loss during hibernation was found in male northern long-eared bats, with individuals weighing an average of 6.6 g (0.2 ounces) prior to 10 January, and those collected after that date weighing an average of 5.3 g (0.2 ounces) (Pearson 1962, p. 30). Whitaker and Hamilton (1998, p. 101) reported a weight loss of 41-43 percent over the hibernation period for northern long-eared bats in Indiana. In eastern Missouri, male northern long-eared bats lost an average of 3 g (0.1 ounces) during the hibernation period (late October through March), and females lost an average of 2.7 g (0.1 ounces) (Caire et al. 1979, p. 406).

Migration and Homing

While the northern long-eared bat is not considered a long-distance migratory species, short migratory movements between summer roost and winter hibernacula between 56 km (35 mi) and 89 km (55 mi) have been documented (Nagorsen and Brigham 1993 p. 88; Griffith 1945, p. 53). However, movements from hibernacula to summer colonies may range from 8 to 270 km (5 to 168 mi) (Griffin 1945, p. 22)

oming

Several studies show a strong homing ability of northern long-eared bats in terms of return rates to a specific hibernaculum, although bats may not return to the same hibernaculum in successive winters (Caceres and Barclay 2000, p. 2). Banding studies in Ohio, Missouri, and Connecticut show return rates to hibernacula of 5.0 percent (Mills 1971, p. 625), 4.6 percent (Caire et al. 1979, p. 404), and 36 percent (Griffin 1940, p. 185), respectively. An experiment showed an individual bat returned to its home cave up to 32 km (20 mi) away after being removed 3 days prior (Stones and Branick 1969, p. 158). Individuals have been known to travel between 56 and 97 km (35 and 60 mi) between caves during the spring (Caire et al. 1979, p. 404; Griffin 1945, p. 20).

Summer Roosts

Northern long-eared bats switch roosts often (Sasse and Perkins 1996, p. 95), typically every 2-3 days (Foster and Kurta 1999, p. 665; Owen et al. 2002, p. 2; Carter and Feldhamer 2005, p. 261; Timpone et al. 2010, p. 119). In Missouri, the longest time spent roosting in one tree was 3 nights; however, the up to 11 nights spent roosting in a humanmade structure has been documented (Timpone et al. 2010, p. 118). Similarly, Carter and Feldhamer (2005, p. 261) found that the longest a northern long-eared bat used the same tree was 3 days; in West Virginia, the average time spent at one roost was 5.3 days (Menzel et al. 2002, p. 110). Bats switch roosts for a variety of reasons, including, temperature, precipitation, predation, parasitism, and ephemeral roost sites (Carter and Feldhamer 2005, p. 264)

. 118). Similarly, Carter and Feldhamer (2005, p. 261) found that the longest a northern long-eared bat used the same tree was 3 days; in West Virginia, the average time spent at one roost was 5.3 days (Menzel et al. 2002, p. 110). Bats switch roosts for a variety of reasons, including, temperature, precipitation, predation, parasitism, and ephemeral roost sites (Carter and Feldhamer 2005, p. 264). Ephemeral roost sites, with the need to proactively investigate new potential roost trees prior to their current roost tree becoming uninhabitable ( e.g., tree falls over), may be the most likely scenario (Kurta et al. 2002, p. 127; Carter and Feldhamer 2005, p. 264; Timpone et al. 2010, p. 119). In Missouri, Timpone et al. (2010, p. 118) radiotracked 13 northern long-eared bats to 39 roosts and found the mean distance between the location where captured and roost tree was 1.7 km (1.1 mi) (range 0.07-4.8 km (0.04-3.0 mi), and the mean distance traveled between roost trees was 0.67 km (0.42 mi) (range 0.05-3.9 km (0.03-2.4 mi)). In Michigan, the longest distance the same bat moved between roosts was 2 km (1.2 mi) and the shortest was 6 m (20 ft) (Foster and Kurta 1999, p. 665). In New Hampshire, the mean distance between foraging areas and roost trees was 602 m (1975 ft) (Sasse and Pekins 1996, p. 95). In the Ouachita Mountains of Arkansas, Perry and Thill (2007, p. 22) found that individuals moved among snags that were within less than 2 ha (5 ac).

Some studies have found tree roost selection to differ slightly between male and female northern long-eared bats. Male northern long-eared bats have been found to more readily use smaller diameter trees for roosting than females, suggesting males are more flexible in roost selection than females (Lacki and Schwierjohann 2001, p. 487; Broders and Forbes 2004, p. 606; Perry and Thill 2007, p. 224). In the Ouachita Mountains of Arkansas, both sexes primarily roosted in snags, although females roosted in snags surrounded by fewer midstory trees than did males (Perry and Thill 2007, p. 224). In New Brunswick, Canada, Broders and Forbes (2004, pp. 606-607) found that there was spatial segregation between male and female roosts, with female maternity colonies typically occupying more mature, shade-tolerant deciduous tree stands and males occupying more conifer-dominated stands. In northeastern Kentucky, males do not use colony roosting sites and are typically found occupying cavities in live hardwood trees, while females form colonies more often in both hardwood and softwood snags (Lacki and Schwierjohann 2001, p. 486).

The northern long-eared bat is comparable to the Indiana bat in terms of summer roost selection, but appears to be more opportunistic (Carter and Feldhamer 2005, pp. 265-266; Timpone et al. 2010, p. 120-121). In southern Michigan, northern long-eared bats used cavities within roost trees, living trees, and roosts with greater canopy cover more often than does the Indiana bat, which occurred in the same area (Foster and Kurta 1999, p. 670). Similarly, in northeastern Missouri, Indiana bats typically roosted in snags with exfoliating bark and low canopy cover, whereas northern long-eared bats used the same habitat in addition to live trees, shorter trees, and trees with higher canopy cover (Timpone et al. 2010 pp. 118-120)

nopy cover more often than does the Indiana bat, which occurred in the same area (Foster and Kurta 1999, p. 670). Similarly, in northeastern Missouri, Indiana bats typically roosted in snags with exfoliating bark and low canopy cover, whereas northern long-eared bats used the same habitat in addition to live trees, shorter trees, and trees with higher canopy cover (Timpone et al. 2010 pp. 118-120). Although northern long-eared bats are more opportunistic than Indiana bats, there may be a small amount of roost selection overlap between the two species (Foster and Kurta 1999, p. 670; Timpone et al. 2010, pp. 120-121).

Reproduction

Breeding occurs from late July in northern regions to early October in southern regions and commences when males begin to swarm hibernacula and initiate copulation activity (Whitaker and Hamilton 1998, p. 101; Whitaker and Mumford 2009, p. 210; Caceres and Barclay 2000, p. 2; Amelon and Burhans 2006, p. 69). Copulation occasionally occurs again in the spring (Racey 1982, p. 73). Hibernating females store sperm until spring, exhibiting a delayed fertilization strategy (Racey 1979, p. et al. 1979, p. 407; Amelon and Burhans 2006, p. 69).

Maternity colonies, consisting of females and young, are generally small, numbering from about 30 (Whitaker and Mumford 2009, p. 212) to 60 individuals (Caceres and Barclay 2000, p. 3); however, one group of 100 adult females was observed in Vermilion County, Indiana (Whitaker and Mumford 2009, p. 212). In West Virginia, maternity colonies in two studies had a range of 7-88 individuals (Owen et al. 2002, p. 2) and 11-65 individuals, with a mean size of 31 (Menzel et al. 2002, p. 110). Lacki and Schwierjohann (2001, p. 485) found that the population size of colony roosts declined as the summer progressed with pregnant females using the largest colonies (mean=26) and post-lactating females using the smallest colonies (mean=4), with the largest overall reported colony size of 65 bats

wen et al. 2002, p. 2) and 11-65 individuals, with a mean size of 31 (Menzel et al. 2002, p. 110). Lacki and Schwierjohann (2001, p. 485) found that the population size of colony roosts declined as the summer progressed with pregnant females using the largest colonies (mean=26) and post-lactating females using the smallest colonies (mean=4), with the largest overall reported colony size of 65 bats. Other studies have also found that the number of individuals within a maternity colony typically decreases from pregnancy to post-lactation (Foster and Kurta 1999, p. 667; Lacki and Schwierjohann 2001, p. 485; Garroway and Broders 2007, p. 962; Perry and Thill 2007, p. 224; Johnson et al. 2012, p. 227). Female roost site selection, in terms of canopy cover and tree height, changes depending on reproductive stage; relative to pre- and post-lactation periods, lactating northern long-eared bats have been shown to roost higher in tall trees situated in areas of relatively less canopy cover and tree density (Garroway and Broders 2008, p. 91).

Adult females give birth to a single pup (Barbour and Davis 1969). Birthing within the colony tends to be synchronous, with the majority of births occurring around the same time (Krochmal and Sparks 2007, p. 654). Parturition (birth) likely occurs in late May or early June (Caire et al. 1979, p. 406; Easterla 1968, p. 770; Whitaker and Mumford 2009, p. 213), but may occur as late as July (Whitaker and Mumford 2009, p. 213). Broders et al. (2006, p. 1177) estimated a parturition date of July 20 in New Brunswick. Lactating and post-lactating females were observed in mid-June in Missouri (Caire et al. 1979, p. 407), July in New Hampshire and Indiana (Sasse and Pekins 1996, p. 95; Whitaker and Mumford 2009, p. 213), and August in Nebraska (Benedict 2004, p. 235). Juvenile volancy (flight) occurs by 21 days after parturition (Krochmal and Sparks 2007, p. 651, Kunz 1971, p. 480) and as early as 18 days after parturition (Krochmal and Sparks 2007, p. 651)

erved in mid-June in Missouri (Caire et al. 1979, p. 407), July in New Hampshire and Indiana (Sasse and Pekins 1996, p. 95; Whitaker and Mumford 2009, p. 213), and August in Nebraska (Benedict 2004, p. 235). Juvenile volancy (flight) occurs by 21 days after parturition (Krochmal and Sparks 2007, p. 651, Kunz 1971, p. 480) and as early as 18 days after parturition (Krochmal and Sparks 2007, p. 651). Subadults were captured in late June in Missouri (Caire et al. 1979, p. 407), early July in Iowa (Sasse and Pekins 1996, p. 95), and early August in Ohio (Mills 1971, p. 625).

Adult longevity is estimated to be up to 18.5 years (Hall 1957, p. 407), with the greatest recorded age of 19 years (Kurta 1995, p. 71). Most mortality for northern long-eared and many other species of bats occurs during the juvenile stage (Caceres and Pybus 1997, p. 4).

Foraging Behavior and Home Range

The northern long-eared bat has a diverse diet including moths, flies, leafhoppers, caddisflies, and beetles (Nagorsen and Brigham 1993, p. 88; Brack and Whitaker 2001, p. 207; Griffith and Gates 1985, p. 452), with diet composition differing geographically and seasonally (Brack and Whitaker 2001, p. 208). Feldhamer et al. (2009, p. 49) noted close similarities of all Myotis diets in southern Illinois, while Griffith and Gates (1985, p. 454) found significant differences in the diets of northern long-eared bat and little brown bat. The most common insects found in the diets of northern long-eared bats are lepidopterans (moths) and coleopterans (beetles) (Feldhamer et al. 2009, p. 45; Brack and Whitaker 2001, p. 207) with arachnids (spiders) also being a common prey item (Feldhamer et al. 2009, p. 45).

rack and Whitaker 2001, p. 207) with arachnids (spiders) also being a common prey item (Feldhamer et al. 2009, p. 45).

Foraging techniques include hawking (catching insects in flight) and gleaning in conjunction with passive acoustic cues (Nagorsen and Brigham 1993, p. 88; Ratcliffe and Dawson 2003, p. 851). Observations of northern long-eared bats foraging on arachnids (Feldhamer et al. 2009, p. 49), presence of green plant material in their feces (Griffith and Gates 1985, p. 456), and non-flying prey in their stomach contents (Brack and Whitaker 2001, p. 207) suggest considerable gleaning behavior. Northern long-eared bats have the highest frequency call of any bat species in the Great Lakes area (Kurta 1995, p. 71). Gleaning allows this species to gain a foraging advantage for preying upon moths because moths are less able to detect these high frequency echolocation calls (Faure et al. 1993, p. 185). Emerging at dusk, most hunting occurs above the understory, 1 to 3 m (3 to 10 ft) above the ground, but under the canopy (Nagorsen and Brigham 1993, p. 88) on forested hillsides and ridges, rather than along riparian areas (Brack and Whitaker 2001, p. 207; LaVal et al. 1977, p. 594). This coincides with data indicating that mature forests are an important habitat type for foraging northern long-eared bats (Caceres and Pybus 1998, p. 2). Occasional foraging also takes place over forest clearings and water, and along roads (Van Zyll de Jong 1985, p. 94). Foraging patterns indicate a peak activity period within 5 hours after sunset followed by a secondary peak within 8 hours after sunset (Kunz 1973, p. 18-19). Brack and Whitaker (2001, p. 207) did not find significant differences in the overall diet of northern long-eared bats between morning (3 a.m. to dawn) and evening (dusk to midnight) feedings; however there were some differences in the consumption of particular prey orders between morning and evening feedings

er sunset followed by a secondary peak within 8 hours after sunset (Kunz 1973, p. 18-19). Brack and Whitaker (2001, p. 207) did not find significant differences in the overall diet of northern long-eared bats between morning (3 a.m. to dawn) and evening (dusk to midnight) feedings; however there were some differences in the consumption of particular prey orders between morning and evening feedings. Additionally, no significant differences existed in dietary diversity values between age classes or sex groups (Brack and Whitaker 2001, p. 208).

Female home range size may range from 19 to 172 ha (47-425 acres) (Lacki et al. 2009, p. 5). Owen et al. (2003, p. 353) estimated average maternal home range size to be 65 ha (161 ac). Home range size of northern long-eared bats in this study site was small relative to other bat species, but this may be due to the study's timing (during the maternity period) and the small body size of M. septentrionalis (Owen et al. 2003, pp. 354-355). The mean distance between roost trees and foraging areas of radio-tagged individuals in New Hampshire was 620 m (2034 ft) (Sasse and Pekins 1996, p. 95).

Summary of Factors Affecting the Species

Section 4 of the Act (16 U.S.C. 1533), and its implementing regulations at 50 CFR part 424, set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of the Act, we may list a species based on any of the following 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; and (E) other natural or manmade factors affecting its continued existence

ay list a species based on any of the following 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; and (E) other natural or manmade factors affecting its continued existence. Listing actions may be warranted based on any of the above threat factors, singly or in

We have carefully assessed the best scientific and commercial information available regarding the past, present, and future threats to the eastern small-footed and northern long-eared bats. Effects to both the eastern small-footed bat and northern long-eared bat from these factors are discussed together where the species are affected similarly.

There are several factors presented below that affect both the eastern small-footed and the northern long-eared bats to a greater or lesser degree; however, we have found that no other threat is as severe and immediate to the northern long-eared bat's persistence as the disease, white-nose syndrome (WNS), discussed below in Factor C. WNS is currently the predominant threat to the species, and if WNS had not emerged or was not affecting the northern long-eared bat populations to the level that it has, we presume the species' would not be experiencing the dramatic declines that it has since WNS emerged. Therefore, although we have included brief discussions of other factors affecting both species, the focus of the discussion below is on WNS.

Factor A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

Hibernation Habitat

tion, Modification, or Curtailment of Its Habitat or Range

Hibernation Habitat

Modifications to bat hibernacula by erecting physical barriers ( e.g., doors, gates) to control cave access and mining can affect the thermal regime of the habitat, and thus the ability of the cave or mine to support hibernating bats, including the northern long-eared and, in some cases, the eastern small-footed bat. For example, the Service's Indiana Bat Draft Recovery Plan (2007, pp. 71-74) presents a discussion of well-documented examples of these type of effectss to cave-hibernating species that are also applicable to our discussion here. Modifications to cave and mine entrances, such as the addition of gates or other structures intended to exclude humans, not only restricts flight and movement (Hemberger 2011, unpublished data), but also changes airflow and alters internal microclimates of the caves and mines and eliminating their utility as hibernacula. For example, Richter et al. (1993, p. 409) attributed the decline in the number of Indiana bats at Wyandotte Cave, Indiana (which harbors one of the largest known population of hibernating Indiana bats), to an increase in the cave's temperature resulting from restricted airflow caused by a stone wall erected at the cave's entrance. After the wall was removed, the number of Indiana bats increased markedly over the next 14 years (Richter et al. 1993, p. 412; Brack et al. 2003, p. 67). In an eastern small-footed bat example, the construction associated with commercializing the Fourth Chute Cave in Ontario, Canada, eliminated the circulation of cold air in one of the unvisited passages where a relatively large number of eastern small-footed bats hibernated. These bats were completely displaced as a result of the warmer microclimate produced (Mohr 1972, p. 36). Correctly installed gates, however, at other locations ( e.g., Aitkin Cave, Pennsylvania) have led to increases in eastern small-footed bat populations (Butchkoski 2012, pers. comm.)

ld air in one of the unvisited passages where a relatively large number of eastern small-footed bats hibernated. These bats were completely displaced as a result of the warmer microclimate produced (Mohr 1972, p. 36). Correctly installed gates, however, at other locations ( e.g., Aitkin Cave, Pennsylvania) have led to increases in eastern small-footed bat populations (Butchkoski 2012, pers. comm.). An example of northern long-eared bats likely being affected occurred when John Friend Cave in Maryland was filled with large rocks in 1981, which closed the only known entrance to the cave (Gates et al. 1984, p. 166).

In addition to the direct access modifications to caves discussed above, debris buildup at entrances or on cave gates can also significantly modify the cave or mine site characteristics through restricting airflow, altering the temperature of hibernacula, and restricting water flow. Water flow restriction could lead to flooding, thus drowning hibernating bats (Amelon and Burhans 2006, p. 72; Hemberger 2011, unpublished data). In Minnesota, 5 of 11 known northern long-eared bat hibernacula are known to flood, presenting a threat to hibernating bats (Nordquist 2012, pers. comm.). In Massachusetts, one of the known hibernacula for northern long-eared bats is a now unused aqueduct that on very rare occasions may fill up with water and make the hibernaculum unusable (French 2012, unpublished data). Flooding has been noted in hibernacula in other States within the range of the northern long-eared bat, but to a lesser degree. Although modifications to hibernacula can lead to mortality of both species, it has not had population-level effects.

Mining operations, mine passage collapse (subsidence), and mine reclamation activities can also affect bats and their hibernacula

12, unpublished data). Flooding has been noted in hibernacula in other States within the range of the northern long-eared bat, but to a lesser degree. Although modifications to hibernacula can lead to mortality of both species, it has not had population-level effects.

Mining operations, mine passage collapse (subsidence), and mine reclamation activities can also affect bats and their hibernacula. Internal and external collapse of abandoned coal mines was identified as one of the primary threats to eastern small-footed and northern long-eared bat hibernacula at sites located within the New River Gorge National River and Gauley River National Recreation Area in West Virginia (Graham 2011, unpublished data). Collapse of hibernacula entrances or areas within the hibernacula, as well as quarry and mining operations that may alter known hibernacula, are considered threats to northern long-eared bats within Kentucky (Hemberger 2011, unpublished data). In States surveyed for effects to northern long-eared bats by hibernacula collapse, responses varied, with the following number of hibernacula in each State reported as susceptible to collapse: 1 (of 7) in Maryland, 3 (of 11) in Minnesota, 1 (of 5) in New Hampshire, 4 (of 15) in North Carolina, 1 (of 2) in South Carolina, and 1 (of 13) in Vermont (Service 2011, unpublished data).

Before current cave protection laws, there were several reported instances where mines were closed while bats were hibernating and entombing entire colonies (Tuttle and Taylor 1998, p. 8). Several caves were historically sealed or mined in Maryland prior to cave protection laws, although bat populations were undocumented (Feller 2011, unpublished data). For both the eastern small-footed and northern long-eared bats, loss of potential winter habitat through mine closures has been noted as a concern in Virginia, although visual inspections of openings are typically conducted to determine whether gating is warranted (Reynolds 2011, unpublished data)

to cave protection laws, although bat populations were undocumented (Feller 2011, unpublished data). For both the eastern small-footed and northern long-eared bats, loss of potential winter habitat through mine closures has been noted as a concern in Virginia, although visual inspections of openings are typically conducted to determine whether gating is warranted (Reynolds 2011, unpublished data). In Nebraska, closing quarries, and specifically sealing quarries in Cass and Sapry Counties, is considered a potential threat to northern long-eared bats (Geluso 2011, unpublished data).

In general, threats to the integrity of bat hibernacula have decreased since the Indiana bat was listed as endangered in 1967, and since the implementation of Federal and State cave protection laws. Increasing awareness about the importance of cave and mine microclimates to hibernating bats and regulation under the Act have helped to alleviate the destruction or modification of hibernation habitat, at least where the Indiana bat is present (Service 2007, p. 74). The eastern small-footed bat and northern long-eared bat have likely benefitted from the protections given to the Indiana bat and its winter habitat, as both species' ranges overlap significantly with the Indiana bat's range.

Disturbance of Hibernating Bats

Human disturbance of hibernating bats has long been considered a threat to cave-hibernating bat species like the eastern small-footed and northern long-eared bats, and is discussed in detail in the Service's Indiana Bat Draft Recovery Plan (2007, pp. 80-85). The primary forms of human disturbance to hibernating bats result from cave commercialization (cave tours and other commercial uses of caves), recreational et al. 1990, p. 477). Human disturbance at hibernacula, specifically non-tactile disturbance such as changes in light and sound, can cause bats to arouse more frequently, causing premature energy store depletion and starvation, as well as increased tactile disturbance of bats to other individuals (Thomas et al

rom cave commercialization (cave tours and other commercial uses of caves), recreational et al. 1990, p. 477). Human disturbance at hibernacula, specifically non-tactile disturbance such as changes in light and sound, can cause bats to arouse more frequently, causing premature energy store depletion and starvation, as well as increased tactile disturbance of bats to other individuals (Thomas et al. 1995, p. 944; Speakman et al. 1991, p. 1103), leading to marked reductions in bat populations (Tuttle 1979, p. 3). Prior to the outbreak of WNS, Amelon and Burhans (2006, p. 73) indicated that “the widespread recreational use of caves and indirect or direct disturbance by humans during the hibernation period pose the greatest known threat to this species (northern long-eared bat).” Olson et al. (2011, p. 228), hypothesized that decreased visits by recreational users and researchers were related to an increase in the hibernating bat population (including northern long-eared bats) at Cadomin Cave in Alberta, Canada. Disturbance during hibernation could cause movements within or between caves (Beer 1955, p. 244).

Human disturbance is a potential threat at approximately half of the known eastern small-footed bat hibernacula in the States of Kentucky, Maryland, North Carolina, Vermont, and West Virginia (Service, unpublished data). Of the States in the northern long-eared bat's range that assessed the possibility of human disturbance at bat hibernacula, 93 percent (13 of 14) identified potential effects from human disturbance for at least 1 of the known hibernacula for this species in their state (Service, unpublished data). Eight of these 14 States (Arkansas, Kentucky, Maine, Minnesota, New Hampshire, North Carolina, South Carolina, and Vermont) indicated the potential for human disturbance at over 50 percent of the known hibernacula in that State

percent (13 of 14) identified potential effects from human disturbance for at least 1 of the known hibernacula for this species in their state (Service, unpublished data). Eight of these 14 States (Arkansas, Kentucky, Maine, Minnesota, New Hampshire, North Carolina, South Carolina, and Vermont) indicated the potential for human disturbance at over 50 percent of the known hibernacula in that State. Nearly all States without WNS identified human disturbance as the primary threat to hibernating bats, and all others (including WNS-positive States) noted human disturbance as a secondary threat (WNS was predominantly the primary threat in these States) or of significant concern (Service, unpublished data).

The threat of commercial use of caves and mines during the hibernation period has decreased at many sites known to harbor Indiana bats, and we believe that this also applies to eastern small-footed and northern long-eared bats. However, effects from recreational caving are more difficult to assess. In addition to unintended effects of commercial and recreational caving, intentional killing of bats in caves by shooting, burning, and clubbing has been documented, although there are no data suggesting that eastern small-footed bats have been killed by these activities (Tuttle 1979, pp. 4, 8). Intentional killing of northern long-eared bats has been documented at a small percentage of hibernacula ( e.g., several cases of vandalism at hibernacula in Kentucky, one case of shooting disturbance in Maryland, one case of bat torching in Massachusetts where approximately 100 bats (northern long-eared bats and other species) were killed) (Service, unpublished data), but we do not have evidence that this is happening on a large enough scale to have population-level effects

percentage of hibernacula ( e.g., several cases of vandalism at hibernacula in Kentucky, one case of shooting disturbance in Maryland, one case of bat torching in Massachusetts where approximately 100 bats (northern long-eared bats and other species) were killed) (Service, unpublished data), but we do not have evidence that this is happening on a large enough scale to have population-level effects.

In summary, while there are isolated incidents of previous disturbance to both bat species due to recreational use of caves in both species, we conclude that there is no evidence suggesting that this threat in itself has led to population declines in either species.

Summer Habitat

Eastern small-footed bats roost in a variety of natural and manmade rock features, whereas northern long-eared bats roost predominantly in trees and to a lesser extent in manmade structures, as discussed in detail in the Species Information section above. We know of only one documented account where vandals were responsible for destroying a portion of an eastern small-footed bat roost located in Maryland (Feller 2011, unpublished data). More commonly, roost habitat for both the eastern small-footed bat and northern long-eared bat is at risk of modification or destruction. In Pennsylvania, for example, highway construction, commercial development, and several wind-energy projects may remove eastern small-footed bat roosting habitat (Librandi-Mumma 2011, pers. comm.). Some of the highest rates of development in the conterminous United States are occurring within the range of eastern small-footed and northern long-eared bats (Brown et al. 2005, p. 1856) and contribute to loss of forest habitat.

n the conterminous United States are occurring within the range of eastern small-footed and northern long-eared bats (Brown et al. 2005, p. 1856) and contribute to loss of forest habitat.

Wind-energy development is rapidly increasing throughout the eastern small-footed bat and northern long-eared bats' ranges, particularly in the States of New Hampshire, New York, Pennsylvania, and Massachusetts. As well, Iowa, Illinois, Minnesota, Oklahoma, and North Dakota are within the top 10 States for wind power capacity (in megawatts) (installed projects) in the United States (American Wind Energy Association 2012, p. 6). If projects are sited in forested habitats, effects from wind-energy development may include forest-clearings associated with turbine placement, road construction, turbine lay-down areas, transmission lines, and substations. In Maryland, wind power development has been proposed in areas with documented eastern small-footed bat and northern long-eared bat summer habitat (Feller 2011, unpublished data). In Pennsylvania, the majority of wind-energy projects are located in habitats characterized as mountain ridge-top, cliffs, steep slopes, or isolated hills with steep, often vertical sides (Mumma and Capouillez 2011, pp. 11-12). Eastern small-footed bats were confirmed through bat mist-net surveys at 7 of 34 proposed wind-energy project sites in Pennsylvania, and northern long-eared bats were confirmed at all 34 proposed wind project sites (Mumma and Capouillez 2011, pp. 62-63). See Factor E. Other Natural or Manmade Factors Affecting Its Continued Existence for a discussion on effects to bats from the operation of wind turbines.

peration of wind turbines.

Another activity that may modify or destroy eastern small-footed bat roosting habitat is mined-land reclamation, whereby rock habitats ( e.g., rock piles, cliffs, spoil piles) are removed from previously mined lands. The Office of Surface Mining Reclamation and Enforcement and its partners are responsible for reclaiming and restoring lands degraded by mining operations. Mining sites eligible for restoration are numerous in the States of Pennsylvania, Ohio, West Virginia, and Kentucky. Reclaiming these sites often involves the removal of exposed rock habitats that may be used as eastern small-footed bat roost habitat (Sanders 2011, pers. comm.). The number of potential roost sites that have been destroyed or that may be destroyed in the future and the potential effect of this destruction on eastern small-footed bat populations are largely unknown. Despite the potential negative effects of this activity, there are no data available suggesting a decrease in the number of eastern small-footed bats from mined-land reclamation activities. Since northern long-eared bats are not known to use exposed rock habitat for roost sites, mined-land reclamation does not affect this species.

Surface coal mining is also common in the central Appalachian region, which includes portions of Pennsylvania, West Virginia, Virginia, Kentucky, and Tennessee, and is one of the major drivers of land cover change in the region (Sayler 2008, unpaginated). Surface coal mining also may destroy forest habitat in parts of the Illinois Basin in southwest Indiana, western Kentucky, and Illinois (King et al. 2010, p. 148). Mountaintop mining involves the clearing of upper elevation forests, stripping of topsoil, and use of explosives to break up rocks to access buried coal. The excess rock is sometimes pushed into adjacent valleys, where it buries existing streams (Palmer et al. 2010, p. 148). Hartman et al. (2005, p

the Illinois Basin in southwest Indiana, western Kentucky, and Illinois (King et al. 2010, p. 148). Mountaintop mining involves the clearing of upper elevation forests, stripping of topsoil, and use of explosives to break up rocks to access buried coal. The excess rock is sometimes pushed into adjacent valleys, where it buries existing streams (Palmer et al. 2010, p. 148). Hartman et al. (2005, p. 96) reported significant reductions in insect densities in streams affected with fill material, including lower densities of coleopterans, a primary food source of eastern small-footed and northern long-eared bats (Griffith and Gates 1985, p. 452; Johnson and Gates 2007, p. 319; Moosman et al. 2007, p. 355; Feldhamer et al. 2009, p. 45). The effect of mountaintop mining on eastern small-footed bat and northern long-eared bat populations is largely unknown.

The effect of forest removal related to the eastern small-footed bat is poorly understood. Forest management can influence the availability and characteristics of non-tree roost sites, such as those used by eastern small-footed bats, although the resulting effects on bats and bat populations are poorly known (Hayes and Loeb 2007, p. 215). Since eastern small-footed bats often forage in forests immediately surrounding roost sites, forest management may affect the quality of foraging habitat (Johnson et al. 2009, p. 5). Scientific evidence and anecdotal observations support the hypotheses that bats respond to prey availability, that prey availability is influenced by forest management, and that influences of forest management on prey populations affect bat populations (Hayes and Loeb 2007, p. 219). In addition, forest management activities that influence tree density directly alter the amount of vegetative clutter ( e.g., tree density) in an area. As a result, forest management can directly influence habitat suitability for bats through changes in the amount of vegetative clutter (Hayes and Loeb 2007, p. 217)

anagement on prey populations affect bat populations (Hayes and Loeb 2007, p. 219). In addition, forest management activities that influence tree density directly alter the amount of vegetative clutter ( e.g., tree density) in an area. As a result, forest management can directly influence habitat suitability for bats through changes in the amount of vegetative clutter (Hayes and Loeb 2007, p. 217). Eastern small-footed bats are capable of foraging in cluttered forest interiors, but as discussed in the Species Information section above, they have also been found foraging in clearings, in strip mine areas, and over water. Johnson and Gates (2008, p. 459) suggest that a better understanding of the required spatial extent and structure of forest cover along ridgelines and rock outcrops, as well as additional foraging activity requirements, is needed to aid conservation efforts for the eastern small-footed bat.

Although there is still much to learn about the effects of forest removal on northern long-eared bats and their associated summer habitat, studies to date have found that the northern long-eared bat shows a varied degree of sensitivity to timber harvesting practices. Several studies (as discussed in the Species Information section above) have found that the species uses a wide range of tree species for roosting, suggesting that forest succession may play a larger role in roost selection (than tree species) (Silvis et al. 2012, p. 6). Studies have found that female bat roosts are more often ( i.e., greater than what would be expected from random chance) located in areas with partial harvesting than in random sites, which may be due to trees located in more open habitat receiving greater solar radiation and therefore speeding development of young (Menzel et al. 2002, p. 112; Perry and Thill 2007, pp. 224-225)

et al. 2012, p. 6). Studies have found that female bat roosts are more often ( i.e., greater than what would be expected from random chance) located in areas with partial harvesting than in random sites, which may be due to trees located in more open habitat receiving greater solar radiation and therefore speeding development of young (Menzel et al. 2002, p. 112; Perry and Thill 2007, pp. 224-225). In the Appalachians of West Virginia, diameter-limit harvests (70-90 year-old stands, with 30-40 percent of the basal area removed in the past 10 years) rather than intact forest was the habitat type most selected by northern long-eared bats (Owen et al. 2003, p. 356). Cryan et al. (2001, p. 49) found several northern long-eared bat roost areas in recently harvested (less than 5 years) stands in the Black Hills of South Dakota, although the largest colony (n=41) was found in a mature forest stand that had not been harvested in over 50 years. In intensively managed forests in the central Appalachians, Owen et al. (2002, p. 4) found roost availability was not a limiting factor for the northern long-eared bat, since bats often chose black locust and black cherry as roost trees, which were quite abundant since these trees often regenerate quickly after disturbance ( e.g., timber harvest).

It is possible that this flexibility in roosting habits allows northern long-eared bats to be adaptable in managed forests, which allows them to avoid competition for roosting habitat with more specialized species, such as the Indiana bat (Timpone et al. 2010, p. 121). However, the northern long-eared bat has shown a preference for contiguous tracts of forest cover for foraging (Owen et al. 2003, p. 356; Yates and Muzika 2006, p. 1245). Jung et al. (2004, p. 333) found that it is important to retain snags and provide for recruitment of roost trees during selective harvesting in forest stands that harbor bats

such as the Indiana bat (Timpone et al. 2010, p. 121). However, the northern long-eared bat has shown a preference for contiguous tracts of forest cover for foraging (Owen et al. 2003, p. 356; Yates and Muzika 2006, p. 1245). Jung et al. (2004, p. 333) found that it is important to retain snags and provide for recruitment of roost trees during selective harvesting in forest stands that harbor bats. If roost networks are disturbed through timber harvesting, there may be more dispersal and fewer shared roost trees, which may lead to less communication between bats in addition to less disease transmission (Johnson et al. 2012, p. 230). In the Appalachians, Ford et al. (2006, p. 20) assessed that northern long-eared bats may be a suitable management indicator species for assessing mature forest ecosystem integrity, since they found male bats using roosts in mature forest stands of mostly second growth or regenerated forests.

There is conflicting information on sensitivities of male versus female northern long-eared bats to forestry practices and resulting fragmentation. In Arkansas, Perry and Thill (2007, p. 225) found that male northern long-eared bats seem to prefer more dense stands for summer roosting, with 67 percent of male roosts occurring in unharvested sites versus 45 percent of female roosts. The greater tendency of females to roost in more open forested areas than males may be due to greater solar radiation experienced in these openings, which could speed growth of young in maternity colonies (Perry and Thill 2007, p. 224). Lacki and Schwierjohann (2001, p. 487) stated that silvicultural practices could meet both male and female roosting requirements by maintaining large-diameter snags, while allowing for regeneration of forests. However, Broders and Forbes (2004, p. 608) found that timber harvest may have negative effects on female bats since they use forest interiors at small scales (less than 2 km (1.2 mi) from roost sites)

Schwierjohann (2001, p. 487) stated that silvicultural practices could meet both male and female roosting requirements by maintaining large-diameter snags, while allowing for regeneration of forests. However, Broders and Forbes (2004, p. 608) found that timber harvest may have negative effects on female bats since they use forest interiors at small scales (less than 2 km (1.2 mi) from roost sites). They also found that males are not as limited in roost selection and they do not have the energetic cost of raising young; therefore males may be less affected than females (Broders and Forbes 2004, p. 608). Henderson et al. (2008, p. 1825) also found that forest fragmentation effects northern long-eared bats at different scales based on sex; females require a larger unfragmented area with a large number of suitable roost trees to support a colony, whereas males are able to use smaller areas (more fragmented). Henderson and Broders (2008, pp. 959-960) examined how female northern long-eared bats use the forest-agricultural landscape on Prince Edward Island, Canada, and found that bats were limited in their mobility and activities are constrained where suitable forest is limited. However, they also found that bats in relatively fragmented areas used a building for colony roosting, which suggests an alternative for a colony to persist in an area with fewer available roost trees. Although we are still learning about the effect of forest removal on northern long-eared

Natural gas development from shale is expanding across the United States, particularly throughout the range of the northern long-eared and eastern small-footed bat. Natural gas extraction involves fracturing rock formations and uses highly pressurized fluids consisting of water and various chemicals to do so (Hein 2012, p. 1). Natural gas extraction, particularly across the Marcellus Shale region, which includes large portions of New York, Pennsylvania, Ohio, and West Virginia, is expected to expand over the coming years

ng-eared and eastern small-footed bat. Natural gas extraction involves fracturing rock formations and uses highly pressurized fluids consisting of water and various chemicals to do so (Hein 2012, p. 1). Natural gas extraction, particularly across the Marcellus Shale region, which includes large portions of New York, Pennsylvania, Ohio, and West Virginia, is expected to expand over the coming years. In Pennsylvania, for example, nearly 2,000 Marcellus natural gas wells have already been drilled or permitted, and as many as 60,000 more could be built by 2030, if development trends continue (Johnson 2010, pp. 8, 13). Habitat loss and degradation due to this practice could occur in the form of forest clearing for well pads and associated infrastructure ( e.g., roads, pipelines, and water impoundments), which would decrease the amount of suitable interior forest habitat available to northern long-eared and eastern small-footed bats for establishing maternity colonies and for foraging, in addition to further isolating populations and, therefore, potentially decreasing genetic diversity (Johnson 2010, p. 10; Hein 2012, p. 6). Since northern long-eared bats and eastern small-footed bats have philopatric tendencies, loss or alteration of forest habitat for natural gas development may also put additional stress on females when returning to summer roost or foraging areas after hibernation if females were forced to find new roosting or foraging areas (expend additional energy) (Hein 2012, pp. 11-12).

Conservation Efforts To Reduce Habitat Destruction, Modification, or Curtailment of Its Range

odification, or Curtailment of Its Range

Although there are various forms of habitat destruction and disturbance that present potential adverse effects to the northern long-eared bat, this is not considered the predominant threat to the species. Even if all habitat-related stressors were eliminated or minimized, the significant effects of WNS on the northern long-eared bat would still be present. Therefore, below we present a few examples, but not a comprehensive list, of conservation efforts that have been undertaken to lessen effects from habitat destruction or disturbance to northern long-eared and eastern small-footed bats. One of the threats to bats in Michigan is the closure of unsafe mines in such a way that bats are trapped within or excluded; however, there have been efforts by the Michigan Department of Natural Resources and others to work with landowners who have open mines to encourage them to install bat-friendly gates to close mines to humans, but allow access to bats (Hoving 2011, unpublished data). The NPS has proactively taken efforts to minimize effects to bat habitat resulting from vandalism, recreational activities, and abandoned mine closures (Plumb and Budde 2011, unpublished data). In addition, the NPS is properly gating, using a “bat-friendly design, abandoned coal mine entrances as funding permits (Graham 2011, unpublished data). All known hibernacula within national grasslands and forestlands of the Rocky Mountain Region of the U.S. Forest Service are closed during the winter hibernation period, primarily due to the threat of white-nose syndrome, although this will reduce disturbance to bats in general inhabiting these hibernacula (U.S. Forest Service 2013, unpaginated). Concern over the importance of bat roosts, including hibernacula, fueled efforts by the American Society of Mammalogists to develop guidelines for protection of roosts, many of which have been adopted by government agencies and special interest groups (Sheffield et al. 1992, p. 707)

his will reduce disturbance to bats in general inhabiting these hibernacula (U.S. Forest Service 2013, unpaginated). Concern over the importance of bat roosts, including hibernacula, fueled efforts by the American Society of Mammalogists to develop guidelines for protection of roosts, many of which have been adopted by government agencies and special interest groups (Sheffield et al. 1992, p. 707).

Summary of the Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

We have identified several activities, such as constructing physical barriers at cave accesses, mining, flooding, vandalism, development, and timber harvest, that may modify or destroy habitat for the eastern small-footed bat and northern long-eared bat. Although such activities occur, these activities alone do not have significant, population-level effects on either species.

Factor B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes

There are very few records of either species being collected specifically for commercial, recreational, scientific, or educational purposes, and thus we do not consider such collection activities to pose a threat to either species. Disturbance of hibernating bats as a result of recreational use and scientific research activities in hibernacula is discussed under Factor A.

Factor C. Disease or Predation

Disease

White-Nose Syndrome

White-nose syndrome is an emerging infectious disease responsible for unprecedented mortality in some hibernating insectivorous bats of the northeastern United States (Blehert et al. 2009, p. 227), and poses a considerable threat to several hibernating bat species throughout North America (Service 2010, p. 1). Since its first documented appearance in New York in 2006, WNS has spread rapidly throughout the Northeast and is expanding through the Midwest

esponsible for unprecedented mortality in some hibernating insectivorous bats of the northeastern United States (Blehert et al. 2009, p. 227), and poses a considerable threat to several hibernating bat species throughout North America (Service 2010, p. 1). Since its first documented appearance in New York in 2006, WNS has spread rapidly throughout the Northeast and is expanding through the Midwest. As of August 2013, WNS has been confirmed in 22 States (Alabama, Connecticut, Delaware, Georgia, Illinois, Indiana, Kentucky, Maine, Maryland, Massachusetts, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Vermont, Virginia, and West Virginia) and 5 Canadian provinces (New Brunswick, Nova Scotia, Ontario, Prince Edward Island, and Quebec). Four additional States (Arkansas, Iowa, Minnesota, and Oklahoma) are considered suspect for WNS based on the detection of the causative fungus on bats within those States, but with no associated disease to date. Service biologists and partners estimate that at least 5.7 million to 6.7 million bats of several species have now died from WNS (Service 2012, p. 1). Dzal et al. (2011, p. 393) documented a 78-percent decline in the summer activity of little brown bats in New York State, coinciding with the arrival and spread of WNS, suggesting large-scale population effects. Turner et al. (2011, p. 22) reported an 88-percent decline in the number of hibernating bats at 42 sites from the States of New York, Pennsylvania, Vermont, Virginia, and West Virginia. Furthermore, Frick et al. (2010, p. 681) predicted that the little brown bat, formerly the most common bat in the northeastern United States, will likely become extinct in the region by 2026 (potential loss of some 6.5 million bats) if current trends continue. Similarly, Thogmartin et al. (2013, p. 171) predicted that WNS is likely to extirpate the federally endangered Indiana bat over large parts of its range

Frick et al. (2010, p. 681) predicted that the little brown bat, formerly the most common bat in the northeastern United States, will likely become extinct in the region by 2026 (potential loss of some 6.5 million bats) if current trends continue. Similarly, Thogmartin et al. (2013, p. 171) predicted that WNS is likely to extirpate the federally endangered Indiana bat over large parts of its range. These predicted trends in little brown bats and Indiana bats may or may not also be indicative of population trends in other bat species like the eastern small-footed and northern long-eared bats.

The first evidence of WNS was documented in a photograph taken from Howes Cavern, 52 km (32 mi) west of et al. 2009, p. 227). Prior to the arrival of WNS, surveys of six species of hibernating bats in New York State revealed that populations had been stable or increasing in recent decades (Service 2010, p. 1). Decreases in some species of bats at WNS-infected hibernacula have ranged from 30 to 99 percent (Frick et al. 2010, p. 680).

The pattern of spread has generally followed predictable trajectories along recognized migratory pathways and overlapping summer ranges of hibernating bat species. Therefore, Kunz and Reichard (2010, p. 12) assert that WNS is spread mainly through bat-to-bat contact; however, evidence suggests that fungal spores can be transmitted by humans (United States Geologic Survey (USGS) National Wildlife Health Center, Wildlife Health Bulletin 2011-05), and bats can also become infected by coming into contact with contaminated cave substrate (Darling 2012, pers. comm.). Six North American hibernating bat species (little brown bat, Indiana bat, northern long-eared bat, eastern small-footed bat, big brown bat, and tri-colored bat), are known to be affected by WNS; however, the effect of WNS varies by species. The fungus that causes WNS has been detected on three additional species; the southeastern bat ( Myotis austroriparius ), and gray bat ( Myotis grisescens ), and cave bat ( Myotis velifer )

bat species (little brown bat, Indiana bat, northern long-eared bat, eastern small-footed bat, big brown bat, and tri-colored bat), are known to be affected by WNS; however, the effect of WNS varies by species. The fungus that causes WNS has been detected on three additional species; the southeastern bat ( Myotis austroriparius ), and gray bat ( Myotis grisescens ), and cave bat ( Myotis velifer ). White-nose syndrome is caused by the recently described psychrophilic (cold-loving) fungus, currently known as Geomyces destructans. Geomyces destructans may be nonnative to North America, and only recently arrived on the continent (Puechmaille et al. 2011, p. 8). The fungus grows on and within exposed tissues of hibernating bats (Lorch et al. 2011, p. 376; Gargas et al. 2009, pp. 147-154)), and the diagnostic feature is the white fungal growth on muzzles, ears, or wing membranes of affected bats, along with epidermal (skin) erosions that are filled with fungal hyphae (branching, filamentous structures of fungi) (Blehert et al. 2009, p. 227; Meteyer 2009, p. 412). Geomyces destructans grows optimally at temperatures from 5 to 10 °C (41 to 50 °F), the same temperatures at which bats typically hibernate (Blehert et al. 2009, p. 227). Temperatures in WNS-affected hibernacula seasonally range from 2 to 14 °C (36 to 57 °F), permitting year-round growth, and may act as a reservoir maintaining the fungus (Blehert et al. 2009, p. 227). Growth is slow, and no growth occurs at temperatures above 24 °C (75 °F) (Gargas et al. 2009, p. 152). Bats that are found in more humid regions of hibernacula may be more susceptible to WNS, but further research is needed to confirm this hypothesis. Declines in Indiana bats have been greater under more humid conditions, suggesting that growth of the fungus and either intensity or prevalence of infections are higher in more humid conditions (Langwig et al. 2012a, p. 1055). Although G

2009, p. 152). Bats that are found in more humid regions of hibernacula may be more susceptible to WNS, but further research is needed to confirm this hypothesis. Declines in Indiana bats have been greater under more humid conditions, suggesting that growth of the fungus and either intensity or prevalence of infections are higher in more humid conditions (Langwig et al. 2012a, p. 1055). Although G. destructans has been isolated from five bat species from Europe, research suggests that bat species in Europe may be immunologically or behaviorally resistant, having coevolved with the fungus (Wibbelt et al. 2010, p. 1241). Pikula et al. (2012, p. 210), however, confirmed that bats found dead in the Czech Republic exhibited lesions consistent with WNS infection.

In addition to the presence of the white fungus, initial observations showed that bats affected by WNS were characterized by some or all of the following: (1) Depleted fat reserves by mid-winter; (2) a general unresponsiveness to human disturbance; (3) an apparent lack of immune response during hibernation; (4) ulcerated, necrotic, and scarred wing membranes; and (5) aberrant behaviors, including shifts of large numbers of bats in hibernacula to roosts near the entrances or unusually cold areas, large numbers of bats dispersing during the day from hibernacula during mid-winter, and large numbers of fatalities, either inside the hibernacula, near the entrance, or in the immediate vicinity of the entrance (WNS Science Strategy Report 2008, p. 2; Service 2010, p. 2). Although the exact process by which WNS leads to death remains undetermined, it is likely that the immune function during torpor compromises the ability of hibernating bats to combat the infection (Bouma et al. 2010, p. 623; Moore et al. 2011, p. 10).

Early hypotheses suggested that WNS may affect bats before the hibernation season begins, causing bats to arrive at hibernacula with insufficient fat to survive the winter

s by which WNS leads to death remains undetermined, it is likely that the immune function during torpor compromises the ability of hibernating bats to combat the infection (Bouma et al. 2010, p. 623; Moore et al. 2011, p. 10).

Early hypotheses suggested that WNS may affect bats before the hibernation season begins, causing bats to arrive at hibernacula with insufficient fat to survive the winter. Alternatively, a second hypothesis suggests that bats arrive at hibernacula unaffected and enter hibernation with sufficient fat stores, but then become affected and use fat stores too quickly as a result of disruption to hibernation physiology (WNS Science Strategy Group 2008, p. 7). More recent observations, however, suggest that bats are arriving to hibernacula with sufficient or only slightly lower fat stores (Turner 2011, pers. comm.), and that although body weights of WNS-infected bats were consistently at the lower end of the normal range, in one study 12 of 14 bats (10 little brown bats, 1 big-brown bat, and 1 tri-colored bat) had an appreciable degree of fat stores (Courtin et al. 2010, p. 4).

Boyles and Willis (2010, pp. 92-98) hypothesized that infection by Geomyces destructans alters the normal arousal cycles of hibernating bats, particularly by increasing arousal frequency, duration, or both. In fact, Reeder et al. (2012, p. 5) and Warnecke et al. (2012, p. 2) did observe an increase in arousal frequency in laboratory studies of hibernating bats infected with G. destructans. A disruption of this torpor-arousal cycle could easily cause bats to metabolize fat reserves too quickly, thereby leading to starvation. For example, skin irritation from the fungus might cause bats to remain out of torpor for longer than normal to groom, thereby exhausting their fat reserves prematurely (Boyles and Willis 2010, p. 93).

Due to the unique physiological importance of wings to hibernating bats in relation to the damage caused by Geomyces destructans, Cryan et al. (2010, pp

too quickly, thereby leading to starvation. For example, skin irritation from the fungus might cause bats to remain out of torpor for longer than normal to groom, thereby exhausting their fat reserves prematurely (Boyles and Willis 2010, p. 93).

Due to the unique physiological importance of wings to hibernating bats in relation to the damage caused by Geomyces destructans, Cryan et al. (2010, pp. 1-8) suggests that mortality may be caused by catastrophic disruption of wing-dependent physiological functions. The authors hypothesize that G. destructans may cause unsustainable dehydration in water-dependent bats, trigger thirst-associated arousals, cause significant circulatory and thermoregulatory disturbance, disrupt respiratory gas exchange, and destroy wing structures necessary for flight control (Cryan et al. 2010, p. 7). The wings of winter-collected WNS-affected bats often reveal signs of infection, whereby the degree of damage observed suggests functional impairment. Emaciation is a common finding in bats that have died from WNS (Cryan et al. 2010, p. 3). Cryan et al. (2010, p. 3) hypothesized that disruption of physiological homeostasis, potentially caused by G. destructans infection, may be sufficient to result in emaciation and mortality. The authors hypothesized that wing damage caused by G. destructans infections could sufficiently disrupt water balance to trigger frequent thirst-associated arousals with excessive winter flight, and subsequent premature depletion of fat stores. In related research, Cryan et al. (2013, p. 398) found, after analyzing blood from hibernating bats infected with WNS, that electrolytes, sodium and chloride, tended to decrease as wing damage increased in severity. Proper concentrations of electrolytes are necessary for maintaining physiologic homeostasis, and any imbalance could be life-threatening (Cryan et al. 2013, p. 398)

tion of fat stores. In related research, Cryan et al. (2013, p. 398) found, after analyzing blood from hibernating bats infected with WNS, that electrolytes, sodium and chloride, tended to decrease as wing damage increased in severity. Proper concentrations of electrolytes are necessary for maintaining physiologic homeostasis, and any imbalance could be life-threatening (Cryan et al. 2013, p. 398). Although the exact mechanism by which WNS affects bats is still in

Effects of White-Nose Syndrome on the Eastern Small-Footed Bat

Eastern small-footed bats are known to be susceptible to WNS. As of 2011, of the 283 documented eastern small-footed bat hibernacula, 86 (31 percent) were WNS-positive (Service 2011, unpublished data). Only three eastern small-footed bats have been collected, tested, and confirmed positive for WNS by histology: One bat collected and euthanized from New York in 2009, one bat found dead in Pennsylvania in 2011, and one bat found dead from South Carolina in 2013 (Ballmann 2011, pers. comm.; Last 2013a, pers. comm.). An additional eastern small-footed bat collected in winter 2011-2012 from the Mammoth Cave Visitor Center in Kentucky, was submitted to the Southeastern Cooperative Wildlife Disease Study; however, this bat tested negative for WNS. Biologists also observed approximately five dead eastern small-footed bats with obvious signs of fungal infection in Virginia (Reynolds 2011, pers. comm.).

To determine whether WNS is causing a population-level effect to eastern small-footed bats, the Service began by reviewing winter hibernacula survey data. By comparing the most recent pre-WNS count to the most recent post-WNS count, Turner et al. (2011, p. 22) reported a 12-percent decline in the number of hibernating eastern small-footed bats at 25 hibernacula in New York, Pennsylvania, Vermont, Virginia, and West Virginia. Data analyzed in this study were limited to sites with confirmed WNS mortality for at least 2 years and sites with comparable survey effort across pre- and post-WNS years

o the most recent post-WNS count, Turner et al. (2011, p. 22) reported a 12-percent decline in the number of hibernating eastern small-footed bats at 25 hibernacula in New York, Pennsylvania, Vermont, Virginia, and West Virginia. Data analyzed in this study were limited to sites with confirmed WNS mortality for at least 2 years and sites with comparable survey effort across pre- and post-WNS years. Based on a review of pre-WNS hibernacula count data over multiple years at 12 of these sites, the number of eastern small-footed bats fluctuated between years.

When we compared the most recent post-WNS eastern small-footed bat count to pre-WNS observations, we found that post-WNS counts were within the normal observed range at nine sites (75 percent), higher at two sites (17 percent), and lower at only one site (8 percent). In addition, although Langwig et al. (2012a, p. 1052) reported a significantly lower population growth rate compared to pre-WNS population growth rates for eastern small-footed bat, they found that the species was not declining significantly at hibernacula in New York, Vermont, Connecticut, and Massachusetts. Langwig et al. (2012b, p. 15) also observed lower prevalence of Geomyces destructans on eastern small-footed bat wing and muzzle tissue during late hibernation, compared to other bat species ( e.g., little brown bats). Lastly, biologists did not observe fungal growth (although the fungus may not be visible after the first couple of years) on eastern small-footed bats during 2013 hibernacula surveys in New York, Pennsylvania, and North Carolina, even though it was observed on other bat species ( e.g., little brown bats) within the same sites (although a few, not all, eastern small-footed bats viewed under ultraviolet light did show signs of mild infections), nor did they observe reduced numbers of eastern small-footed bats compared to pre-WNS years (Graeter 2013, pers. comm.; Herzog 2013, pers. comm.; Turner 2013, unpublished data)

olina, even though it was observed on other bat species ( e.g., little brown bats) within the same sites (although a few, not all, eastern small-footed bats viewed under ultraviolet light did show signs of mild infections), nor did they observe reduced numbers of eastern small-footed bats compared to pre-WNS years (Graeter 2013, pers. comm.; Herzog 2013, pers. comm.; Turner 2013, unpublished data). In fact, biologists in New York observed the largest number of hibernating eastern small-footed bats ever reported (2,383) during surveys conducted in 2013, up from 1,727 reported in 1993 using roughly comparable survey effort (Herzog 2013, pers. comm.). In summary, WNS does not appear to have caused a significant population decline in hibernating eastern small-footed bats.

Summer survey data are limited for the eastern small-footed bat. We know of only three studies that have attempted to quantify changes in the number of non-hibernating eastern small-footed bats since the spread of WNS (Francl et al. 2012; Nagel and Gates 2012; Moosman et al. in press). At one study location, Surry Mountain Reservoir, New Hampshire, bats were mist-netted over multiple years before and after the emergence of WNS (Moosman et al. in press). Researchers observed a significant decline in the relative abundance of eastern small-footed bats between 2005 and 2011, based on reductions in capture rates. However, they found that the probability of capturing greater than or equal to one eastern small-footed bat on any given visit during the 7 years of study was similar across years, although the probability of capturing other species ( e.g., northern long-eared and little brown bats) declined over time. Moosman et al. (unpublished data) also noted that the observed decline in relative abundance of eastern small-footed bats at their site should not be solely attributed to WNS because of the potential for bats to become trap-shy due to repeated sampling efforts

ar across years, although the probability of capturing other species ( e.g., northern long-eared and little brown bats) declined over time. Moosman et al. (unpublished data) also noted that the observed decline in relative abundance of eastern small-footed bats at their site should not be solely attributed to WNS because of the potential for bats to become trap-shy due to repeated sampling efforts.

Eastern small-footed bats are noted for their ability to detect and avoid mist-nets, perhaps more so than other bat species within their range (Tyburec 2012, unpaginated). In addition, Francl et al. (2012, p. 34) compared bat mist-net data collected from 31 counties in West Virginia prior to the detection of WNS (1997 to 2008) to 8 West Virginia and 1 extreme southwestern Pennsylvania counties surveyed in 2010. Researchers reported a 16-percent decline in the post-WNS capture rate for eastern small-footed bats, although they acknowledge the small sample size may have inherently higher variation and bias compared to more common species that showed consistently negative trends ( e.g., northern long-eared, little brown, and tri-colored bats) (Francl et al. 2012, p. 40). Lastly, during acoustic surveys for bats, Nagel and Gates (2012, p. 5) reported a 63-percent increase in the number of eastern small-footed bat passes during acoustic surveys from 2010 to 2012 in western Maryland, although large declines in bat passes were observed for other species ( e.g., northern long-eared, little brown/Indiana, and tri-colored bats).

Several factors may influen

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