Bat Surveys on USFS Northern Region Lands in Montana: 2007 Prepared for: USDA Forest Service, Northern Region P.O. Box 7669 Missoula, MT 59807 Prepared by: Susan Lenard, Paul Hendricks and Bryce A. Maxell Montana Natural Heritage Program a cooperative program of the Montana State Library and the University of Montana January 2009 Bat Surveys on USFS Northern Region Lands in Montana: 2007 Prepared for: USDA Forest Service, Northern Region P. O. Box 7669 Missoula, MT 59807 Agreement Number: 06-CS-11015600-031 Prepared by: Susan Lenard, Paul Hendricks and Bryce A. Maxell © 2009 Montana Natural Heritage Program P.O. Box 201800 • 1515 East Sixth Avenue • Helena, MT 59620-1800 • 406-444-5354 i This document should be cited as follows: Lenard, S., P. Hendricks, and B. A. Maxell. 2009. Bat Surveys on USFS Northern Region Lands in Montana: 2007. A report to the USDA Forest Service, Northern Region. Montana Natural Heritage Program, Helena, MT. 21 pp. plus appendices. ii E S XECUTIVE UMMARY The U.S. Forest Service Northern Region has respective species to be detected by any method conducted bat surveys each year during 2005-2007 during the fi rst three years of the USFS Northern to gather information on the distribution and status Region inventory. Call analysis on the 2007 of bats on Forest Service lands in Montana. During acoustic surveys has not been completed at the 2005, 57 sites were surveyed on selected National time this report was prepared. Genetic analysis is Forest (NF) Ranger Districts (RD); the 2005 fi eld needed to confi rm tentative identifi cations of some season provided information for areas previously Myotis taxa at several netting sites. No bats were without documented bat activity and resulted in detected at ten sites and are not included in the total numerous new county records for several species. number of site surveys for 2007. In 2006, with an increased number of surveyors, 75 new sites were surveyed using both mist-net The 2007 surveys fi lled important gaps in and acoustic sampling methods. A pilot project documented bat distributions in Montana, as was undertaken following the 2006 fi eld season to well as on Ranger Districts formerly lacking any investigate bat detection probabilities for surveys surveys. However, a summary of all existing using more than one detection method (mist- Northern Region bat records continues to show netting and acoustic sampling). During the 2007 large distribution gaps for all species, underscoring fi eld season, 87 new sites were surveyed: 59 the need for additional surveys. In particular, acoustically, 28 mist-netted. Areas targeted for large portions of the Bitterroot, Flathead, Gallatin, survey included RDs and/or backcountry areas of Kootenai, and Lewis and Clark National Forests select RDs lacking any survey coverage. These lack records for any bat species or any recently included the Dillon, Jefferson, Madison, Pintler, documented activity. Up-to-date distribution maps Wisdom, and Wise River RDs of the Beaverhead- for Montana’s species can be queried and viewed Deerlodge NF; the Ashland and Beartooth RDs with a variety of map layers on the Montana of the Custer NF; Glacier View, Hungry Horse, Natural Heritage Program’s TRACKER website at: Spotted Bear, Swan Lake, and Tally Lake RDs of http://mtnhp.org/Tracker. the Flathead NF; the Gardiner RD of the Gallatin NF; the Rocky Mountain RD of the Lewis and Morphometric data collected in Montana, Clark NF; and the Seeley Lake and Superior RDs Idaho, and South Dakota during 2005-2007 of the Lolo NF. were comparable with previously documented measurements in the region, although a few records Ten species of bats, represented by 218 individuals, were outside the limits of published ranges. For were captured by mist-net during mid June-late the eight species where a signifi cant difference August 2007. Species captured included Little was detected, females exceeded males in mean Brown Myotis (Myotis lucifugus), Western forearm length in all but Western Long-eared Long-eared Myotis (M. evotis), Long-legged Myotis. Mean weight and ear length were not Myotis (M. volans), California Myotis (M. clearly differentiated by sex. Data collected from californicus), Big Brown Bat (Eptesicus fuscus), captured bats during the USFS Northern Region Hoary Bat (Lasiurus cinereus), Silver-haired Bat surveys can help identify regional differences in (Lasionycteris noctivagans), Townsend’s Big-eared bat morphometrics, supplement regional natural Bat (Corynorhinus townsendii), Eastern Red Bat history information, and assist in refi ning in-hand (Lasiurus borealis), and Pallid Bat (Antrozous identifi cation techniques. pallidus); the latter two are the fi rst of their iii A CKNOWLEDGEMENTS We thank Fred Samson, Jenny Taylor, Beth Hahn, Lewis and Clark NF by Paul Hendricks; and on the and Skip Kowalski (USFS) for initiating and Lolo NF by Paul Hendricks, Cori Lausen, Jenny promoting the project through the USFS Regional Taylor, Amie Shovlain, Sarah Kaufman, Amanda Inventory and Monitoring (RIM) program, and Playter, Sam Skalak, and Zeeke Steele. overseeing its implementation. Scott Blum (MTNHP) entered survey data into On-the-ground 2007 surveys were conducted on the Montana Natural Heritage Program’s Point the Beaverhead-Deerlodge NF by Barbara Garcia, Observation Database, facilitating the production of Amie Shovlain, Sam Skalak, Amanda Playter, new distribution maps and the updating of element Robert Garcia, and Dave Ritts; on the Custer NF occurrence data in the Montana Natural Heritage by Lewis Young, Don Sasse, Amanda Playter, Program’s database. Coburn Currier (MTNHP) Jenny Holifi eld and Susan Lenard; on the Gallatin edited, formatted, and printed this report. We thank NF by Jennifer Holifi eld and Susan Lenard; on the all of those involved, from the beginning of the Flathead by Cori Lausen, Erin Baerwald, Brandon project to the printing of this report. Klug, Jennifer Holifi eld and Lewis Young; on the v T C ABLE OF ONTENTS Introduction .....................................................................................................................................1 Methods...........................................................................................................................................3 Focus of 2007 Efforts ................................................................................................................3 Field Methods ...........................................................................................................................3 Results .............................................................................................................................................5 Overview 2007 ..........................................................................................................................5 Species Captured During Mist Netting Surveys .......................................................................5 Sex and Age Ratios ...................................................................................................................7 Evidence of Reproduction by Females .....................................................................................7 Survey Coverage with Sampling Grid ......................................................................................7 Overview of the 2005-2007 USFS Northern Region Bat Surveys .........................................10 Species Captured ...............................................................................................................10 Sex Ratios .........................................................................................................................11 Age Class Ratios ...............................................................................................................12 Reproductive Status Ratios ...............................................................................................12 Morphometric Comparison ...............................................................................................13 Discussion .....................................................................................................................................17 Recommendations .........................................................................................................................18 Literature Cited .............................................................................................................................19 Appendix A: Global / State Rank Defi nitions Appendix B: Distribution Map for Bats in Montana Appendix C: USFS Northern Region Montana Bat Survey Sites 2007 Appendix D: Records Deleted from USFS 2005-2007 Morphometric Summary Appendix E: Documented Species List per Forest/District in Montana L F IST OF IGURES Figure 1. Map of bat observations in Montana .........................................................................4 Figure 2. Protocol cells covered ...............................................................................................8 Figure 3. Districts without survey effort in 2005-2007 ............................................................9 L T IST OF ABLES Table 1. Number of survey sites per District in 2007 ................................................................5 Table 2. Bat species captured during Surveys in 2007 ..............................................................6 Table 3. Number of sites where bats were netted and total number of individuals captured on four Region 1 National Forests in Montana, 12 June-29 August 2007 ..................6 Table 4. Sex and age ratios for bat species captured in Montana in 2007 .................................7 Table 5. Total number of cells per Forest with multiple surveys (Fit Protocol) for 2007 and combined 2005 - 2007 as percentage of overall total cells ........................10 vi L T ( ’ ) IST OF ABLES CON T Table 6. Comparison of all Montana bat data (MTHNP Point Observation Database) and data collected in multiple survey cells in 2007 with overall predicted number of species ......................................................................................................10 Table 7. Individuals captured per year by sex .........................................................................11 Table 8. Sex ratio by age class for all species captured 2005-2007 ........................................11 Table 9. Reproductive status across all species 2005-2007 .....................................................12 Table 10. Forearm length (mm) for adult bats of all species 2005-2007 ..................................14 Table 11. Weight (g) for bats of all species 2005-2007 .............................................................15 Table 12. Ear length (mm) for bats of all species 2005-2007 ...................................................16 vii I NTRODUCTION Recognition of a general lack of basic natural zone bats (Humphrey 1975, Dobkin et al. 1995), history information on native bat species, especially cave- and crevice-dwelling taxa. widespread disturbance, alteration, and/or complete removal of habitats traditionally used by bats Most bat species use a variety of localized habitats for roosting and foraging have contributed to for roosting, whether they are natural sites (e.g., increasing concern in recent decades about the caves, trees, rock crevices) or man-made sites (e.g., status of bats throughout North America (Fenton buildings, mines, bridges). Sites may be used only 1997, Pierson 1998, Hayes 2003). As a result, six for specifi c purposes during specifi c seasons of species or subspecies of bats in the continental the year. Recent fi eld studies of bats in Montana United States are currently classifi ed as endangered have followed the national pattern of inventorying under the United States Endangered Species and monitoring roosts in caves, abandoned mines, Act of 1973 (O’Shea et al. 2003). While none and bridges (e.g., Worthington 1991a, 1991b, of these federally listed bats occur in Montana, Hendricks et al. 2000, 2004, 2005; Hendricks seven other species are recognized by the state as and Kampwerth 2001); survey and monitoring Species of Concern: Eastern Red Bat - Lasiurus of roosts remains an important activity for a state borealis (G5 S2S3); Hoary Bat - Lasiurus cinereus bat conservation plan. Nevertheless, sampling (G5 S3); Fringed Myotis - Myotis thysanodes bats across the landscape at foraging sites also is (G4G5 S3); Northern Long-eared Myotis - Myotis critical for fi lling gaps in documented distributions septentrionalis (G4 S2S3); Pallid Bat - Antrozous and assessing the relative abundance of local pallidus (G5 S2); Spotted Bat - Euderma populations, and can contribute to the discovery of maculatum (G4 S2); Townsend’s Big-eared Bat - new roosts. Corynorhinus townsendii (G4 S2) (See Appendix A for Rank Defi nitions) (MTNHP and MFWP 2008). Inventory efforts over the past three years have The U.S. Forest Service Northern Region lists improved understanding of the distribution and Townsend’s Big-eared Bat, Pallid Bat and Spotted status of bats on U.S. Forest Service Northern Bat as Species of Concern. Region lands in Montana. The USFS Northern Region inventory has generally followed the While conservation and protection of roosts are Oregon Bat Grid Protocols, by sampling the important long-term management considerations presence of bat species using a standardized effort for many North American bat species (Sheffi eld et and sample unit across the state. The protocol al. 1992), efforts to conserve bats in Montana are includes collecting baseline data on acoustic, often hampered by a lack of data on general habitat morphologic, and genetic characteristics for bat requirements. For example, the little data available species occupying the Northern Region. While from Montana on foraging behavior and diet of important information has already been gathered bats have largely been obtained at water sources on Montana’s bats, more work needs to be done; (Jones et al. 1973), with no knowledge of where substantial distribution holes remain and little the foraging bats are roosting (Thomas 1988). progress has been made in identifying important Conversely, studies of bat roosts in Montana (e.g., roosting locations. Worthington 1991a, 1991b, Hendricks et al. 2000, 2004) lack information on where and how far roost A summary of all existing bat records across the members go to feed and drink. In addition, patterns region clearly shows large distribution gaps for of roost selection and fi delity (e.g., Sherwin et all species, further underscoring the need for al. 2003) have not been studied in Montana, even additional surveys (Appendix B). In particular, though it is understood that suitable summer and large portions of the Bitterroot NF, Custer NF, winter roosts may limit the local and regional Flathead NF, Gallatin NF, Kootenai NF, and Lewis distribution and abundance of many temperate- and Clark NF lack records or standard surveys for any bat species. 1 Management activities may have unintended populations reside, for example mountain versus consequences for bat populations and the habitats prairie environments (Solick and Barclay 2006). they use for roosting and foraging as a result of The confusion can be confounded further when insuffi cient data on which species are present on sympatric species are nearly indistinguishable in the landscape, and where they concentrate their the hand, the case for the Little Brown Myotis activities. The Northern Region recognized the (Myotis lucifugus) and Yuma Myotis (Myotis need for additional documentation of bats on Forest yumanensis) (Weller et al. 2007, Rodhouse et al. Service lands to address inventory and monitoring 2008). requirements, and initiated bat surveys across the Region on selected National Forest Ranger Variable external morphology is not the only Districts in 2005. Given that large areas of the problem, however. Some species, such as Silver- Region still lack bat data, the primary goal of the haired Bat (Lasionycteris noctivagans) and 2007 fi eld season was to document bat species Big Brown Bat (Eptesicus fuscus), are readily richness (number of species) within sample units identifi ed in-hand but their individual ultrasonic for areas with limited or no bat data. These surveys calls often have overlapping frequency and shape were conducted generally following the 2005 characteristics (Betts 1998). Thus, it is often protocols. desirable to gather morphometric, ultrasonic, and genetic (tissue) data from individuals to maximize Effective inventory requires accurate identifi cation likelihood of detection and positive identifi cation, of the target species, in this case a suite of bats. as well as to determine where and when One objective of the USFS Northern Region bat identifi cation may be problematic; gathering the inventory is the collection of morphometric and necessary information often requires using more ultrasonic data to improve species identifi cations, than one sampling method (trapping and ultrasonic as well as to determine if signifi cant differences call capture analysis). in these traits occur within the region. Many bat species present confusing attributes to fi eld In this report we present 1) inventory results of workers, even personnel with fi eld experience, the 2007 fi eld season, 2) a summary of grid cell confounding correct identifi cation of captured coverage for the effort to date (2005-2007), and animals. Morphological traits often used in 3) an analysis of all standard morphometric traits dichotomous keys to identify bats (e.g., forearm taken from bats captured during 2005-2007, with length) can vary substantially between sexes of discussion of their utility for making species single species (Hendricks et al. 2000, Solick and determinations. Analyses of tissue samples and Barclay 2006), and across large geographical data call are still pending. ranges or among habitats in which different 2