Long-term monitoring of endangered Mexican Long-nosed Bats (Leptonycteris nivalis) and a test of an automated census approach
Loren K. Ammerman1,*, Ashley E. Loehn1, Flor A. Calderon1, Roxanne D. Pourshoushtari1,2, Erin R. Adams1,3, and Michael T. Dixon1
1Department of Biology, Angelo State University, San Angelo, TX 76909. 2Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30605. 3Washington Fish and Wildlife Office, U.S. Fish and Wildlife Service, Lacey, WA 98503.*Corresponding author.
Journal of North American Bat Research, Special Issue 1 (2024): 11–29
Abstract
Management strategies for bats require accurate knowledge of population size to determine population trends. We used thermal-infrared cameras to record bats, including endangered Mexican Long-nosed Bats (Leptonycteris nivalis), emerging from a roost between 2008 and 2023. Thirty-five videos were analyzed manually to obtain a count of emerging bats and then were analyzed using an automated program, ThruTracker. This automated method generally performed well, with overall 90.8% accuracy (range = 64–99%). Maximum annual colony size of L. nivalis fluctuated from 294 to 3360 bats (mean = 2156) across 16 years. There was no evidence of a significant decline. We conclude that ThruTracker software can be effective for estimating overall population size and for detecting changes in populations over time.
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Journal of North American Bat Research is valued by the academic, agency, NGO, and private-sector research community as a respected and trusted source for science related to all aspects of the biology, ecology, and conservation of bats, Order Chiroptera, and their habitats in North America, from Canada to Panama, and the West Indies (Bahamas, Greater Antilles, and Lesser Antilles). Manuscripts based on studies outside this region that provide information on species within the region may be considered at the Editor’s discretion.