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Publication Date

February 2009


Emory Cave (Texas, United States), United States




Authors: Loren K. Ammerman 1,*, Molly McDonough 1, 3, Nickolay I. Hristov 2, 4, Thomas H. Kunz 2 1Department of Biology, ASU Station Box 10890, Angelo State University, San Angelo, Texas 76909, USA 2Center for Ecology and Conservation Biology, Department of Biology, 5 Cummington Street, Boston University, Boston, Massachusetts 02215, USA 3 Present address: Department of Biological Science, Box 43131, Texas Tech University, Lubbock, Texas 79409, USA 4 Present address: Department of Ecology and Evolutionary Biology, 80 Waterman Street, Brown University, Providence, Rhode Island 02912, USA ABSTRACT: Emory Cave in west Texas, USA is one of the few natural roost sites used by the endan- gered Mexican long-nosed bat Leptonycteris nivalis in the United States. Despite concern over declines in population size, no reliable methods have been developed for censusing colonies of this species that are both accurate and minimize disruption to the colony. The objective of this study was to use non-invasive thermal infrared imaging to census L. nivalis as individuals emerge from Emory Cave and to evaluate the success of this method for future monitoring efforts. We recorded 6 emer- gences of bats from Emory Cave (4 and 5 June, 4 and 5 July, 4 and 5 August 2005) using thermal infrared cameras. Recordings were manually reviewed, and peak emergence rate was determined to be 54, 159, and 61 bats min-1 in June, July and August, respectively. The greatest number of L. nivalis (at least 2742 to 2874) was present in July. Overall, our data suggest that thermal infrared imaging provides a more reliable and accurate estimate of the number of L. nivalis at Emory Cave than has previously been possible using extrapolation from surface area of the cave ceiling covered by bats. KEY WORDS: Thermal infrared imaging · Census · Leptonycteris nivalis · Emergence · Big Bend National Park · Emory Cave · Mexican long-nosed bat Open Access See Extended description for more information.





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