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Digital Photography Improves Consistency and Accuracy of Bat Counts in Hibernacula
Author(s) -
MERETSKY VICKY J.,
BRACK VIRGIL,
CARTER TIMOTHY C.,
CLAWSON RICHARD,
CURRIE ROBERT R.,
HEMBERGER TRACI A.,
HERZOG CARL J.,
HICKS ALAN C.,
KATH JOSEPH A.,
MACGREGOR JOHN R.,
KING R. ANDREW,
GOOD DAVID H.
Publication year - 2010
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.2193/2008-306
Subject(s) - digitization , photography , endangered species , listing (finance) , estimation , consistency (knowledge bases) , population , digital photography , geography , ecology , computer science , biology , computer vision , artificial intelligence , visual arts , habitat , demography , management , finance , economics , art , sociology
The size and distribution of measurement errors associated with major techniques for estimating numbers of hibernating bats are unstudied, although this is the principle method of enumerating several endangered bat species. However, decisions concerning the listing status of a species under the Endangered Species Act require consistent and accurate estimation of population size and trends. Recent advances in digital photography have improved the ability to produce a quantitative record of the numbers of bats in hibernacula. We surveyed clusters of Indiana bats in a hibernaculum and compared results from counts of digital photographs of clusters to results from 4 variations of visual estimation. We counted bats in photographs using Geographic Information System digitization over the photograph. Total counts from 2 sets of photographs varied by <1.5%. Nonphotographic estimation techniques varied from 76% to 142% of counts from photographs for clusters for which estimation (rather than counting) was used. Where feasible, photography can improve status and trend information for species of concern, permitting more timely and specific management actions.