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Modeling anuran detection and site occupancy on North American Amphibian Monitoring Program (NAAMP) routes in Maryland

June 16, 2010

One of the most fundamental problems in monitoring animal populations is that of imperfect detection. Although imperfect detection can be modeled, studies examining patterns in occurrence often ignore detection and thus fail to properly partition variation in detection from that of occurrence. In this study, we used anuran calling survey data collected on North American Amphibian Monitoring Program routes in eastern Maryland to investigate factors that influence detection probability and site occupancy for 10 anuran species. In 2002, 17 calling survey routes in eastern Maryland were surveyed to collect environmental and species data nine or more times. To analyze these data, we developed models incorporating detection probability and site occupancy. The results suggest that, for more than half of the 10 species, detection probabilities vary most with season (i.e., day-of-year), air temperature, time, and moon illumination, whereas site occupancy may vary by the amount of palustrine forested wetland habitat. Our results suggest anuran calling surveys should document air temperature, time of night, moon illumination, observer skill, and habitat change over time, as these factors can be important to model-adjusted estimates of site occupancy. Our study represents the first formal modeling effort aimed at developing an analytic assessment framework for NAAMP calling survey data.

Citation Information

Publication Year 2005
Title Modeling anuran detection and site occupancy on North American Amphibian Monitoring Program (NAAMP) routes in Maryland
DOI 10.1670/0022-1511(2005)039[0627:MADASO]2.0.CO;2
Authors Linda Weir, J. Andrew Royle, Priya Nanjappa, Robin E. Jung
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Herpetology
Series Number
Index ID 5224605
Record Source USGS Publications Warehouse
USGS Organization Patuxent Wildlife Research Center