Estimating Site Occupancy Rates When Detection Probabilities Are Less Than One
2002; Wiley; Volume: 83; Issue: 8 Linguagem: Inglês
10.2307/3072056
ISSN1939-9170
AutoresDarryl I. MacKenzie, James D. Nichols, Gideon B. Lachman, Sam Droege, J. Andrew Royle, Catherine A. Langtimm,
Tópico(s)Amphibian and Reptile Biology
ResumoNondetection of a species at a site does not imply that the species is absent unless the probability of detection is 1. We propose a model and likelihood-based method for estimating site occupancy rates when detection probabilities are 0.3). We estimated site occupancy rates for two anuran species at 32 wetland sites in Maryland, USA, from data collected during 2000 as part of an amphibian monitoring program, Frogwatch USA. Site occupancy rates were estimated as 0.49 for American toads (Bufo americanus), a 44% increase over the proportion of sites at which they were actually observed, and as 0.85 for spring peepers (Pseudacris crucifer), slightly above the observed proportion of 0.83.
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