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Experimental Investigation of Observation Error in Anuran Call Surveys
Author(s) -
Mcclintock Brett T.,
Bailey Larissa L.,
Pollock Kenneth H.,
Simons Theodore R.
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 - 10.2193/2009-321
Subject(s) - occupancy , songbird , false positive paradox , ambient noise level , estimator , computer science , false positives and false negatives , observer (physics) , limiting , noise (video) , statistics , false positive rate , ecology , mathematics , artificial intelligence , biology , acoustics , mechanical engineering , physics , quantum mechanics , engineering , image (mathematics) , sound (geography)
Occupancy models that account for imperfect detection are often used to monitor anuran and songbird species occurrence. However, presence—absence data arising from auditory detections may be more prone to observation error (e.g., false‐positive detections) than are sampling approaches utilizing physical captures or sightings of individuals. We conducted realistic, replicated field experiments using a remote broadcasting system to simulate simple anuran call surveys and to investigate potential factors affecting observation error in these studies. Distance, time, ambient noise, and observer abilities were the most important factors explaining false‐negative detections. Distance and observer ability were the best overall predictors of false‐positive errors, but ambient noise and competing species also affected error rates for some species. False‐positive errors made up 5% of all positive detections, with individual observers exhibiting false‐positive rates between 0.5% and 14%. Previous research suggests false‐positive errors of these magnitudes would induce substantial positive biases in standard estimators of species occurrence, and we recommend practices to mitigate for false positives when developing occupancy monitoring protocols that rely on auditory detections. These recommendations include additional observer training, limiting the number of target species, and establishing distance and ambient noise thresholds during surveys.