Biostatistics Research Today is a free monthly online journal that collates and summarizes the latest research about Biostatistics, including details on statistics, uncertainty, probability, modeling.

Accommodating unmodeled heterogeneity in double-observer distance sampling surveys.

Borchers DL, Laake JL, Southwell C, Paxton CG

Research Unit for Wildlife Population Assessment, The Observatory, Buchanan Gardens, University of St. Andrews, Fife, KY16 9LZ, Scotland. dlb@mc.st-and.ac.uk

Mark-recapture models applied to double-observer distance sampling data neglect the information on relative detectability of objects contained in the distribution of observed distances. A difference between the observed distribution and that predicted by the mark-recapture model is symptomatic of a failure of the assumption of zero correlation between detection probabilities implicit in the mark-recapture model. We develop a mark-recapture-based model that uses the observed distribution to relax this assumption to zero correlation at only one distance. We demonstrate its usefulness in coping with unmodeled heterogeneity using data from an aerial survey of crabeater seals in the Antarctic.

Published 21 August 2006 in Biometrics, 62(2): 372-8.
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