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A robust design mark-resight abundance estimator allowing heterogeneity in resighting probabilities

Journal of Agricultural, Biological, and Environmental Statistics

By:
, , and
DOI: 10.1198/108571106X129171

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Abstract

This article introduces the beta-binomial estimator (BBE), a closed-population abundance mark-resight model combining the favorable qualities of maximum likelihood theory and the allowance of individual heterogeneity in sighting probability (p). The model may be parameterized for a robust sampling design consisting of multiple primary sampling occasions where closure need not be met between primary occasions. We applied the model to brown bear data from three study areas in Alaska and compared its performance to the joint hypergeometric estimator (JHE) and Bowden's estimator (BOWE). BBE estimates suggest heterogeneity levels were non-negligible and discourage the use of JHE for these data. Compared to JHE and BOWE, confidence intervals were considerably shorter for the AICc model-averaged BBE. To evaluate the properties of BBE relative to JHE and BOWE when sample sizes are small, simulations were performed with data from three primary occasions generated under both individual heterogeneity and temporal variation in p. All models remained consistent regardless of levels of variation in p. In terms of precision, the AICc model-averaged BBE showed advantages over JHE and BOWE when heterogeneity was present and mean sighting probabilities were similar between primary occasions. Based on the conditions examined, BBE is a reliable alternative to JHE or BOWE and provides a framework for further advances in mark-resight abundance estimation. ?? 2006 American Statistical Association and the International Biometric Society.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A robust design mark-resight abundance estimator allowing heterogeneity in resighting probabilities
Series title:
Journal of Agricultural, Biological, and Environmental Statistics
DOI:
10.1198/108571106X129171
Volume
11
Issue:
3
Year Published:
2006
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Agricultural, Biological, and Environmental Statistics
First page:
231
Last page:
248
Number of Pages:
18