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USGS · 70025211

Tag loss can bias Jolly-Seber capture-recapture estimates

T. L. McDonald·Steven C. Amstrup·B.F.J. Manly
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Abstract

We identified cases where the Jolly-Seber estimator of population size is biased under tag loss and tag-induced mortality by examining the mathematical arguments and performing computer simulations. We found that, except under certain tag-loss models and high sample sizes, the population size estimators (uncorrected for tag loss) are severely biased high when tag loss or tag-induced mortality occurs. Our findings verify that this misconception about effects of tag loss and tag-induced mortality could have serious consequences for field biologists interested in population size. Reiterating common sense, we encourage those engaged in capture-recapture studies to be careful and humane when handling animals during tagging, to use tags with high retention rates, to double-tag animals when possible, and to strive for the highest capture probabilities possible.

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T. L. McDonald, Steven C. Amstrup, B.F.J. Manly. 2003. Tag loss can bias Jolly-Seber capture-recapture estimates. https://pubs.usgs.gov/publication/70025211

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