Estimating demographic parameters using a combination of known-fate and open N-mixture models

Ecology
By: , and 

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Abstract

Accurate estimates of demographic parameters are required to infer appropriate ecological relationships and inform management actions. Known-fate data from marked individuals are commonly used to estimate survival rates, whereas N-mixture models use count data from unmarked individuals to estimate multiple demographic parameters. However, a joint approach combining the strengths of both analytical tools has not been developed. Here we develop an integrated model combining known-fate and open N-mixture models, allowing the estimation of detection probability, recruitment, and the joint estimation of survival. We demonstrate our approach through both simulations and an applied example using four years of known-fate and pack count data for wolves (Canis lupus). Simulation results indicated that the integrated model reliably recovered parameters with no evidence of bias, and survival estimates were more precise under the joint model. Results from the applied example indicated that the marked sample of wolves was biased toward individuals with higher apparent survival rates than the unmarked pack mates, suggesting that joint estimates may be more representative of the overall population. Our integrated model is a practical approach for reducing bias while increasing precision and the amount of information gained from mark–resight data sets. We provide implementations in both the BUGS language and an R package.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Estimating demographic parameters using a combination of known-fate and open N-mixture models
Series title Ecology
DOI 10.1890/15-0385.1
Volume 96
Issue 10
Year Published 2015
Language English
Publisher Ecological Society of America
Contributing office(s) Alaska Science Center Biology WTEB
Description 7 p.
First page 2583
Last page 2589
Country United States
State Alaska
Other Geospatial Gates of the Arctic National Park and Preserve
Online Only (Y/N) N
Additional Online Files (Y/N) N
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