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A hierarchical analysis of population change with application to Cerulean Warblers

Ecology

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Abstract

Estimation of population change from count surveys is complicated by variation in quality of information among sample units, by the need for covariates to accommodate factors that influence detectability of animals, and by multiple geographic scales of interest. We present a hierarchical model for estimation of population change from the North American Breeding Bird Survey. Hierarchical models, in which population parameters at different geographic scales are viewed as random variables, provide a convenient framework for summary of population change among regions, accommodating regional variation in survey quality and a variety of distributional assumptions about observer effects and other nuisance parameters. Markov chain Monte Carlo methods provide a convenient means for fitting these models and also allow for construction of estimates of derived variables such as weighted regional trends and composite yearly population indices. We construct an overdispersed Poisson regression model for estimation of trend and year effects for Cerulean Warblers (Dendroica cerulea), accommodating nuisance covariates for observer and start-up effects, and estimating abundance- and area-weighted annual indices at regional and continent-wide geographic scales. A goodness-of-fit test is also presented for the model. Cerulean Warblers declined at a rate of 3.04% per year over the interval 1966-2000.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A hierarchical analysis of population change with application to Cerulean Warblers
Series title:
Ecology
Volume
83
Issue:
10
Year Published:
2002
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
2832-2840
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Ecology
First page:
2832
Last page:
2840