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Site‐selection bias and apparent population declines in long‐term studies
Author(s) -
Fournier Auriel M.V.,
White Easton R.,
Heard Stephen B.
Publication year - 2019
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1111/cobi.13371
Subject(s) - term (time) , selection (genetic algorithm) , population , geography , biology , computer science , medicine , physics , environmental health , artificial intelligence , quantum mechanics
Detecting population declines is a critical task for conservation biology. Logistical difficulties and the spatiotemporal variability of populations make estimation of population declines difficult. For statistical reasons, estimates of population decline may be biased when study sites are chosen based on abundance of the focal species. In this situation, apparent population declines are likely to be detected even if there is no decline. This site‐selection bias is mentioned in the literature but is not well known. We used simulations and real population data to examine the effects of site‐selection biases on inferences about population trends. We used a left‐censoring method to detect population‐size patterns consistent with site‐selection bias. The site‐selection bias is an important consideration for conservation biologists, and we offer suggestions for minimizing or mitigating it in study design and analysis. Article impact statement : Estimates of population declines are biased if studies begin in large populations, and time‐series data show a signature of such an effect.