When can the cause of a population decline be determined?

Ecology Letters
By: , and 

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Abstract

Inferring the factors responsible for declines in abundance is a prerequisite to preventing the extinction of wild populations. Many of the policies and programmes intended to prevent extinctions operate on the assumption that the factors driving the decline of a population can be determined. Exogenous factors that cause declines in abundance can be statistically confounded with endogenous factors such as density dependence. To demonstrate the potential for confounding, we used an experiment where replicated populations were driven to extinction by gradually manipulating habitat quality. In many of the replicated populations, habitat quality and density dependence were confounded, which obscured causal inference. Our results show that confounding is likely to occur when the exogenous factors that are driving the decline change gradually over time. Our study has direct implications for wild populations, because many factors that could drive a population to extinction change gradually through time.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title When can the cause of a population decline be determined?
Series title Ecology Letters
DOI 10.1111/ele.12671
Volume 19
Issue 11
Year Published 2016
Language English
Publisher Wiley
Contributing office(s) Coop Res Unit Seattle, National Wildlife Health Center
Description 10 p.
First page 1353
Last page 1362
Online Only (Y/N) N
Additional Online Files (Y/N) N