The effect of density-dependent catastrophes on population persistence time

Wilcox, Chris and Elderd, Bret (2003) The effect of density-dependent catastrophes on population persistence time. Journal of Applied Ecology, 40 5: 859-871. doi:10.1046/j.1365-2664.2003.00852.x

Author Wilcox, Chris
Elderd, Bret
Title The effect of density-dependent catastrophes on population persistence time
Journal name Journal of Applied Ecology   Check publisher's open access policy
ISSN 0021-8901: 1365-2654: 1365-2664
Publication date 2003-10
Sub-type Article (original research)
DOI 10.1046/j.1365-2664.2003.00852.x
Volume 40
Issue 5
Start page 859
End page 871
Total pages 13
Place of publication Oxford, United Kingdom
Publisher Blackwell Publishing Ltd
Collection year 2003
Language eng
Subject C1
270700 Ecology and Evolution
779903 Living resources (flora and fauna)
Formatted abstract
There has been increasing recognition that catastrophes are an important factor in modelling threatened populations. However, density dependence has generally been omitted from models of threatened populations on the assumption that this omission yields conservative predictions. We explore the significance of including density-dependent catastrophes in models of threatened populations.

Using an analytical model, we show that density-dependent catastrophes have a significant effect on population persistence, decreasing mean persistence time at large population sizes and causing a relative increase at intermediate sizes.


We illustrate our results with empirical data from a disease outbreak in crabeater seals Lobodon carcinophagus and show that intermediate population sizes have the longest predicted persistence times.

The pattern we found is qualitatively different from previous results on persistence time based on density-independent models, in which persistence time increases with population size to an asymptote.

Synthesis and applications. This study has important implications for the conservation of species that may experience density-dependent catastrophes, such as disease outbreaks or starvation. Our results indicate that small and intermediate sized populations may contribute disproportionately to species persistence. Thus populations that have been dismissed as 'marginal' may actually be important for conservation. In addition, culling may increase the persistence of populations that experience density-dependent catastrophes.
Keyword Ecology
Birth-death Markov Process
Viability Analysis
Serengeti Wildebeest
Large Mammals
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2004 Higher Education Research Data Collection
School of Biological Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 16 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 16 times in Scopus Article | Citations
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Created: Tue, 14 Aug 2007, 19:15:33 EST