Report

Resource Management Cycles and the Sustainability of Harvested Wildlife Populations

+ See all authors and affiliations

Science  14 May 2010:
Vol. 328, Issue 5980, pp. 903-906
DOI: 10.1126/science.1185802

You are currently viewing the abstract.

View Full Text

Population Meltdown

Populations of wild animals, including deer and moose, are often actively managed by hunting. Following such harvesting, populations of some exploited animal species collapse, whereas others are able to withstand exploitation. To understand the reasons for these varied responses, Fryxell et al. (p. 903) developed a mathematical model which predicts that weak regulation causes damped population cycles with period lengths on the order of decades. The model was tested using time-series data for hunted populations of moose and deer in three ecosystems in Norway and Canada.

Abstract

Constant harvest policies for fish and wildlife populations can lead to population collapse in the face of stochastic variation in population growth rates. Here, we show that weak compensatory response by resource users or managers to changing levels of resource abundance can readily induce harvest cycles that accentuate the risk of catastrophic population collapse. Dynamic system models incorporating this mix of feedback predict that cycles or quasi-cycles with decadal periodicity should commonly occur in harvested wildlife populations, with effort and quotas lagging far behind resources, whereas harvests should exhibit lags of intermediate length. Empirical data gathered from three hunted populations of white-tailed deer and moose were consistent with these predictions of both underlying behavioral causes and dynamical consequences.

View Full Text