Do harvest refuges buffer kangaroos against evolutionary responses to selective harvesting?

Authored by B Tenhumberg, HP Possingham, AJ Tyre, AR Pople

Date Published: 2004

DOI: 10.1890/03-4111

Sponsors: Murray-Darling Basin Authority

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

There is a wealth of literature documenting a directional change of body size in heavily harvested populations. Most of this work concentrates on aquatic systems, but terrestrial populations are equally at risk. This paper explores the capacity of harvest refuges to counteract potential effects of size-selective harvesting on the allele frequency,of populations. We constructed a stochastic, individual-based model parameterized with data on red kangaroos. Because we do not know which part of individual growth would change in the course of natural selection, we explored the effects of two alternative models of individual growth in which alleles affect either the growth rate or the maximum size. The model results show that size-selective harvesting can result in significantly smaller kangaroos for a given age when the entire population is subject to harvesting. In contrast, in scenarios that include dispersal from harvest refuges, the initial allele frequency remains virtually unchanged.

Tags

Habitat fragmentation Population-dynamics Natural-selection Reproduction New-south-wales Life-history evolution Reef fishes Western grey kangaroos Sympatric red kangaroos Macropus-rufus