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Separating the influences of environment and species interactions on patterns of distribution and abundance: competition between large herbivores
Citation
Ritchie, EG and Martin, JK and Johnson, CN and Fox, BJ, Separating the influences of environment and species interactions on patterns of distribution and abundance: competition between large herbivores , Journal of Animal Ecology, 78, (4) pp. 724-731. ISSN 0021-8790 (2009) [Refereed Article]
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Copyright Statement
The definitive published version is available online at: http://www.interscience.wiley.com
DOI: doi:10.1111/j.1365-2656.2008.01520.x
Abstract
1.
Much recent research has focused on the use of species distribution models to explore the influence(s)
of environment (predominantly climate) on species’ distributions. A weakness of this approach is
that it typically does not consider effects of biotic interactions, including competition, on species’
distributions.
2.
Here we identify and quantify the contribution of environmental factors relative to biotic factors
(interspecific competition) to the distribution and abundance of three large, wide-ranging
herbivores, the antilopine wallaroo (
Macropus antilopinus
), common wallaroo (
Macropus robustus
)
and eastern grey kangaroo (
Macropus giganteus
), across an extensive zone of sympatry in tropical
northern Australia.
3.
To assess the importance of competition relative to habitat features, we constructed models of
abundance for each species incorporating habitat only and habitat + the abundance of the other
species, and compared their respective likelihoods using Akaike’s information criterion. We further
assessed the importance of variables predicting abundance across models for each species.
4.
The best-supported models of antilopine wallaroo and eastern grey kangaroo abundance
included both habitat and the abundance of the other species, providing evidence of interspecific
competition. Contrastingly, models of common wallaroo abundance were largely influenced by
climate and not the abundance of other species. The abundance of antilopine wallaroos was most
influenced by water availability, eastern grey kangaroo abundance and the frequency of late season
fires. The abundance of eastern grey kangaroos was most influenced by aspects of climate, antilopine
wallaroo abundance and a measure of cattle abundance.
5.
Our study demonstrates that where census and habitat data are available, it is possible to reveal
species’ interactions (and measure their relative strength and direction) between large, mobile and/
or widely-distributed species for which competition is difficult to demonstrate experimentally. This
allows discrimination of the influences of environmental factors and species interactions on species’
distributions, and should therefore improve the predictive power of species distribution models.
Item Details
Item Type: | Refereed Article |
---|---|
Research Division: | Biological Sciences |
Research Group: | Ecology |
Research Field: | Community ecology (excl. invasive species ecology) |
Objective Division: | Environmental Management |
Objective Group: | Terrestrial systems and management |
Objective Field: | Terrestrial biodiversity |
UTAS Author: | Johnson, CN (Professor Christopher Johnson) |
ID Code: | 72240 |
Year Published: | 2009 |
Web of Science® Times Cited: | 47 |
Deposited By: | Zoology |
Deposited On: | 2011-08-24 |
Last Modified: | 2012-03-06 |
Downloads: | 0 |
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