Occurrence of small mammals in a fragmented landscape: the role of vegetation heterogeneity
Greg J. Holland A B and Andrew F. Bennett AA Landscape Ecology Research Group, School of Life and Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, Vic. 3125, Australia.
B Corresponding author. Email: ghol@deakin.edu.au.
Wildlife Research 34(5) 387-397 https://doi.org/10.1071/WR07061
Submitted: 24 May 2007 Accepted: 2 August 2007 Published: 6 September 2007
Abstract
Most studies of habitat use by small mammals rely on data from trapping grids. Such studies pertain to habitat use by individuals, which may not reflect population-level requirements. To meet the challenge of landscape change, it is important to understand habitat use by populations across large geographic areas. We surveyed small mammals in 48 forest remnants across a 300 km2 study area, to investigate the influence of vegetation heterogeneity on regional distributions. Information-theoretic techniques were used to evaluate models of vegetation associations. Richness of native mammals was influenced by vegetation condition: disturbed sites supported fewer species. Models for individual species showed the agile antechinus, Antechinus agilis, to prefer structurally diverse forest vegetation, the long-nosed potoroo, Potorous tridactylus, to favour mesic shrub communities, the bush rat, Rattus fuscipes, to prefer complex low cover regardless of composition, the swamp rat, Rattus lutreolus, to favour reduced canopy cover, and the house mouse, Mus domesticus, to prefer disturbed vegetation. To satisfy the needs of all native species, a mosaic of natural vegetation is required. Degradation and simplification of forest vegetation have detrimental consequences. These results highlight the need to consider habitat quality, together with more traditional biogeographic variables, when investigating factors influencing patch occupancy by native fauna in modified landscapes.
Acknowledgements
Many thanks go to the various landholders in the Naringal East district of south-western Victoria for allowing access to their properties. We are grateful to all those who gave of their time and assisted with field work. Thanks go to Angie Haslem for digitising the study area and for GIS assistance. Trapping and handling of animals was conducted under Deakin University Animal Ethics Committee approval (A15/2001) and a Department of Sustainability and Environment Research Permit (10001802). Financial support was provided by the Holsworth Wildlife Research Endowment, Deakin University, and an Australian Postgraduate Award received by G. Holland. Thanks go to two anonymous reviewers for comments on an earlier draft of the manuscript.
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