Are smaller subspecies of common brushtail possums more omnivorous than larger ones?
Article first published online: 17 FEB 2012
© 2012 The Authors. Austral Ecology © 2012 Ecological Society of Australia
Volume 37, Issue 8, pages 893–902, December 2012
How to Cite
CRUZ, J., SUTHERLAND, D. R., MARTIN, G. R. and LEUNG, L. K.-P. (2012), Are smaller subspecies of common brushtail possums more omnivorous than larger ones?. Austral Ecology, 37: 893–902. doi: 10.1111/j.1442-9993.2011.02346.x
- Issue published online: 21 NOV 2012
- Article first published online: 17 FEB 2012
- Accepted for publication December 2011.
- brushtail possum;
- feeding habit;
- Trichosurus vulpecula
Body size is often associated with a dietary divergence within taxonomically related groups so that large animals are often folivorous, while smaller species shift progressively towards omnivory or carnivory. This trend may be influenced by allometric constrains which result in relatively high energetic requirements, but low gut capacities in small animals, compared to their large counterparts. The common brushtail possum (Trichosurus vulpecula, Phalangeridae) has six subspecies ranging widely in weight (1–4 kg). They are not strictly folivorous, but supplement their diet with more nutritious, non-foliar foods. We predicted that T. vulpecula subspecies diverged in diet in association with body size, with smaller subspecies consuming higher proportions of non-foliar foods. We assessed this with a review and a meta-analysis of previous Australian studies. We also investigated the previously unquantified diet of T. v. hypoleucus at three sites in the northern jarrah forest of Western Australia. Results from the meta-analysis and the review supported our prediction. However, the large variability in the data highlighted their limitations and those of the techniques commonly used to quantify the diet of T. vulpecula. Nonetheless, small subspecies of T. vulpecula appear to consume higher proportions of non-foliar foods. These results should encourage further research into the body size/diet relationship within T. vulpecula and other possum species. Results from the dietary study of T. v. hypoleucus emphasized their omnivorous diet, which was dominated by foliage and flowers and smaller proportions of invertebrates, seeds and fruits. The common brushtail possum is seldom an exclusive arboreal folivore, but rather ranges from folivory to omnivory.