Four species of arboreal folivore show differential tolerance to a secondary metabolite
Lora M. Jensen1,2 · Ian R. Wallis1 · Karen J. Marsh1 · Ben D. Moore3 · Natasha L. Wiggins4 · William J. Foley1
1Evolution, Ecology and genetics, research school of Biology, australian national University, canberra, act 0200, australia
2Biomedical sciences, Faculty of applied science, University of canberra, canberra, act 2617, australia
3hawkesbury Institute for the Environment, University of Western sydney, locked Bag 1797, Penrith, nsW 2751, australia
4Department of Biology, University of Utah, salt lake city, Ut 84112, Usa
The marsupials that eat Eucalyptus in southeastern australia provide an example of animals with similar niche requirements occurring sympatrically. they certainly differ in size, ranging from about 1 kg in the greater glider (Petauroides volans) and the closely related common ringtail possum (Pseudocheirus peregrinus), to 4 kg (common brushtail possum, Trichosurus vulpecula) and up to 15 kg in the koala (Phascolarctos cinereus). all species, however, may eat considerable amounts of eucalypt foliage, often favouring the same species, and thus appear to compete for food. In order to better understand the degree of competition for food, we measured feeding by the greater glider in response to increasing concentrations of a specific group of eucalypt plant secondary metabolites (PSM), the sideroxylonals, and then compared it to results published for the other species. the greater glider was more resilient than the other species to increasing concentrations of sideroxylonals. We suggest this allows gliders to feed on leaves from the eucalypt subgenus, Symphyomyrtus, while its small size and gliding ability allow it to feed where koalas cannot, on the young leaves on top of the canopy. In contrast, the common ringtail possum is well adapted to feeding from species of the subgenus Eucalyptus, which do not produce sideroxylonals but contain less available nitrogen (availn) than do the symphyomyrtles. these ‘nutritional niches’ segregate the forest and along with other factors, such as generalist and specialist feeding strategies and differences in body size and requirements for shelter, presumably minimise competition between the marsupial species.
niche · sympatric · sideroxylonal · FPc · herbivory · Feeding ecology · marsupial