Assessment of the potential for competition between two sympatric herbivores - the northern hairy-nosed wombat, Lasiorhinus krefftii, and the easterngrey kangaroo, Macropus giganteus

The northern hairy-nosed wombat, Lasiorhinus krefftii, is a critically enda ngered grazing herbivore, restricted to a single population of just 65 indi viduals in the savanna of central Queensland. Lasiorhinus krefftii shares i ts habitat with another grazing herbivore of similar body size, the eastern grey kangaroo, Macropus giganteus. This study investigated the potential f or M. giganteus to compete with L. krefftii for food. Analysis of faecal re sidues demonstrated that both herbivores consumed grass almost exclusively, with the exception of small quantities of sedges and dicotyledons. Dietary overlap between M. giganteus and L. krefftii was high, both in the consump tion of plant species (90%) and plant parts (99%), suggesting that there is potential for dietary competition. Using the distribution of faecal deposi ts for both herbivores, analysis of habitat usage by multiple linear regres sion techniques indicated that M. giganteus exhibits clear associations wit h some habitat features but proved inconclusive for L. krefftii because of their use of defecation in social marking. However, an examination of the p opulation dynamics of M. giganteus suggested that the densities reported in this study, although highly seasonal, are sufficiently low that competitio n with L. krefftii for food is currently negligible.