Ecology of the rufous hare-wallaby, Lagorchestes hirsutus Gould (Marsupialia : Macropodidae) in the Tanami Desert, Northern Territory.II Diet and feeding strategy.

Abstract

The diet preferences and selectivity of the rufous hare-wallaby in the Tanami Desert were examined at a number of sites and over a number of seasons by microscopic analysis of faecal pellets and direct observations. Perennial grasses were the most consistent plant items in the diet. Grass seeds were seasonally important as were the seeds and bulbs of sedges. Species of dicots were also used but most represented only minor components in the diet. Several species of plant common to the area were noticeably absent from the diet. Differences in the diets between four sites of varying floristic composition and fire history were consistent with differences in vegetation cover at each site. Overall, the absolute proportions and ratios of monocots and dicots and of leaf and seed portions were strongly similar for all sites, as were seasonal changes in the proportions of the four main plant categories (monocots, dicots, seeds and fruits). These changes correlated with local rainfall. Comparisons of plants eaten and plants available indicate the hare-wallabies' preference for monocots, particularly seed and fruit components. In contrast consumption of dicots was influericed by the declining quality of other preferred plants. Insects were seasonally important in the diet and appear to be a potentially important nitrogen supplement during drier times. The feeding strategy of the rufous hare-wallaby is flexible and enables it to exploit fully food resources whose availability is often limited in both time and space. During droughts it seems likely that the species is food stressed and this could lead to localised declines.