Population regulation and dispersion of the smoky mouse, Pseudomys fumeus I. Dietary determinants of microhabitat preference

Abstract

Habitat preferences of four species of small mammals were studied on a 7.5-hectare trapping grid in a subalpine heathland/woodland complex on Mt William, western Victoria. Animals did not show strong spatial separation and differences in dispersion appeared to represent response to some feature of habitat. Floristic cues were good predictors of preference for Rattus lutreolus, Antechinus swainsonii and Pseudomys fumeus. Structural factors might also be important for R. lutreolus and A. swainsonii. The entire grid was suboptimal for Antechinus stuartii. Pseudomys fumeus was mycophagous during winter and, in the summer breeding season, principally ate seeds and bogong moths. Habitat preferences appear to reflect selection for those areas providing a year round source of high quality food rich in nitrogen. The transition period between the end of production of fungal sporocarps and prolific subalpine flower and seed production during summer may be particularly important as preferred areas provide fungi and seeds over longer periods, and food for bogong moths during their annual migration.