Diet of the eastern chestnut mouse (Pseudomys gracilicaudatus). II Seasonal and successional patterns

Abstract

The seasonal and successional changes of the diet of P. gracilicaudatus was examined by microscopic analysis of faecal pellets collected in a coastal heathland of New South Wales. Overall, five major dietary items (leaf, stem, seed, fungi and insect), which accounted for more than 95% of the total diet, showed significant seasonal changes. The Mantel test demonstrated that the diet of P. gracilicaudatus significantly differed between all seasons. At different successional stages of the habitat, the consumption of the dietary items leaf, stem and insect were significantly different. The overall diet at the middle successional stage was significantly different from those at the other two stages, between which the diet was not significantly different. However, when the comparison was made in summer, the differences between the young and old stages were significant for most dietary items and overall. As a result, a significant interaction of season and regeneration age on the diet of P. gracilicaudatus occurred. Such an interaction also extended to dietary diversity and among-individual variation. These results indicate that P. gracilicaudatus possesses an opportunistic foraging strategy that has evolved in a variable environment. They also have important take-home messages that any interpretation of observed ecological patterns and the design of future research for any species that appear to have evolved with such fire regimes must take into account such an interaction of season and vegetation succession.