Diet of the Broad-toothed RatMastacomys fuscus(Rodentia:Muridae) in the alpine zone of the Snowy Mountains, Australia

Abstract

In seasonally snow-covered environments, larger mammalian species occurring above the snow have been shown to broaden diet breadth in winter, but below the snow in the subnivean space the relationship between snow cover and diet is quite different. The Broad-toothed Rat Mastacomys fuscus, an Australian cold climate endemic, is a specialist herbivore. The diet of M. fuscus in the alpine zone of the Snowy Mountains was studied over the snow-free period and in winter. M. fuscus showed a preference for monocots over dicots throughout the year, however, there was a greater diversity and evenness of plant taxa in the diet in snow-free seasons. In winter, fewer species dominated the diet, reducing the evenness as well as the diversity. Because of lack of cover from predators in the snow-free period, M. fuscus is constrained to foraging in areas with shrub cover, where access to preferred grasses may be reduced. By contrast, in the subnivean space, because of the shelter provided by the cover of snow, M. fuscus c...