Ecology and Diet of Some Rodents From the Lower Montane Region of Papua-New-Guinea

Abstract

Information relating to the habitat, reproduction and diet is given for five murine rodents from the vicinity of Wau, Morobe Province, Papua New Guinea. Rattus steini was found to be present in all four habitats investigated (kunai, gardens, coffee plantations, forest), whereas R. exulans was absent from the forest; Melomys rufescens, M. lorentzi and Pogonomys macrourus were only trapped in the forest, and in low numbers. Although climatically similar to other montane regions in Papua New Guinea, the Wau area appeared to have an earlier start to the peak breeding season than elsewhere, and litter sizes seemed to be higher. The diet of Melomys species and P. macrourus appeared to be largely frugivorous (>90%), whereas Rattus species consumed a wide range of food items. While there was considerable overlap between the diets of Ratlus species, R. steini consumed more leafy material and insects, and less fruit, woody and vegetable material than R. exulans. Habitat modification by human activity in the Wau area has radically affected the diversity and relative abundance of rodent species, although it was difficult to discern any strong relationship between diet and habitat. While specific and generic identification of particular food items was not possible, an index of invertebrate diversity in the diet of rodents is suggested as a means of assessing changes in food availability, and therefore habitat change.