Ecology of Australian tropical rainforest mammals. III. The Cape York rat, Rattus leucopus (Muridae : Rodentia)

Abstract

This is the first detailed ecological study of the Cape York rat, Rattus leucopus, a small rodent found on the Cape York Peninsula, North Queensland, Australia. A total of 296 animals was captured 1135 times in rainforest at Iron Range during a capture–mark–recapture study from 1989 to 1991. Compared with other native species of Rattus in more variable habitats, populations of R. leucopus were relatively stable: adjusted mean numbers on the traplines exhibited a 2.3–2.6-fold change. This stability may be related to the apparently more stable food supply in tropical rainforest. Evidence from this study indicates that populations are limited by food availability: male reproductive condition peaked in December when fruit availability was high; and mean population abundance significantly increased in moist areas where food supply was apparently higher. R. leucopus was nocturnal, terrestrial, omnivorous, and nested communally in burrows. Breeding occurred throughout the study. Young became trappable at the age of 22 days. Reproductive maturity was reached at the age of three months. Females gave birth to their first litters when they were at least four months old, and continued to breed into their second or third year.