Ecology of Rattus lutreolus lacus in tall open forest, North-East Queensland, with emphasis on habitat use and reference to coexistant small mammals

Abstract

A mark-capture program from February to August, 1982 formed the basis of an ecological study of Rattus lutreolus lacus in tall open forest on the Paluma Range, North-east Queensland. Aspects of the ecology of three coexistent small mammals, Rattus fuscipes Melomys cervinipes and Antechinus flavipes have also been reported on. Faecal analyses indicated that R. lutreolus has a diet mainstay of grass rhizomes and stems, which is supplemented by fungi and insects. The species showed substantial diurnal activity. Microhabitat preferences were assessed in relation to the floristic and structural composition of the vegetation. Avoidance of closed forest-type microhabitat within the open forest reiterates the restriction of R. lutreolus to open forest per se. An association with dense ground cover below 1 metre was shown. Optimal microhabitat for R. lutreolus appears to equate with dense grass situations. Prolonged breeding activity throughout the year was suggested. Onset of mature breeding condition in young males occurred in May and active breeding condition was noted from the winter months of June and July until the last trapping session in August. R. lutreolus lacus has 8 nipples. This is fewer than Rattus lutreolus lutreolus which has 10 nipples and may be indicative of smaller litter sizes. Diet is suggested to be a major determinant of activity pattern, microhabitat preferences and reproductive performance of R.lutreolus. In suitable parts of the forest habitat, R.lutreolus was readily trapped and relative to the 3 other species was the most abundant small mammal. Show more