An Ecological Study of Sminthopsis carasicaudata (Marsupialia : Dasyuridae) III.* Reproduction and Life History.

Abstract

Reproduction in Sminthopsis crassicaudata was studied at three sites in south-eastern Australia: Werribee, Vic., Fowlers Gap Station, N.S.W., and Willandra National Park, N.S.W. At Werribee, the breeding season covered the period July-February. Individual females attempted to raise two litters during this season; there was no significant difference between the numbers of young weaned from first and second litters. Some females bred in two seasons, but it is unlikely that any males did so. At Fowlers Gap Station, breeding occurred in the same months as at Werribee, but there was variation between years in the onset of reproduction. At Willandra National Park, breeding occurred in the period June-December. There was no evidence of unseasonal, opportunistic breeding at either of these sites.

As judged by pit-trapping, populations of invertebrate animals peaked in summer at Fowlers Gap Station, and probably at Werribee. Changes in weight and fat reserves also suggest that autumn and winter were periods of depressed food supply.

The adaptive significance of the double-litter system and polyoestry is discussed. It is concluded that the overall biology of S. crassicaudata reflects adaptation to a fluctuating food supply.

* Part II, Aust. Wildl. Res., 1978, 5, 163–82.