Habitat Effects on Organ Weights, Longevity and Reproduction in the Mountain Brushtail Possum, Trichosurus caninus (Ogilby)

Abstract

Fifty-seven mountain brushtail possums. Trichosurus caninus (Ogilby), were killed and examined from a population in north-eastern New South Wales; 34 were from preferred habitat and 23 from peripheral habitat. Maximum age attained was 17 y for females and 12 y for males. Body, kidney, spleen and male liver weights were greater (P<0.05) in peripheral habitat, and female adrenal glands were heavier (P< 0.05) in preferred habitat. The mean number of corpora lutea per year of reproductive life was greater in peripheral-habitat females (1.56 ± 0.13 SE) than in preferred-habitat females (1.18 ± 0.11; P<0.05). Adult sex ratio was parity in both habitats but themean annual sex ratio of pouch young was 2.5:1 male : female in preferred habitat and 0.7:1 in peripheral habitat. The phenotypic distri-bution of transferrin differed between habitats. The data suggest that T. caninus in preferred and peripheral habitats were sufficiently distinctive in morphological, demographic, behavioural and genetic characters to be considered distinct subpopulations.