Demographics of tiger quoll (Dasyurus maculatus maculatus) populations in south-eastern Australia

Abstract

The tiger quoll is a large marsupial carnivore that occurs in forested habitat in south-eastern Australia. Three tiger quoll populations were trapped for up to six years and data on population parameters, including size, structure, sex ratio, adult : subadult ratio, weight, breeding characteristics, age and longevity were recorded for each population. Sex ratios (♂ : ♀) varied from 5 : 1 to 0 : 1. Population size and age structure reflected previous mortality events and social organisation traits, with all populations showing signs of instability due to disturbance events. Males did not reach full adult weight until three years of age and females until two years. Mean adult male weight was 2.81 kg ± 0.50 (s.d.) (range 2.0–4.2 kg) and mean adult female weight was 1.73 kg ± 0.22 (s.d.) (range 1.2–2.1 kg). Most females did not breed before two years of age and were recorded breeding up to four years of age. A proportion of females did not appear to breed in consecutive years. Matings were estimated to have occurred between late June and early August and births between mid-July and late August. Pouch litter size varied from 4 to 6 with a mean of 5.38 ± 0.65 (s.d.). The adult to juvenile ratio suggests that the mean number of young weaned per female is probably as low as one or two. Monitoring of four females found that the average number of young weaned was three with a range of 2–4. The maximum age recorded was five years. Population declines were found to correlate with 1080 poison baiting programmes, but not with selective logging.