Breeding biology of captive, reintroduced and wild greater bilbies, Macrotis lagotis (Marsupialia : Peramelidae)

Abstract

The breeding biology and growth of Macrotis lagotis was investigated using captive stock in Alice Springs and Dubbo and a reintroduced population at Watarrka National Park. Individuals of M. lagotis reached sexual maturity at about six months of age and continued growing until about 18 months old. Pouch life and weaning took approximately 90 days and females produced up to four litters per year. Litters comprised 1–3 young. Average litter size at pouch exit ranged from 1.0 to 1.88, depending on whether animals were studied in captivity or under reintroduced free-range conditions. Females commonly continued breeding past the age of four years and longevity extended to 10 years in captivity. In comparison, the most animals caught in the wild were estimated to be less than 12 months old. Animals in the reintroduced population exhibited a greater reproductive output than the captive populations examined. However, survivorship was far greater for animals in captivity. An intensively managed captive population may achieve a three-fold increase in size in a 12-month period.