Breeding Biology and Current Status of the Grey Kangaroo, Macropus Fulginosus Fulginosus, of Kangaroo Island, South Australia.

Abstract

A distinct large dark brown kangaroo first attracted the attention of Europeans during the early exploration of Kangaroo I. in 1802-03. Although specimens were collected and the kangaroo ade- quately described, its subsequent taxonomic history was confused, and its origin long held to be Tasmania. This fallacy was not corrected until 1923-24. Subsequently the kangaroo has been re- cognized as a subspecies of the western grey kangaroo. Reproduction and growth of the young were examined in both wild and captive kangaroos. Males and females became sexually mature from age 20 months, the oestrous cycle was 34.6+ 3.2 (SD) days and the length of gestation 30.8 ± 1.8 days. Births occurred on all months of the year but were more frequent in summer. The pouch life was just over 300 days, while loss of such young usually resulted in return to oestrus after an interval of 6.3 ± 0.1 days. Disparity in sex ratio of the young was not significant. During their first year, young were measured each week. Growth curves are presented and linear or quadratic regressions fitted where applicable, together with 95% confidence limits.