The biology of banded (Lagostrophus fasciatus) and rufous (Lagorchestes hirsutus) hare-wallabies (Diprotodontia : Macropodidae) on Dorre and Bernier Islands, Western Australia

Sex ratio, reproduction, body condition and morphology of banded (Lagostrop hus fasciatus) and rufous (Lagorchestes hirsutus) hare-wallabies were asses sed on Dorre and Bernier Islands. Data are derived from 236 banded hare-wal labies and 161 rufous hare-wallabies captured between 1959 and 1999. The sex ratio of captured banded hare-wallabies tended to be female-biased (0.79:1 male: female) but was not a significant departure from parity. In c ontrast, pouch young tended towards a male bias at 1.35:1. Females produced 1-2 young per year. They were capable of producing young at 1000 g, but th e incidence of females carrying pouch young or lactating increased from 39% for females of 1000-1400 g to 80% for females of 1401-1800 g, then decreas ed slightly to 76% for females >1800 g. Births occurred throughout the year but there was some indication of a decline in the latter half of the year. Captured banded hare-wallabies ranged in weight from 850 to 2300 g. Animal s on Dorre Island were in significantly better body condition than those on Bernier Island, although this could be an artefact of their shorter pes le ngth. There was no evidence of sexual dimorphism and no differences in morp hological measurements taken, other than pes length, between the two island populations. The sex ratio of captured rufous hare-wallabies was close to parity at 0.99 :1 and for pouch young tended to be male-biased at 2:1. The smallest female with young weighed 1215 g, but the incidence of females carrying pouch you ng or lactating increased from 43% for females of 1215-1660 g to 61% for fe males of 1661-2015 g and 100% for females >2015 g. Females carried pouch yo ung in all months sampled (March-September) and one incidence of twinning w as noted. Captured rufous hare-wallabies weighed 600-2550 g. Body condition was similar for males and females and between islands, but smaller females of reproductive age were in poorer body condition than larger females. The re was no evidence of sexual dimorphism but pes lengths of animals on Dorre Island were significantly shorter, head lengths longer and tail lengths sh orter, than those on Bernier Island. Rufous hare-wallabies appear to show r egional variation in body size, being smaller in the wetter and warmer Tana mi/Alice Springs region and larger on the drier and cooler Shark Bay island s.