Breeding and longevity in captive Australian sea lions Neophoca cinerea at zoos and aquaria in Australia: 1965-2003.

Abstract

Australian sea lions (Neophoca cinerea) are known to have been kept in aquaria and zoos in Australia since 1965. During that time at least 41 births were recorded, of which 19 were in Adelaide, 15 at Adelaide Zoo and 4 at Marineland of South Australia. The mean interval between successive births in Adelaide was 538.9 � 9.5 days (18.0 months; n = 10) and the mean assumed pregnancy period, including embryonic diapause, was 536.0 � 11.4 days (17.9 months; n = 9). The mean interval between parturition and presumed successful mating was 8.4 � 1.6 days (n = 5). Births occurred in all months except January, June, August and December. Figures for New South Wales and Queensland establishments are too small and scattered over time for any pregnancy periods or birth intervals to be determined. Likewise, latitudinal differences, if any, were not evident, because of the paucity of data from these more northerly places. One female at the Adelaide Zoo produced 8 pups between 1986 and 1997; she is still alive after 22 years in captivity. The youngest known-age (captive-born) female was 4 years, 8 months old when she gave birth to her first pup; and the oldest female in captivity to give birth to a pup was aged approximately 21 years, 8 months. The longest recorded captive period for a female was more than 25 years by 31 December 2003, and for a male it was 21 years, 11 months. A captive-bred female was still alive after 18 years, 2 months, 24 days; another such female died aged 18 years, 2 months, 18 days. These life spans appear to be similar to those that meagre data suggest for tagged N. cinerea in the wild.