New Zealand Journal of Ecology (1988) 11: 79- 88

Reproductive-Biology of Rabbits, Oryctolagus cuniculus (L), in Central Otago, New Zealand

Research Article
K. W. Fraser 1,2
  1. Zoology Department, University of Canterbury, Private Bag, Christchurch, New Zealand
  2. Present address: Forestry Research Centre, FRI, P.O. Box 31-011, Christchurch, New Zealand.

Autopsies on over 3000 rabbits collected between October 1980 and January 1983 provided information on the reproduction of rabbits in Central Otago. In contrast to year-round breeding elsewhere in New Zealand, reproduction was restricted to the period September-February. Distinct seasonal cycles occurred in both male and female fertility. Both sexes reached peak fertility when 12-17 months old. Female fertility is also related to carcass weight and condition. Most females (80%) experienced some pre-natal mortality, which accounted for about 30% of ovulations. Pre-natal mortality varied seasonally and was greatest in young Ç 6 months) and older (>18 months) females. Despite a larger mean litter size (6.04), the annual productivity of 23.1 young per female is about half that of other areas in New Zealand, an effect of the restricted breeding season. Comparisons for most reproductive parameters highlight the effects of seasonally severe but predictable environmental conditions in Central Otago. Poisoning success will be greatest between March and August, when there are fewer territorial and social constraints on a rabbit's ability to encounter baits.