Reproduction in Wild Canids, Canis-Familiaris, From the Eastern Highlands of Victoria

Abstract

Reproduction was studied in a group of wild canids collected over four years from the eastern highlands of Victoria. While births were recorded from March to September inclusive, 78% of them took place in the winter months of June-August, with the peak occurring in July. A single breeding season each year was indicated for most, with a mean prenatal litter size of 5.5 (range 2-9). Sexually mature males were fertile throughout the year, although they exhibited a significant increase in testes weight, epididymides weight, and number of active seminiferous tubules for the months of April-June, which corresponded to the peak period of oestrus in females. The onset of first oestrus in females was variable, occurring when they were 1-4 years old, with only 36% of those less than 2 years old sexually mature. Sexual maturity in males was also variable. For animals of 10 kg (weight at initial onset of spermatogenesis) or heavier, spermatogenesis had commenced in only 63% of those less than two years old, but increased to 97% of those more than three years old. Overall this sample of canids displayed reproductive characteristics, such as a seasonal breeding season, considered typical of dingoes. However the possibility of slight changes to the original dingo breeding patterns through hybridization with domestic dogs is discussed.