Breeding season of female wild rabbits in natural populations in the Riverina and Southern Tablelands districts of New South Wales

Abstract

The breeding seasons in females in natural populations of wild rabbits in the Riverina and Southern Tablelands districts of New South Wales have been studied. The availability of green food plants was a necessary prerequisite for the initiation of breeding and for the maintenance of maximum response. The drying or seeding of pasture at first caused reduced breeding and later resulted in either an extremely low level of breeding or complete cessation. A well-defined autumn-spring breeding season occurred in the Riverina district. In the Southern Tablelands, the main breeding period started in the late winter (July) and continued until early summer when pastures dried out. A relatively short anoestrus followed. Restoration of pasture conditions apparently ideal for rabbit breeding occurred in early autumn as a result of late summer-early autumn rains. The consequent breeding response was, in fact, only abortive. This was believed to be due to a type of reproductive exhaustion or refractory period causally associated with the brevity of the preceding anoestrous period that followed the intensive spring-summer breeding period.