Reproduction and breeding season of Planigale gilesi and P. tenuirostris (Marsupialia: Dasyuridae).

Abstract

Reproduction of Planigale gilesi and P. tenuirostris was studied in the laboratory and in the field in ariel western New South Wales. Females of each species have 12 teats and the pouch morphology is similar. Courting and mating behaviour and some associated vocalizations are described. During oestrus females make "mate-attracting" calls. Planigale gilesi females are in oestrus for 3 days and the oestrous cycle is 21 days. Oestrus in P. tenuirostris is for 1 day, the oestrous cycle is 33 days and the gestation period is 19 days. The breeding season in each species extends from July/August to mid-January. Males commenced spermatogenesis during July and became aspermatogenic during the following March. In free-living populations most litters were born in September and lesser numbers spread throughout the breeding season. All females attempted to produce at least one litter and some produced two litters in a season. Breeding males in the field had prominent fur discolouration from the sternal gland. The extended but seasonal breeding season of the planigales is similar to that of other arid zone dasyuricls. It coincides with the increases in food resources that occur during the spring and summer months.