Maternal Strategies of Phascogale-Tapoatafa (Marsupialia, Dasyuridae) .2. Juvenile Thermoregulation and Maternal Attendance

Abstract

When juvenile Phascogale tapoatafa first release the maternal teats and are left in the nursery nest (c. 48 days of age), they lack fur, weight about 4 g, and are poikilothermic. Thermoregulation of wild litters was measured using a temperature-sensitive radio-transmitter inserted into the huddled litter after the mother's departure at night. On cold nights (less-than-or-equal-to 10-degrees-C), juveniles lose heat rapidly in the absence of their mother, with litter temperatures declining to an average of 6-degrees-C in 4 h. Litter temperatures of 3-degrees-C were common. Maternal attendance (incubation) is frequent and of long duration during the early-nesting period, then decreases as juveniles acquire fur and develop endothermy. The mother contributes to litter thermoregulation and security by constructing a large nest of bark, feathers and fur in a tree cavity with a small entrance hole.