Juvenile behaviour and dispersal of chuditch (Dasyurus geoffroii) (Marsupialia : Dasyuridae)

Abstract

We examined the dispersal chronology and movement patterns of wild juvenile chuditch (Dasyurus geoffroii) using radio-tracking and trapping. Juveniles first began exploring outside the natal den when 17 weeks old and rapidly increased their foraging duration and distance. By the time weaning was completed during Weeks 22–24, at least 6 h was devoted to the initial foraging bout and juveniles were travelling over 500 m from their dens each night. The initial phase of dispersal occurred soon after weaning, with juveniles denning separately from their mothers yet remaining in the maternal home range. Mothers sometimes instigated this phase by abandoning their litters in the natal den. The second phase of dispersal away from the natal area was strongly male-biased, occurring when juveniles were 25 weeks old on average and covering long distances (>10 km). Most females were philopatric or settled in vacant areas near the maternal home range. Observation of captive chuditch during the weaning period provided further insights on dispersal, indicating that social play among littermates may be an important factor at this time. Aggressive wrestling rapidly escalated during the initial weeks of weaning, when wild juveniles were active yet in close proximity for most of the night. The intensity of wrestling declined before weaning was complete. Wild juveniles apparently participated in similar wrestling bouts, although possibly on a more limited scale than captives. This play behaviour potentially facilitates social cohesion among the litter at a time when juveniles are first capable of harming each other, and provides practice for fighting techniques used by adults to defend territories and secure mates.