Survival of Malleefowl Leipoa ocellata Chicks in the Absence of Ground-Dwelling Predators

Abstract

Malleefowl eggs were collected from the wild and incubated artificially. Week-old chicks were released into four I-ha enclosures of natural mallee vegetation. Water was placed into one enclosure, rabbits into another, seed into a third and a fourth was left unaltered. Of 20 chicks released into the non-seeded enclosures, all survived only 1-22 days (median = 4 days). Starvation was the underpinning cause of death, individuals losing body weight at a rate of up to 7% day^-1. Chicks without sufficient food were more susceptible to chilling, particularly after rain, and more vulnerable to raptors than those fed ad libitum. Of nine chicks released into the enclosure with supplementary food, only one died (as a result of chilling six days after release); all the rest survived beyond 30 days (the duration of the experiment). Subsequent transfer of surviving chicks from the enclosure with supplementary food to others containing only natural mallee vegetation resulted in their body weight decreasing up to 6.4% day^-1, sufficient to cause the death of one chick after just three days.