A mating pair makes a large platform-like nest of sticks lined with leaves standing 10-13m above the ground where the female will lay one egg (Di Giacomo 2005). During incubation the female spends close 90% of the time caring for the chick while her mate tends to hunt and provide for her. Male individuals remain in the nest only during feeding and for very short periods during incubation and rearing (Maceda 2007). The egg may be laid between August and October and hatch approximately 45days later during November-December. The lone egg may be slightly yellow or opaque white with grey spots. An egg finding reported by Di Giacomo (2005) weighed 132 grams, measured 70.8 × 59.6 mm, another egg was reported to weigh 115 g and measured 66 × 53 mm (Chebez et al. in press). Once hatched the chick remains in the nest for approximately 65-70days from mid-December to early March; and during this period the parents feed and care for the chick. After leaving the nest the juvenile or subadult bird remains with the adults for many years before venturing out completely on its own (Ferguson-Lees & Christie 2001).