Parental Investment and Rearing Schedules in the Eastern Grey Kangaroo

Abstract

Mother-young relations were studied in a wild population of eastern grey kangaroos ('Macropus giganteus') during three years. The studied population comprised approximately 100 individually-known kangaroos, all of whom were habituated to close approach on foot. The females' reproductive status was monitored on a monthly basis and half were located almost every day of the 10-day monthly field trips. About 12 females were observed regularly for recording behavioural information on the mother-young relationship. The findings have been described and discussed with reference to parental investment theory and rearing schedules. Since parental investment involves a wide range of forms of parental care; the study investigated this topic within 4 principal contexts: the general ecology of the (mothers') local population: the mothers' social positions and behaviour within the social organisation; the development of the structure of the young's behaviour and the interdependent nature of the mothers' and young's behaviour: and the mothers' and young's roles in maintaining and defining the relationship.