Foods of the Glossy Black-Cockatoo Calyptorhynchus lathami

Abstract

The foods of the Glossy Black-Cockatoo Calyptorhynchus lathami were determined by direct field observations and a review of the published literature. The Glossy Black-Cockatoo appears to be highly specialised, feeding on Allocasuarina throughout its range. It is known to consume the seeds of only nine plant species; most of these (89%) are from the genus Allocasuarina and one is from the genus Casuarina. In at least some of its metapopulations, the Glossy Black-Cockatoo appears to favour an Allocasuarina species that is the most profitable in terms of cone abundance, cone profitability and proximity to other resources such as nest-trees. Although Glossy Black-Cockatoos may be able to meet their immediate energy needs while feeding on an alternative Allocasuarina, they may be prevented from breeding and thereby sustaining their population. This study has highlighted the importance of identifying the favoured food-plants of the Glossy Black-Cockatoo in each of its metapopulations. It is also critical to identify the alternative plant species that are used for feeding, because these appear to allow the cockatoos to survive (though not necessarily breed) during periods when their preferred foods are in short supply. A switch to alternative foods may indicate shortage of preferred food and may result in population declines as a result of the inability of the cockatoos to breed. Protection of habitat containing both preferred and alternative food-plants should therefore be a priority for the conservation of the Glossy Black-Cockatoo.