An endangered, picky eater
The Kangaroo Island Glossy Black-Cockatoo (Calyptorhynchus lathami halmaturinus) is one of the most diet-specialized birds in the world. This subspecies, found only on Kangaroo Island, feeds almost exclusively on the seeds from the cones of a single tree species: the drooping she-oak (Allocasuarina verticillata). They are the smallest of Australia's five black-cockatoo species, reaching about 48 cm in length. Males are brownish-black with bright red panels in their tails. Females are distinguished by patches of yellow on their head and neck, and their tail panels are more orange-red with black bars.
These cockatoos are not quiet eaters. They use their large, bulbous beaks to powerfully crack open the hard she-oak cones, and the sound of their bills clicking and the debris of chewed cones falling to the forest floor often reveals their presence. The scattered remnants of their meals, known as "chewings" or "orts," are an important sign for researchers tracking their foraging habits. The birds are selective, preferring trees that offer the highest energy return, which means a high density of cones with a good ratio of seed kernel to cone. This specialized diet makes the cockatoo extremely vulnerable to changes in its habitat.
A population on the edge
The Kangaroo Island Glossy Black-Cockatoo is listed as an endangered species. Conservation efforts began in 1995 when the population had fallen to just 158 individuals. Through intensive management, including protecting nests from predators and installing artificial nesting boxes, the population more than doubled to over 450 birds by 2023. The catastrophic 2019-2020 bushfires damaged the recovery.
The fires destroyed at least 54% of the cockatoo's she-oak feeding habitat and 38.5% of all known nests. While post-fire counts in late 2020 showed that many adult birds survived, the loss of food is a long-term threat. It will take an estimated 15 to 20 years for the burnt she-oak woodlands to recover and produce enough seeds to support the population again. In the aftermath, the cockatoos have become heavily reliant on the small, unburnt patches of their habitat and on artificial nest boxes, with their use of these boxes increasing significantly since the fires. The population in September 2024 was estimated at 422 individuals, showing a stable but no longer increasing trend. The recovery program continues to work on habitat restoration, planting thousands of she-oak seedlings to secure the future for this unique bird.