Threatened Species - Yellow-tailed Black-Cockatoo
Critically Endangered Eyre Peninsula Yellow-tailed Black-Cockatoos
Yellow-tailed Black-Cockatoos Calyptorhynchus funereus are found throughout south eastern Australia in SW Queensland, eastern NSW, Victoria, Tasmania, Bass Strait islands and southern South Australia. Yellow-tailed Black-Cockatoos are not listed as nationally threatened, however in South Australia, Yellow-tailed Black-Cockatoos are considered Vulnerable under the National Parks and Wildlife South Australia (NPWSA) Wildlife Schedules 2000. The Eyre Peninsula Yellow-tailed Black-Cockatoo population is isolated from other mainland and island populations (including Kangaroo Island) and has undergone dramatic decline since European settlement. Consequently, the Eyre Peninsula Yellow-tailed Black-Cockatoo population is now recognised as critically endangered. Historically there were hundreds…anecdotal evidence from farmers on lower Eyre Peninsula in South Australia, in the early 1900s suggest that flocks of approximately 100 Yellow-tailed Black-Cockatoos used to be seen feeding in the heath between the Koppio Hills and Marble Range. They declined silently...the status of the population remained largely unknown until studies conducted by Nias (1987) & Possingham (1984) revealed that fewer than 40 birds remained. Habitat loss is believed to be the principle cause of historic population decline. In 1998 only between 19 and 21 birds remained on the Eyre Peninsula. Current census data for 2004 has the wild population between 30-40 individuals. At this size, the population requires broad based assistance to prevent it from becoming extinct in the near future. What is being done?Research has been conducted since 1998 to identify current threats to this unique population. This information is then used to guide "on ground" activities to maximise their benefit to the cockatoo population. Current threats identified include:
See Yellow-tailed Black-Cockatoo brochure (550Kb PDF) Habitat Use / Movements
The Eyre Peninsula Yellow-tailed Black-Cockatoos roam over a large portion of Eyre Peninsula, South Australia. A knowledge of where the birds are throughout the year is critical for identifying any possible threats the birds may face. The cockatoos breed over summer in the Sugar Gum woodlands of the Koppio Hills, lower Eyre Peninsula. All the nests detected have been in woodland remnants on private land. Much of the suitable breeding habitat has been cleared from the Koppio Hills and the continued loss of large trees is of concern. The birds are traditional users of the habitat and tend to return to the same area each year. By around late April, any chicks produced have usually fledged and the flock leaves the Sugar Gum breeding ground. The cockatoos migrate north about 250 km to the granite inselberg country around Wudinna. The birds remain in the area until late October when they make the return journey south for breeding. More research is required to better understand the exact location of the birds over winter and early spring. Records taken by property owners have provided an invaluable insight to the flocks movements across Eyre Peninsula. This community network has enabled researchers to locate the flock more rapidly. Studies into the habitat use by the cockatoos have shown that the fragmented nature of the breeding habitat may be increasing the vulnerability of the population to predators such as wedge-tail eagles and peregrine falcons. Strategic revegetation providing habitat links across the landscape is likely to be of significant benefit to this population. Diet
Research into the diet of the cockatoos has found they consume a variety of foods including wood boring insect larvae and seeds from woody cones. Birds have been observed chewing to find grubs in a variety of mallee, eg White Mallee Eucalyptus gracilis near Minnipa in the northern winter habitats and under Sugar Gum Eucalyptus cladocalyx bark on lower Eyre Peninsula, South Australia. Insect larvae from within yakka Xanthorrhoea semiplana spikes are also a sought after meal. With the loss of native vegetation, seeds from the introduced Aleppo Pine Pinus halepensis have become a major source of food for the cockatoos. Chewed cones under the pine trees are a valuable indicator of the birds presence in an area. The colour of the chewed cones can also indicate how recently they visited the tree. Native plant seeds consumed by the cockatoos include those from Wrinkled Hakea Hakea rugosa, Elm-seed Hakea Hakea cycloptera and occasionally green Acacia gillii seeds. The chewed hakea cones and the pruned tips of the shrub are a clear indicator that the cockatoos have visited The information obtained from the dietary research is assisting in the selection of plant species for revegetation programs in key areas. With the control of invasive pines accelerating on lower Eyre Peninsula, South Australia, the research has also highlighted the need to retain some stands of Aleppo Pines until revegetated areas can support the population. The Department for Environment and Heritage is working with the Lower Eyre Pest Management Group to develop Strategic guidelines for Aleppo Pine control and Eyre Peninsula Yellow-tailed Black-Cockatoo conservation. Breeding Success
Nest monitoring has been conducted to determine the number of cockatoo chicks surviving to fledge the nest and thus add to the population. Nest monitoring also identifies the possible causes of nest failure and therefore identifies recovery acions to reduce nesting mortality. See breeding results (50Kb PDF) Release TrialsAs Yellow-tailed Black-Cockatoos tend to lay two eggs but only ever rear one chick, the second egg from several nests were collected for hand rearing. The intention was to raise these chicks which would normally not survive and add them back to the wild population. In 1998/99 breeding season, four eggs were collected from nests and hand reared at the Gorge Wildlife Park near Adelaide, South Australia. At nearly twelve months of age, three of the four juvenile birds were released to join up with the flock. Unfortunately, one of the released birds was taken by a fox whilst another disappeared without a trace. The third bird was recaptured and retained for captive breeding. The trial release program, whilst appearing unsuccessful, revealed a lot of areas for improvement that will now increase the likely success of any future release attempt. The release exercise has highlighted the need for more trials in this area. It is envisaged that trials with less threatened populations of black cockatoos will help develop a suitable release strategy for the Eyre Peninsula population. There are currently seven Eyre Peninsula Yellow-tailed Black-Cockatoo's at the Gorge Wildlife Park. Project AchievementsFuture WorkContinue to: Program Support
AuthorsJason van Weenen, Scientific Officer, Threatened Species, Department for Environment and Heritage ContactIf you have seen a Yellow-tailed Black-Cockatoo on the Eyre peninsula or require further information regarding this critically endangered population, contact Sarah Way, Eyre Peninsula Yellow-tailed Black-Cockatoo Project Officer. Jason van Weenen, Scientific Officer, Threatened Species, Department for Environment and Heritage |
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