Observations of Glossy Black-Cockatoos Calyptorhynchus lathami Feeding on the Seeds of Buloke Allocasuarina luehmannii

The Glossy Black-Cockatoo·Calyptorhynchus lathami is listed as a vulnerable species in New South Wales (N.S.W. National Parks & Wildlife Service 1996). An endangered population has been listed for the Riverina of New South Wales (N.S.W. National Parks & Wildlife Service 1999), and an endangered population occurs on Kangaroo Island in South Australia (Garnett 1992). Detailed studies on the species' dietary selection have been carried out at five locations in New South Wales (Llewellyn 1974, Pratt 1979, Joseph 1982, Clout 1989, M. Cameron pers. comm.) and on Kangaroo Island (Pepper 1993, 1996). Research to date has shown that the species has a relatively specialised diet consisting almost exclusively of seeds from seven species ofAllocasuarina, and occasionally wood-boring insect larvae (Higgins 1999). Records of food items other thanAllocasuarina have been treated with a degree of scepticism, owing to the possibility of misidentification of the cockatoo species or lack of evidence that seeds were actually eaten (Higgins 1999). It is of great importance to know what types of foods are eaten by the Glossy Black-Cockatoo. to determine whether its decline is related to limitation of food supply or other factors such as predation or lack of nesting hollows (Garnett et al. 1999). Understanding the dietary requirements of the Glossy Black-Cockatoo will also help clarify what species of plants need to be protected and replanted, to help the species recover. The purpose of this paper is to present the first known observations of Glossy Black-Cockatoos feeding on the seeds of Buloke Allocasuarina luehmannii. Between 9 and 18 January 2000, a small group of about a dozen Glossy Black­ Cockatoos was observed perching and calling in a small grove of Mugga Ironbarks Eucalyptus sideroxylon and Bulokes near a farm dam on Miljee Road, Rawsonville, 12 km west of Dubbo, New South Wales. The birds were obviously attracted to the dam, as some members of the flock were seen drinking there in the late afternoon. Other members of the flock were observed feeding in Bulokes close to VOL.18 (7) WALPOLE & OLIVER: SEPTEMBER 2000 Glossy Black-Cockatoo Feeding on Buloke 285 the eastern and western sides of Miljee Road. On 9 January at 1800 h EST, two birds of unknown sex were foraging alone on the seeds of a 9-m-tall Buloke at a height of 5-6 m. One bird of unknown sex was foraging in the same tree in a similar location on 13 January at 1730 h, with about 20 Galahs Cacatua roseicapilla. On 18 January between 1800 and 1840 h, three males were foraging in the same tree with about 10 Galahs and a young Eastern Rosella Platycercus eximius. Two of the males were flushed at 1750 h from a 4-m-tall Buloke about 50 m north-west of the original food tree. Chewings were later found beneath this ·tree, indicating that they had probably fed in this tree as well. A fourth male was seen foraging in a mature (approx. 8 m tall) Buloke about 60 m east of the main food-tree at the same time as the three males were feeding. No birds were observed in the area after 18 January. These observations are of significance, because they are the first published records of Glossy Black-Cockatoos foraging in Buloke. Buloke is a common tree species in the central west of New South Wales, bearing cones only during the summer months. Other species of Allocasuarina such as A. diminuta bear cones and seeds year-round, but are not as common as Buloke. Glossy Black-Cockatoos may feed on a wider range of Allocasuarina species than previously believed. More observations need to be collected on the dietary selection of the Glossy Black-Cockatoo, particularly new records of foraging in other tree species.

References Clout, N.M. (1989), 'Foraging behaviour of Glossy Black Cockatoos', Aust. Wildt. Res. 16, 467-473. Garnett, S.T. (1992), Threatened and Extinct Birds of Australia, Australian National Parks & Wildlife Service and Royal Australasian Ornithologists Union, Canberra. Garnett, S.T., Pedler, L.P. & Crowley, G.M. (1999), 'The breeding biology of the Glossy Black-Cockatoo Calyptorhynchus lathami on Kangaroo Island, South Australia', Emu 99, 262-279. Higgins, P.J. (Ed.) (1999), Handbook of Australian, New Zealand and Antarctic Birds, vol. 4, Oxford University Press, Melbourne. Joseph, L. (1982), 'The Glossy Black-Cockatoo on Kangaroo Island', Emu 82, 46-49. Llewellyn, L.C. (1974), 'New records of Red-tailed Black Cockatoos in south-eastern Australia with a discussion of their plumages', Emu 74, 249-253. N.S.W. National Parks & Wildlife Service (1996), Threatened Species of Western New South Wales, NPWS, Sydney. N.S.W. National Parks & Wildlife Service (1999), Threatened Species of Western New South Wales, rev edn, NPWS, Sydney. Pepper, J.W. (1993), 'A new food source for the Glossy Black-Cockatoo', S. Aust. Ornithol. 31, 144-145. Pepper, J.W. (1996), The Behavioural Ecology of the Glossy Black-Cockatoo (Calyptorhynchus lathami), PhD thesis, University of Michigan, Ann Arbor, Michigan. Pratt, E. (1979), 'The Red-tailed Black Cockatoo in north-eastern New South Wales', Aust. Birds 14, 36-37.

By S.C. WALPOLE and DAMON L. OLIVER, National Parks & Wildlife Service, Western Directorate, P.O. Box 2111, Dubbo, N.S. W. 2830 Received 14 April 2000 •