AUSTRALIAN 132 STOKES & GOH: Herald Petrels & Christmas WATCHER

Records of Herald Petrels and the Christmas Frigatebird from North Keeling Island, Indian Ocean

During 1986 we conducted seven surveys for the Australian National Parks and Wildlife Service of seabirds on this isolated island in the Cocos (Keeling) group of the Indian Ocean. Previous descriptions of the island and its are available in Stokes et al. (1984) and Gibson-Hill (1948, 1949, 1950) . The following two additions to the seabirds recorded from the island are now reported. Christmas Frigatebird Fregata andrewsi On 21 March 1986 we saw an adult female Christmas Frigatebird fly inland over the landing place at North Keeling. We are both very familiar with the from surveys of it on and there was no doubting its identity. The bird flew slowly in from the ocean at about 50 m above sea level. The distribution of the white underparts to the vent, the bright pink bill and its large size were readily apparent. Gibson-Hill (1949) refuted previous assumptions by Mathews (1914), Peters (1931) and Chasen (1933) that the Christmas Frigatebird was recorded from the Cocos (Keeling) Islands by Wood-Jones (1909), and we are sceptical of recent reports by some Cocos­ Malay people that it occasionally breeds on North Keeling. However this record leaves no doubt that occasional individuals do visit the island. Herald Petrel Pterodroma arminjoniana On the nights of26-Z7 April 1986, TS saw three Pterodroma petrels in swift wheeling flight back and forth over the lagoon entrance for two hours before dusk. Their kek­ kek-kek calls and the distribution of white on the underparts matched the description of the intermediate morph of P. arminjoniana in Harrison (1983) and Gardner et al. (1985). On 21-22 June during the next survey, P. Goh and Amat Noor bin Anthoney watched especially for the species and recorded not less than ten individuals in similar flight before dusk over the lagoon entrance. Goh caught and photographed one just after dusk as it appeared to emerge from a 'burrow' under dense fallen Coconut Palm fronds Cocos nucifera in low coconut forest on Pulo Bill, the north arm of the lagoon entrance (Plate 29). It measured (mm): exposed culmen 24.8, wing length (flattened, straightened) 285, tail length 109. The bird was released. A thorough search for a nest was not conducted in the palm-frond litter for fear of disturbing other birds, possibly on nests, and on the subsequent visit between 16-23 September 1986, TS did not record any birds at the island despite an intensive search. However one possible nest site was found with accumulated droppings at the base of a coconut tree on Pulo Bill under a thick layer of fallep fronds. The Herald Petrels of these observations probably belong to the nominate subspecies which is known to breed only on two islands in the south Atlantic Ocean and on Round Island near Mauritius in the Indian Ocean (Gardner et al. 1985, Anon. 1987). The records may therefore be the most northerly of the species in the Indian Ocean (North Keeling is at latitude 11 °50 'S). Another subspecies Pa. heraldica is widely distributed in the subtropics of the Pacific Ocean and although it is said to be slightly smaller than the nominate, the basis for continued recognition of the two races appears dubious (Bourne in Palmer 1962; P. Fullagar pers. comm.). The two observations together bring the number of seabird species recorded from North Keeling to fourteen (Feare's, 1984, summary overlooked the Bridled Tern Sterna anaethetus specimen collected by Gibson-Hill 1948), eleven of which breed on the island. The number of breeding species would increase to twelve if the Herald Petrel is confirmed as breeding. Therefore the island is undoubtedly of unique importance to Indian Ocean seabirds and has perhaps the widest variety of species of any island VOL. 12 (4) DECEMBER 1987 STOKES & GOH: Herald Petrels & Christmas Frigatebird 133

Herald Petrel, intermediate morph, North Keeling Island, Indian Ocean Plate 29 Photo: Peter Goh in the Ocean. In recognition of this, a management program is being developed for the island by the Australian National Parks and Wildlife Service in consultation with the local Council and the Administration. The aim is to ensure that traditional hunting of the Red-footed Sula sula, together with the use of the island for tourism and other purposes, is regulated to ensure that the impact upon the numbers of the birds and the viability of their populations is minimal. References Anon. (1987) , 'Round Island rebounds after pests removed', World Birdwatch 9(3), 1-2. Chasen, F.N. (1933), 'Notes on the birds of Christmas Island (Indian Ocean)', Bull. Raffles Museum 8, 55-87. Feare, C.J. (1984), 'Seabird status and conservation in the tropical Indian Ocean', in /CBP Tech. Pub. no. 2. Gardner, A.S., Duck, C.D. , & Greig, S. (1985) , 'Breeding of the Trinidade Petrel Pterodroma arminjoniana on Round Island, Mauritius', Ibis 127, 517-522. Gibson-Hill, C.A. (1948), 'The Island of North Keeling', J. Malay Br. Roy. As. Soc. 21 , 68-108. -- (1949), 'The birds of the Cocos (Keeling) Islands, Indian Ocean', Ibis 91, 221-243. --(1950), 'Notes on the birds of the Cocos (Keeling) Islands', Bull. Raffles Museum22, 212-270. Harrison, P. (1983), Seabirds, An Identification Guide, Croom Helm, London. Mathews, G.M. (1914), 'On the species and subspecies of the Fregata', Aust. Avian Record 2, ll7-12l. Palmer, R.S. (Ed.) (1962) , Handbook ofNorth American Birds, vol. 1, Yale University Press, New Haven. Peters, J.L. (1931), Checklist of the Birds of the World, Vol. I, Harvard University Press, Cambridge, Massachusetts. Stokes, T., Shiels, W. & Dunn, K. (1984), 'Birds of the Cocos (Keeling) Islands, Indian Ocean', Emu 84, 23-28. Wood-Jones, F. (1912) , Coral and Atolls, Lovell Reeve and c;o, London. By 1DNY SIDKES' and PETER GOH2 1 Australian National Parks and Wildlife Service, G. PO Box 8, Canberra, A.C.T 260I 2 Australian National Parks and Wildlife Service, Christmas Island, Indian Ocean 6798•