55 AUSTRALIAN FIELD ORNITHOLOGY 2003, 20, 55-58 Cinnamon cinnamomeus on Christmas Island: A New for Australian Territory

MIKE CARTER 30 Canadian Bay Road, Mount Eliza, Victoria 3930 (Email: [email protected])

Summary

This is an account of the first Australian record of the Cinnamon Bi~tern Ixobrychus cinnamomeus. The bird, an adult female, died soon after being found alive but in an emaciated condition. The specimen, with the registration number B24113, is now retained in Museum Victoria, Melbourne.

The discovery A living, but very sick, bird was found by Peter Green and Azmi Yon at about 1500 h on 22 February 2002 on a track within the Christmas Island National Park (about 10°29'S, 105°38'E), near the geographical centre of the island in an area of tall rainforest. Within an hour, it was passed to Max Orchard, Park Manager, for rehabilitation. The bird was in an emaciated state, would not feed despite several attempts, and was dead by the next morning. On the morning of 11 March 2002, whilst I was visiting Christmas Island with Sean Dooley, Max Orchard asked me to identify the frozen corpse. I identified it as a Cinnamon Bitternlxobrychus cinnamomeus, a species not listed for Christmas Island and with no previous records from elsewhere in . He asked me to document the occurrence. That afternoon I measured and photographed the specimen and wrote a description. About a week later, David James examined it and took another set of measurements with more sophisticated equipment.

Description The bird was a typical small bittern, with a long dagger-like bill and longish legs, similar in shape to the I. minutus (Plate 10). It was noticeably smaller than a specimen of the I. jlavicollis retained in the same freezer and therefore available for direct comparison. Upperparts from the cheeks, sides of neck and nape to the tip of the tail, including all wing-coverts and flight-feathers, were bright rufous (or cinnamon) with a little inconspicuous buff spotting and darker edging to the greater coverts and scapulars. The colour was fairly uniform throughout but richest on the primaries, which had blue-black shafts. The forehead was purplish black becoming paler across the crown and gradually shading into the rufous of the nape. The lares and skin around the eyes were yellowish buff. Ground colour of the underparts was yellowish buff patterned as follows. A stripe formed by a mixture of black and cinnamon extended down the centre of the foreneck from the chin to the upper breast. A series of similarly coloured streaks formed two or three shorter, broken lines each side of this central line. On the shoulder, each side at the base of the neck was a tuft of large, prominent black feathers, shaped somewhat like elongated diamonds, narrowly fringed yellow. Although partially AUSTRALIAN 56 CARTER FIELD ORNITHOLOGY

Table 1 Measurements of from Christmas Island in mm. Source: (1) Taken by MC with a metal rule as defined in Marchant & Higgins (1990); (2) taken by David James with a metal rule, butted rule and dial calipers as defined in Marchant & Higgins (1990); (3) taken by Wayne Longmore [Bill length is measured from skull, not exposed culmen as in (1) and (2)].

Source Wing Tail Bill Tarsus Toe (1) 142 45 49 50 58 (2) 147 45 48.5 49.4 54.5 (3) 142 44 56.9 49.7

hidden by the carpal joint of the wing, these were a significant feature of the bird. Similarly patterned smaller, less striking feathers formed streaking on the flanks and belly. The underside of the remiges was whitish with a pinkish tinge and the underwing-coverts were yellow with sparse dark mottling. The bill was bicoloured, mainly yellow but broadly black on the top of the upper mandible and along the cutting edge of the lower mandible. Thus it appeared striped like the throat. The legs were mostly green with some brown scales. The upperside of the toes was darker and the soles were yellow. The overall length as determined by Wayne Longmore at Museum Victoria, Melbourne, was 343 mm. Other measurements are given in Table 1.

Identification Worldwide there are eight species of small bittern, all in the genus Ixobrychus. Four occur in the Oriental and Australasian regions, likely sources for vagrants to Christmas Island. These are Cinnamon Bittern, Little Bittern, I. sinensis and Schrenck's Bittern/. eurhythmus. Only one, the Cinnamon Bittern, has the uniform rufous colouration described here and no other has the tuft of yellow-fringed black feathers on the shoulder (Hancock et al. 1984). Moreover, the other species found in these regions have black remiges (Hancock et al. 1984). The dark crown, gular stripe and streaking on the neck identify the bird as an adult female.

Discussion The Cinnamon Bittern ranges throughout , South-East , , the Philippines, south-eastern , Taiwan and the small southernmost islands of Japan (Clements 1991, MacKinnon & Phillipps 1993, Coates et al. 1997, Kanouchi et al. 1998). With respect to range, the text and map in Hancock et al. (1984) appear to have several errors: the southernmost parts of its range in Sumatra and Java are omitted, whereas it is shown and stated to be present in areas in the north (Korea and Manchuria) from which it is absent. Close to Christmas Island, it is a common resident of freshwater swamps and rice paddies throughout the Greater Sundas (MacKinnon & Phillipps 1993). Populations in the north of its range are migratory, wintering in the Philippines, Borneo and Sulawesi (Hancock et al. 1984, Coates et al. 1997). Migrants returning VOL. 20 (2) JUNE2003 Cinnamon Bittern on Christmas Island 57

Cinnamon Bittern: 1be Christmas Island corpse, 11 March 2002 Plate 10 Photo: Mike Carter north in the boreal spring arrive in Hong Kong well before mid April (Hancock et al. 1984). The species is not listed in Christidis & Boles (1994) and there have been no reported occurrences since then, so this is a new bird for Australian Territory. This account has been reviewed and accepted by the Australia Rarities Committee, case number 332 (Tony Palliser in !itt. 5 July 2002). The frozen body was sent to Museum Victoria in Melbourne where it was prepared as a study skin (retaining the trunk of the skeleton), with an open wing attached, registration number B24113. Heart, liver and some muscle tissue (specimen MV3781) have also been retained. The bird's appearance coincided with the monsoon season but there had been no recent cyclones or other exceptional weather. There was, however, an influx to Christmas Island of of several species including Great EgretArdea alba, Cattle EgretA. ibis, Striated HeronButorides striatus (two or three individuals of the Javan race), Malayan Night Gorsachius melanolophus, a small unidentified Ixobrychus bittern and Black Bittern (at least two) (Glenn Holmes pers. comm., David James pers. comm., Sean Dooley pers. comm., MC pers. obs.). There are too few data from Christmas Island to know whether such an influx was an unusual or a regular event. In February, during the wet season, roadside vegetation in the area where the bird was found may provide some cover and temporary sustenance for a small bittern but there is no suitable wetland habitat for the long-term survival of this species anywhere on Christmas Island. It is assumed, therefore, that this individual was a vagrant from Indonesia, perhaps a wandering resident or a victim of reverse migration. Java is just 360 km to the north. AUSTRALIAN 58 CARfER FIELD ORNITHOLOGY

Acknowledgements I thank Max Orchard for inviting my comments on the specimen and providing the details of the find. I also thank David James for the second set of dimensions and him, Glenn Holmes and Sean Dooley for sharing their observations. Rory O'Brien kindly provided Museum Victoria's measurements and skin preparation details.

References Christidis, L. & Boles, WE. (1994), The and Species of Birds of Australia and its Territories, RAOU Monograph 2, Royal Australasian Ornithologists Union, Melbourne. Clements, J.F. (1991) Birds of the World: A Check List, Ibis, Vista, California. Coates, B.J., Bishop, K.D. & Gardner, D. (1997), A Guide to the Birds of Wallacea, Dove, Brisbane. Hancock, J., Kushlan J., Gillmor, R. & Hayman, P. (1984), The Herons Handbook, Croom Helm, Beckenham, Kent (U.K.). Kanouchi, T., Abe, N. & Ueda, H. (1998), Wild Birds ofJapan , Yama-Kei, Tokyo (in Japanese). MacKinnon, J. & Phillipps, K. (1993), A Field Guide to the Birds of Borneo, Sumatra, Java and Bali, Oxford University Press, Oxford. Marchant, S. & Higgins, P.J. (Eds) (1990), Handbook of Australian, New Zealand and Antarctic Birds, vol. 1, Oxford University Press, Melbourne. Received 31 January 2003 •