AUSTRALIAN 144 MACKAY: Papuan in North Queensland WATCHER

Papuan Harrier Circus spilonotus spilothorax in North Queensland, with Comments on Plumages

Previous records of the Papuan Harrier Circus spilonotus spilothorax in Australia are rather unsatisfactory. Simpson & Day (1984) stated 'One record from Darwin, N.T.', presumably since 1981 as it was not mentioned in Blakers et al. (1984). The record, not properly documented with details or a description, was a sighting of a black and white harrier by J.L. McKean (pers. comm.) in the early 1980s; it apparently formed the basis for inclusion in Slater et al. (1986) . Mitchell (1988) listed a record for the Daintree River, north Queensland, 10 August 1988. The unusual sighting report form, submitted by J. Munro, describes the bird as a subadult nearly turning into full male plumage: back streaked brown and grey; pale underneath with black wing-tips; black head and nape. The bird was in sugar cane. Aumann (1989) described a harrier near Darwin, 3 September 1986, as most similar to an adult male Papuan Harrier except that its 'hood' and breast streaking were very dark brown rather than black, and its underwings lacked the dark trailing edges; perhaps it was in subadult and/or very worn plumage, with faint trailing edges to the wings. Smith (1991) reported a probable adult male Papuan Harrier at Darwin on 8 August 1988. W.T. Cooper (pers. comm.) observed an adult male black and white harrier between Lake Eacham and Malanda (Qld) on 14 September 1987: only the ventral surface was seen, and the black of the head and neck ended on the upper breast. Finally, a Papuan Harrier was reported for Badu Island, Torres Strait, 5 September 1989 (no other details: Anon. 1990). Badu is one of the larger islands, in Australian territory, about half way between New Guinea and Australia. I observed an adult male Papuan Harrier near Tolga on the Atherton Tableland, north Queensland, on 1 July 1988, and near Atherton on 18 July 1989. No drawings or photographs were taken as I have been familiar with this species in Papua New Guinea since 1965. I have many photographs of this species from Papua New Guinea, currently on loan to the RAOU and the National Photographic Index of Australian Wildlife, and I observed it recently (January 1991) in Papua New Guinea. My diary notes for 1 July read: [Papuan] Harrier. An adult male with the black throat sharply cut-off. Flew parallel to road and then off over a stubble field. About 4 krn N of Tolga. Typical adult male as in PNG. My notes for 18 July read: Just out of Atherton on Malanda Road ... c. 1430 h saw ad. male Papuan Harrier over open fallow field. This Papuan Harrier was a typical male as in PNG. Also as in some males this one had a bit of streaking on the side of the body under the wings. The first bird was 70-80 m from the road, and on both occasions the weather was fine and sunny and 10 x 50 binoculars were used. Both were obviously harriers from their shape and flight behaviour, e.g. slender build with long wings and tail, low sailing flight on upswept wings. They were identified as Papuan Harriers because they were about the size of a male Swamp Harrier Circus approximans, they had black trailing edges to the secondaries (a diagnostic feature of this species: Coates 1985), and because they lacked the broad white leading edges to the wings possessed by adult male Pied Harriers C. melanoleucos. VOL. 14 (4) DECEMBER, 1991 MACKAY: Papuan Harrier in North Queensland 145

In both birds at Atherton the black on the throat ended abruptly, whereas I believe that in younger birds the black ends as a jagged line with some streaking down onto the breast. I consider that one of the birds I saw was a mature adult, the other almost so with traces of immaturity (slight streaking on its sides). Beehler et al. (1986) illustrated the sharp cut-off and lack of breast streaking in 'adult males from the Highlands population'. These possible age characters in males require investigation, as they have apparently not been noted on any museum skins of this species (B.J. Coates pers. comm.).

Figure 1. Schematic diagram of dorsal surface of adult male Papuan Harrier (left) and Pied Harrier (right). Drawing: R.D. Mackay

A potential problem for bird-watchers in northern Australia is to distinguish the adult male Papuan Harrier from the adult male Pied Harrier. The latter migrates to South-East Asia, although it has not been recorded in Indonesian islands other than Borneo. The Pied Harrier is a small species (c. 43 em long), which should be readily apparent in the field if other raptors are present for comparison. The best character for separating adult males of each species apart from size, is the presence or absence of a dark trailing edge to the wing, as noted by Coates (1985) . In the Pied Harrier there is less black on the upperwings: the pattern is similar to Papuan, but with a broader white area on the inner leading edge of the wing and no dark trailing edge (B.J. Coates obs. and photos; see Figure 1) . The Eastern Circus spilonotus spilonotus, another harrier with pied male plumage and a migrant to South­ East Asia, must also be considered. However, it has not been recorded closer to Australia than Borneo, and it is more streaked and lacks the solid black hood of its Papuan race (e.g. King et al. 1975, Beehler et al. 1986) . On present information it appears that the Papuan Harrier is a rare visitor to the Northern Territory (Top End), northern Queensland (Cape York) and islands in Torres Strait: those parts of Australia closest to New Guinea. This might be expected in view of the ability of harriers to make sea crossings (e.g. Bass Strait: Blakers et al. 1984). It may be significant that dated sightings for Australia fall in the austral winter and early spring, perhaps suggesting some post-breeding dispersal from New Guinea (cf. Coates 1985: breeding March-May). If such dispersal mainly involves juveniles, as would seem likely, then perhaps some birds remain undetected among juvenile and female Swamp Harriers in Australia until males moult into adult plumage. However, AUSTRALIAN 146 MACKAY: Papuan Harrier in North Queensland BIRD WATCHER

most records of the Papuan Harrier in Australia are unconfirmed and further details of Australian sightings are required. Conversely, the true status of the Swamp Harrier in New Guinea warrants investigation as there are few reliable records, most sightings apparently being referable to juvenile/immature plumages of the Papuan Harrier which are poorly understood. The status of harriers in New Guinea cannot be clarified until many more specimens (including live birds for banding purposes) are closely examined and measured. Additional data, kindly supplied by B.J. Coates, enable some information to be added to that concerning the juvenile Papuan Harriers shown on Plate 143, p. 119 of Coates (1985). A pair of Papuan Harriers, a melanistic male (all blackish except for a pale tail and white upper tail coverts) and a dark brown female, were found nesting in the Wahgi Valley in 1978 by R. Campbell. The nest contained an addled egg and two well-grown young on 10 May. The egg measured 46.5 x J7 mrn, and the two young were taken to the Baiyer River Sanctuary. Coates photographed them in October 1978 and January 1979, the latter occasion when they were almost a year old (Coates' Plate 143). In August 1980 and April 1981 Coates noted some slight plumage changes. Subsequently one bird killed the other, and in September 1986 when the survivor was 8'h years old, Coates took the following description: Female? - all brown, slightly lighter (buffier) on head; nape and shoulder patch (on scapulars) whitish buff; upper tail-coverts whitish buff; tail lighter brown with several dark brown bars; iris dark; legs pale yellowish. Adult female Papuan Harriers thus have a dark brown morph, corresponding to the black morph in adult males. The pale scapulars should enable such females to be separated from Swamp Harriers. Thanks are due to Peggy Mitchell for supplying a copy of J. Munro's unusual sighting report form, to Brian Coates and Bill Cooper for their information, to anonymous referees for their comments, and to the editor for assistance in the preparation of this note.

References Anon. (1990) , 'Twitchers' corner', RAOU News!. 85, 4. Aumann, T. (1989), 'A possible record for the Spotted Marsh Harrier in the Northern Territory', Australasian Raptor Assoc. News 10, 35. Beehler, B.M., Pratt, T.K. & Zimmermann, D. A. (1986), Birds ofNew Guinea, Princeton University Press, Princeton, New Jersey. Blakers, M., Davies, S.J.J.F. & Reilly, P.N. (1984), The Atlas ofAustralian Birds, Melbourne University Press, Melbourne. Coates, B.J. (1985) , The Birds of Papua New Guinea, MJlume 1, Non-Passerines, Dove, Brisbane. King, B.F. , Dickinson, E.C. & Woodcock, M.W. (1975), A Field Guide to the Birds of South-East Asia, Collins, London. Mitchell, P. (1988), 'Unusual sighting reports, series 71', Bird Observer 680, 112-113. Simpson, K. & Day, N. (1984), The Birds of Australia, Lloyd O'Neil, Melbourne. Slater, P. , Slater, P. & Slater, R. (1986) , The Slater Field Guide to Australian Birds, Rigby, Sydney. Smith, L. (1991), 'Another possible Papuan Harrier over the Northern Territory', Australasian Raptor Assoc. News 12, 29-30. By ROY D. MACKAY, C.M.B. 16, Paluma, Queensland 4816 Received 26 February 1991 •