AUSTRALIAN 380 DEBUS & EDELST AM BIRD WATCHER Etymology, Type Locality and Morphology of the Chestnut-shouldered (Burgers') Goshawk Erythrotriorchis buergersi There has long been confusion over the position of the apostrophe in the former vernacular name of the Chestnut-shouldered Goshawk Erythrotriorchis buergersi, i.e. Burger's versus Burgers' Goshawk (e.g. Beehler & Finch 1985). The specific name buergersi (possessive of the latinised name Buergersus) suggests that the man's name was Burgers, an assumption long held by SJSD. However, the original, hand-written labels on the specimens discussed in our previous paper on the subject (Debus et al. 1994) seemed to identify the collector asS. Burger (no's'), hence we used 'B'urger's Goshawk' in that paper. An historical paper that recently came to our attention (Stresemann 1923) clearly identifies the collector of the type specimen as DrS. Burgers (with the's'), physiciaiJ. to the German New Guinea Expedition 1912-1913. Hence, as indeed indicated by buergersi, the possessive should be 'Biirgers' Goshawk'. This question would now be academic, except that some non-Australasian ornithologists prefer the eponymous name. Legibility of the original labels also caused problems for correct interpretation of the type locality. Reichenow (1914) deciphered the locality as 'Miiomoboberg', but the type locality is correctly given by Stresemann (1923) and Diamond (1972) as Maeanderberg, from 'Maanderberg' in Burgers' diary. The melanistic specimen previously discussed (Debus et al. 1994) also came from this region near the middle Sepik River. It is worth noting that Stresemann's original paper provides a detailed description (in German) of these two specimens (the type and the black bird) now held in Berlin. We take the opportunity to comment on a recent specimen of the Chestnut­ shouldered Goshawk, and illustrate the similarity of that species to the Red Goshawk Erythrotriorchis radiatus (Plate 69). Chestnut-shouldered Goshawk AMNH 802008 was collected at Karimui, Eastern Highlands, Papua New Guinea on 13 July 1965 (Diamond 1972). Its sex was given as '?' (i.e. indeterminate from dissection), but 'probably female from measurements ... wing 316 [mm]'. This bird's large size relative to male specimens (Plate 69) suggests that it is indeed a female. This specimen is the immature, with a stated wing length of 320 mm, sexed as female by Brown & Amadon (1968). This diagnosis is supported by wing lengths of other specimens (males 288-301 mm, females 313-330 mm; skins/sources from Stresemann 1923, Brown & Amadon 1968 and Debus et al. 1994). The male Chestnut-shouldered Goshawk weight of 575 g (Diamond 1986) is from label data for the specimen collected by Ernst Mayr at Junzaing, Huon Peninsula, Papua New Guinea, on 25 January 1929 (Berlin no. 30.2001 = immature male in Plate 29 of Debus et al. 1994). This compares with a male Meyer's Goshawk Accipiter meyerianus of 530 g (Diamond 1986; AMNH 812149 = the smaller adult male in Plate 30 of Debus et al. 1994). A female Meyer's Goshawk from Umboi, Papua New Guinea, weighed 1100 g (J. Diamond in litt.), but there are no female Chestnut­ shouldered Goshawk weights for comparison. The similar sizes and hunting methods of these two goshawks - Chestnut­ shouldered and Meyer's- suggest niche segregation by some other means, such as habitat or altitude (Diamond 1986). Following discussion of the relationships of the Chestnut-shouldered Goshawk (see Debus et al. 1994), we offer an alternative hypothesis to that of Diamond (1986). Rather than genetic divergence from a common root, it appears that the 'old endemic' (Chestnut-shouldered) was invaded by a non­ congeneric but ecologically similar colonist (i.e. Meyer's), with consequent VOL. 15 (8) DECEMBER 1994 Chestnut-shouldered Goshawk 381 Ventral (upper) and dorsal Oower) views of Chestnut-shouldered Goshawk skins in the American Museum of Natural History, showing similarity to the Red Goshawk Erythrotriorchis radiatus (compare with any published photographs of the latter, e.g. Cupper & Cupper 1981, Hawks in Focus, Jaclin, Mildura). Left to right: juvenile male, immature male, immature female (AMNH 802008: see text), adult male. Plate 69 Photos: Photography Studio, AMNH, per M. LeCroy competition and niche differentiation. Although partly altitudinal (Diamond 1986), the nature of that differentiation remains to be determined precisely, as the two species overlap in the montane forests of New Guinea (cf. distributional data in Coates 1985). AUSTRALIAN 382 BUCKINGHAM : Pied Currawong Eating Ants BIRD WATCHER We thank Mary LeCroy (American Museum of Natural History, New York) for information on specimens, and for forwarding the colour prints kindly made by the Photography Studio, AMNH; also Professor Jared Diamond for information on specimens. References Beehler, B.M. & Finch, B.W. (1985), 'Species-checklist of the birds of New Guinea', RAOU Monographs 1, Royal Australasian Ornithologists Union, Melbourne. Brown, L. & Amadon, D. (1968), Eagles, Hawks and Falcons of the World, Country Life, London. Coates, B.J. (1985) , The Birds of Papua New Guinea, vol. 1, Dove, Brisbane. Debus, S.J.S., Edelstam, C. & Mead, D.A. (1994), 'The black morph of tbe Chestnut-shouldered (B-urger 's) Goshawk Erythrotriorchis buergersi', Aust. Bird Watcher 15, 212-217. Diamond, J.M. (1972) , Avifawza of the Eastern Highlands of New Guinea, Nuttall Ornithol. Club, Cambridge (Mass.). · --(1986) , 'Evolution of ecological segregation in tbe New Guinea montane avifauna', in Diamond, J. & Case, T.J. (Eds) , Community Ecology, 98-125, Harper & Row, New York. Reichenow, A. (1914), 'Astlir biirgersi Rchw. n. sp. ', Omith. Monatsber. 22, 29. Stresemann, E. (1923) , 'Dr. Burgers' ornitbologische Ausbeute im Stromgebiet des Sepik', Archiv f Naturgeschichte 89A(7), 1-96; (8), 1-92. By S.J.S. DEBUS' and C. EDELSTAM2 'Zoology Department, University of New England, Armidale, N.S. W. 2351 2Research Department, Swedish Museum of Natural History, Box 50007, S-104 05, Stockholm, Sweden Received 14 April 1994 • .