133 AUSTRALIAN Field Ornithology 2011, 28, 133–135 Black Taken by

JERRY OLSEN1, A.B. ROSE2 and WALTER E. BOLES3 1Institute for Applied Ecology, University of Canberra, Australian Capital Territory 2601 (Email: [email protected]) 2Associate, Australian Museum, 6 College Street, Sydney, New South Wales 2010 (Present address: 61 Boundary Street, Forster, New South Wales 2428) 3Australian Museum, 6 College Street, Sydney, New South Wales 2010

Summary. Remains of a Black Falcon Falco subniger wing, among superficially similar wing remains of Australian Ravens Corvus coronoides, were found as prey at a Peregrine Falcon F. peregrinus eyrie in December 2006 at high altitude near Canberra, Australian Capital Territory. This item was among other large, dangerous prey items taken by Peregrine at this altitude and habitat, where small prey are less available.

The Black Falcon Falco subniger and Peregrine Falcon F. peregrinus are, sex for sex, about the same size and weight, although the female Peregrine has more robust feet, usually taking one band size larger (or sometimes half a size larger) than the female Black Falcon (see Marchant & Higgins 1993; Debus & Olsen 2011; Schoenjahn 2011). Peregrine Falcons are known to take other, usually smaller, raptors, including the Brown Goshawk Accipiter fasciatus, Collared Sparrowhawk A. cirrocephalus and Nankeen Kestrel F. cenchroides, as prey occasionally (Marchant & Higgins 1993; Olsen et al. 2004). A study of the Peregrine Falcon in the Australian high country found a high proportion of ravens Corvus spp. in the diet (Olsen et al. 2004). Further collections of prey remains from one of those cliff eyries, at Corin Dam near Canberra in the Australian Capital Territory, found additional raven remains (Table 1). On 19 December 2006 JO collected a sample that contained several Australian Raven C. coronoides wings (primary feathers attached to wing-bones). The sample was forwarded to ABR for identification; he noticed that one superficially raven-like wing was slightly different. Suspecting Black Falcon, he forwarded the wing and attached bones to WEB, who compared the item with museum specimens and confirmed it as Black Falcon on the basis of feather structure (longer and more pointed outer primaries). The attached bones (radius and humerus) were also visibly more robust than the equivalent Raven wing-bones in the sample (Plate 30). On wing-length against the Raven wings, the Black Falcon was probably male. The breeding Peregrine Falcons in the ACT high country took ravens and other large, potentially dangerous prey apparently because their usually smaller avian prey species were scarce, at least in the airspace above forest cover at that altitude, and the female Peregrine Falcons were probably doing much hunting to help supply their broods (Olsen et al. 2004). We speculate that a vagrant Black Falcon (which can be raven-like in non-hunting direct flight), traversing high over the forest around Corin Dam, was mistaken for a raven and so attacked as prey by a female Peregrine Falcon. In flight, female Peregrine Falcons can outmanoeuvre and defeat would-be piratical Black Falcons (Hollands 1984), so it may be a small step to fatally strike a male Black Falcon. Conversely, there is a record of a male Peregrine Falcon being taken by a Black Falcon of unknown sex (probably female) (Hollands 1984). AUSTRALIAN 134 OLSEN, ROSE & BOLES Field Ornithology

Black Falcon wing (right) and Australian Raven wing (left) among Peregrine Falcon prey remains, Corin Dam, ACT, December 2006 Plate 30 Photo: Jerry Olsen

This pair of Peregrine Falcons also took a Kestrel in 2006 (Table 1) and a Long-tailed Jaeger Stercorarius longicaudus in 1994, the first record of this pelagic seabird in the ACT (Boles et al. 2004). As the area around this Peregrine Falcon nest is heavily forested, most prey is caught over the tree-canopy, or over the dam water (JO pers. obs). The findings for 2006 are consistent with the findings for earlier years at this site (Olsen et al. 2004), with respect to large, dangerous prey taken at that altitude over that habitat type. We thank Leah Tsang (Australian Museum) and Stephen Debus (Zoology, University of New England) for helping to resurrect this note, and for editing it. Thanks go also to members of the ACT Parks & Conservation Service, especially Murray Evans, Brett McNamara, Keith Smith and Michael Maconachie. ABR gratefully acknowledges the facilities of the Australian Museum. VOL. 28 (3) SEPTEMBER 2011 Black Falcon Taken by Peregrine Falcon 135

Table 1 Prey taken by a breeding pair of Peregrine Falcons at Corin Dam, ACT, in 2006 from collections of prey remains at the cliff eyrie in November (nestlings) and December (fledglings). Prey species Nov. Dec. Total

Rock Dove Columba livia 1 1 2 Ocyphaps lophotes 1 1 White-throated Needletail Hirundapus caudacutus 1 1 Nankeen Kestrel Falco cenchroides 1 1 Black Falcon Falco subniger 1 1 Gang-gang Callocephalon fimbriatum 2 2 Eolophus roseicapillus 1 1 2 Crimson Rosella Platycercus elegans 1 1 2 Fan-tailed Cuckoo Cacomantis flabelliformis 1 1 Sacred Kingfisher Todiramphus sanctus 1 1 Anthochaera carunculata 1 1 White-browed Woodswallow Artamus superciliosus 1 1 Pied Butcherbird Cracticus nigrogularis 1 1 Cracticus tibicen 2 2 Pied Currawong Strepera graculina 1 1 Australian Raven Corvus coronoides 1 3 4 Magpie-lark Grallina cyanoleuca 1 1 Sturnus vulgaris 1 2 3 Anthus novaeseelandiae 1 1 Unidentified 1 1 Total 7 23 30

References Boles, W.E., Rose, A.B. & Olsen, J. (2004), ‘A record of the Long-tailed Jaeger Stercorarius longicaudus in the Australian Capital Territory’, Australian Field Ornithology 21, 158–162. Debus, S.J.S. & Olsen, J. (2011), ‘Some aspects of the biology of the Black Falcon Falco subniger’, Corella 35, 29–36. Hollands, D. (1984), Eagles, and Falcons of Australia, Nelson, Melbourne. Marchant, S. & Higgins, P.J. (Eds) (1993), Handbook of Australian, New Zealand and Antarctic , vol. 2, Oxford University Press, Melbourne. Olsen, J., Debus, S.J.S., Rose, A.B. & Hayes, G. (2004), ‘Breeding success, cliff characteristics and diet of Peregrine Falcons at high altitude in the Australian Capital Territory’, Corella 28, 33–37. Schoenjahn, J. (2011), ‘Morphometric data from recent specimens and live individuals of the Falco hypoleucos’, Corella 35, 16–22.

Revised 13 August 2011 