Brown Falcon Falco berigora Scientific name definitions

41–51 cm; male 316–590 g, female 430–860 g (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); wingspan 88–115 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Medium- to large-sized, round-shouldered falcon with long legs (unique for the genus) and relatively small feet (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Extremely variable in colour, ranging from pale almost like F. cenchroides but with rufous thighs , to dark like <em>F. subniger</em> but with barred underwings  and tail . Distinguished from F. subniger by long legs. In adult, irides dark brown (rarely hazel); cere, orbital rings and feet pale grey to whitish or dull yellow (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Juvenile brown with buff forehead, throat and vent; cere, orbital rings and feet bluish-grey. Regional variation in size and colour: resident tropical race small and rufous or dark; SW birds small and rufous.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Found in a wide variety of habitats, being consistently absent only from dense stands of rainforest and eucalyptus. Frequents open woodland, savanna, grassland, farmland and deserts from sea-level to 2000 m in Australia, rarely to 3000 m in New Guinea (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Typically nests in old stick nests in trees.

Adults generally sedentary, or with local movements to winter territories. Juveniles dispersive or partly migratory within Australia; S birds winter to N, some reaching tropical Australia and New Guinea. Some irruptive movements to sites of abundant prey and possibly in response to drought. One ringing recovery of 2047 km within Australia (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Mammals, birds, reptiles (commonly snakes), amphibians, arthropods and carrion (2 Hatton, F. (2013). Brown Goshawk and Brown Falcon scavenging. Boobook. 31(2): 41. Close ); rarely fish and freshwater molluscs (the latter perhaps pirated; but see below) (3 van Tets, G.F. (1994). Do cormorants eat freshwater mussels? If not what does? Emu. 94(2): 127-128. Close ). Diet varies seasonally. Forages mostly by still-hunting from exposed perch ; also by quartering and hovering , by low fast flight or by soaring. Seizes prey on ground by glide, dive or direct flying attack that may become short chase. Pursues insects on foot; robs other raptors (4 Schoenjahn, J. (2012). Brown Falcon kleptoparasitising Black-shouldered Kite. Boobook. 30(1): 19. Close , 5 Richards, D. (2013). Brown Falcon stealing from Eastern Osprey. Boobook. 31(1): 17. Close ). Follows fires, livestock and other animals and farm machinery for flushed prey; pairs sometimes hunt co-operatively. Diet of breeding birds near Canberra (n = 307 prey items) comprised of 55% insects, 1% crustaceans, 6% molluscs, 7% reptiles, 14% birds, 17% mammals; unusual prey included Helix snails, Cherax crayfish, the freshwater molluscs  Corbicula australis and Glyptophysa gibbosa, and a Southern Boobook (Ninox boobook) (6 McDonald, P.G., Olsen J. and Rose, A.B. (2012). The diet of breeding Brown Falcons (Falco berigora) in the Canberra region, Australia, with comparisons to other regions. Journal of Raptor Research. 46(4): 394-400. Close ).

Quite vocal, including away from the nesting area. Main call is a repeated raucous screaming “crreeah”  (not unlike a caracara). Also gives a variety of quieter clucks and croaks in contact. Cackles when flushing prey from cover (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Apr–Sept in N, Aug–Oct in S. Solitary. Uses old stick nest of other raptor or Corvus in tree; rarely on tree fern, shrub, vines, artificial structure, cliff or termitarium; 4–30 m above ground. Usually 2–3 eggs (1–5); size highly variable, 44·3–61·3 mm × 29·6–41·8 mm (7 Olsen, P. D., and T. G. Marples (1993). Geographic variation in egg size, clutch size and date of laying of Australian raptors (Falconiformes and Strigiformes). Emu 93:167–179. Close ); incubation 31–36 days; chicks have pale rufous first down, grey second down; fledging 36–42 days; post-fledging dependence 2–6 weeks. Success variously measured as 69% fledging success (of eggs laid), 1·77 young fledged per nest, and 2·39 per successful nest; 2·2 young raised per clutch laid, 2·3–2·4 per successful nest, and 1·7 young per territorial pair. Pairs defend nesting territories year-round (8 McDonald, P.G. (2004). The breeding ecology and behaviour of a colour-marked population of Brown Falcons (Falco berigora). Emu. 104(1): 1-6. Close ). In 3-year study near Melbourne, Australia, 44–49 pairs fledged an average of 1·0–1·8 young per breeding attempt and 1·9–2·5 young per successful nest; overall nesting success ranged from 29·5–64·4% (9 McDonald, P.G., Olsen P.D. and Baker-Gabb, D.J. (2003). Territory fidelity, reproductive success and prey choice in the Brown Falcon, Falco berigora: a flexible bet-hedger? Australian Journal of Zoology 51(4): 399-414. Close ); nesting success, productivity and adult survival were lowest in years when severe weather events occurred most frequently (10 McDonald, P.G., Olsen P.D. and Cockburn, A. (2004). Weather dictates reproductive success and survival in the Australian Brown Falcon Falco berigora. Journal of Animal Ecology. 73(4): 683-692. Close ). Age at first breeding three years for males, two years for females. Oldest ringed bird 11 years; longevity 16 years in captivity  .

Not globally threatened (Least Concern). CITES II. Common and widespread, especially in Australia, where one of the two most common falconids (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); generally uncommon in New Guinea, however (11 Pratt, T. K., and B. M. Beehler (2015) Birds of New Guinea. Second edition. Princeton University Press, Princeton, NJ, USA. Close ). Global population perhaps as high as 225,000 breeding pairs (12 Cade, T. J. (1982). The Falcons of the World. Collins, London, UK and Cornell University Press, Ithaca, NY, USA. Close , 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Benefits from most agricultural activities, but sometimes shot or trapped. Eggshell thickness not significantly reduced by DDT in Australia.