Spot-winged Falconet Spiziapteryx circumcincta Scientific name definitions

The Spot-winged Falconet is the only member of its genus and is endemic to the chaco savannas, woodland and scrub of Bolivia and central Argentina. It is a small raptor, about the same size as the American Kestrel (Falco sparverius), but with a very different plumage. The falconet is grayish brown above and white below with dark streaking throughout, and a white rump,; its name comes from the white spots on the flight feathers and wing coverts. It feeds primarily on insects, especially flying ones such as dragonflies, damselflies and cicadas, but will also take lizards and small birds. The Spot-winged Falconet is occasionally tolerated at the communal nests of Monk Parakeets which it often uses for roosting. Indeed, the falconet has been observed roosting in active Monk Parakeets nests with the parakeets entering the chamber after the falconet and spending the night with them.

25–31 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); 149–249 g (n = 22, sexes combined), means of 157·8 g and 188 g for four males and four females, respectively (2 Bechard, M.J, Sarasola, J.H. and Helbig, A.J. (2004). Morphometric measures of male and female Spot-winged Falconets Spiziapteryx circumcinctus sexed using PCR amplification methods. Pp. 451–458 in: Chancellor, R.D. & Meyburg, B.U. eds. (23733734). Raptors Worldwide. Proceedings of the VI World Conference on Birds of Prey and Owls, Budapest, Hungary. WWGBP & MME/BirdLife Hungary, Berlin & Budapest. Close ); wingspan 47–58 cm (2 Bechard, M.J, Sarasola, J.H. and Helbig, A.J. (2004). Morphometric measures of male and female Spot-winged Falconets Spiziapteryx circumcinctus sexed using PCR amplification methods. Pp. 451–458 in: Chancellor, R.D. & Meyburg, B.U. eds. (23733734). Raptors Worldwide. Proceedings of the VI World Conference on Birds of Prey and Owls, Budapest, Hungary. WWGBP & MME/BirdLife Hungary, Berlin & Budapest. Close ). Diminutive; stocky, with shortish wings but relatively long graduated tail (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Flight appears whirring with much flapping, followed by short glides (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Back, head and wings greyish-brown; pale streak above and behind eye, black ear-coverts and narrow black moustachial streak; shoulders spotted white, rump white; throat and lower belly white; breast, sides and upper belly greyish , narrowly streaked brown; central rectrices dark, rest of tail barred white, with white tip; conspicuous white spots on wing , white underwing-coverts. Iris pale yellow , cere and lores rich yellow (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), and feet and legs cream to yellow (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Female similar to male but averages c. 8% larger (2 Bechard, M.J, Sarasola, J.H. and Helbig, A.J. (2004). Morphometric measures of male and female Spot-winged Falconets Spiziapteryx circumcinctus sexed using PCR amplification methods. Pp. 451–458 in: Chancellor, R.D. & Meyburg, B.U. eds. (23733734). Raptors Worldwide. Proceedings of the VI World Conference on Birds of Prey and Owls, Budapest, Hungary. WWGBP & MME/BirdLife Hungary, Berlin & Budapest. Close ). Unlike other falconids, no distinct immature plumage.

E Bolivia (Santa Cruz) through Paraguay to N & C Argentina (S to E Río Negro) and W Uruguay (3 Azpiroz, A.B. (2003). Aves del Uruguay. Lista e Introducción a su Biología y Conservación. Aves Uruguay-GUPECA, Montevideo. In Spanish. Close ).

Mainly lowland savanna and semi-arid woodland with scrub; common characteristics of all habitats are scrub with scattered trees such as mesquite (Prosopis nigra) and some bare ground (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Chaco in Bolivia; semi-open Chaco forest and monte desert in Argentina (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Elevational range sea-level to c. 750 m, but probably mainly from 100–500 m (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Probably sedentary. Of 22 birds trapped in SC Argentina, three re-trapped within a year after ringing, all within 500 m of the original capture location (2 Bechard, M.J, Sarasola, J.H. and Helbig, A.J. (2004). Morphometric measures of male and female Spot-winged Falconets Spiziapteryx circumcinctus sexed using PCR amplification methods. Pp. 451–458 in: Chancellor, R.D. & Meyburg, B.U. eds. (23733734). Raptors Worldwide. Proceedings of the VI World Conference on Birds of Prey and Owls, Budapest, Hungary. WWGBP & MME/BirdLife Hungary, Berlin & Budapest. Close ). However, Paraguayan record might have involved a wandering individual (or genuine range extension) (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); species also has recently been recorded in Santa Cruz province, S Argentina, 1000 km S of known range (4 Bornschein, M.R. (1996). Extralimital record of the Spot-winged Falconet Spiziapteryx circumcinctus. Bull. Brit. Orn. Club. 116(3): 197–198. Close ).

Feeds on insects (Orthoptera, cicadas, beetles and probably others), lizards, small mammals (e.g. cavies Microcavia) and birds, including Rufous Hornero (Furnarius rufus) and Barred Antshrike (Thamnophilus doliatus) (5 Kratter, A.W., Sillett, T.S., Chesser, R.T., O’Neill, J.P., Parker, T.A. and Castillo, A. (1993). Avifauna of a Chaco locality in Bolivia. Wilson Bull.. 105(1): 114–141. Close , 1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close , 2 Bechard, M.J, Sarasola, J.H. and Helbig, A.J. (2004). Morphometric measures of male and female Spot-winged Falconets Spiziapteryx circumcinctus sexed using PCR amplification methods. Pp. 451–458 in: Chancellor, R.D. & Meyburg, B.U. eds. (23733734). Raptors Worldwide. Proceedings of the VI World Conference on Birds of Prey and Owls, Budapest, Hungary. WWGBP & MME/BirdLife Hungary, Berlin & Budapest. Close ). Bird prey also includes adult and young Monk Parakeets (Myiopsitta monachus); present species roosts in communal nests of these parakeets in winter, and nests in them in summer; actually observed roosting in active Monk Parakeet nests, with parakeets entering chamber after the falconets, and spending the night with them. Little information on hunting techniques, but known to still-hunt from perch (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Gives series of nasal clucking notes that fall in pitch when disturbed at nest; also a loud, guttural "kronk, kronk, kronk..."  (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Very little information available. No aerial displays known (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Laying in Nov–Dec in Argentina, although birds in breeding condition from there also taken in Jul, Aug and Oct (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); suspected to be double-brooded (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Nest in woven, closed nests of other species, e.g. cachalotes (Furnariidae), probably Firewood-gatherer (Anumbius annumbi) (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ) and sometimes active Monk Parakeet colonies; near Córdoba (NC Argentina), 15 out of 70 Monk Parakeet nests also had a nesting pair of falconets. For nesting, Monk Parakeet nest entrances are enlarged to 20 cm high × 30 cm wide, and nest chamber enlarged into roughly spherical cavity c. 30 cm wide, but no lining is added (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Not known to use artificial nest boxes (6 Liébana, M.S., Sarasola, J.H. and Santillán, M.Á. (2013). Nest-box occupancy by Neotropical raptors in a native forest of central Argentina. Journal of Raptor Research. 47(2): 208-213. Close ). Clutch size 2–4 eggs; fledging probably c. 33 days.

Not globally threatened (Least Concern). CITES II. Status virtually unknown, although considered locally common in Córdoba, Argentina (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), and reasonably numerous at a locality in Santa Cruz, Bolivia (5 Kratter, A.W., Sillett, T.S., Chesser, R.T., O’Neill, J.P., Parker, T.A. and Castillo, A. (1993). Avifauna of a Chaco locality in Bolivia. Wilson Bull.. 105(1): 114–141. Close ); populations presumed to be stable in absence of evidence to the contrary. Preferred habitat is not among those most seriously devastated in the region. Single record from Paraguay.