Slaty-backed Forest-Falcon Micrastur mirandollei Scientific name definitions

The Slaty-backed Forest-Falcon is a bicolored raptor of lowland Neotropical forests. It occurs from Panama south through the Amazon basin, and also in eastern Brazil. Adults are gray above and white below, with a long, rounded tail with three white bands. It differs from raptors with similar plumage primarily in structure and size. The typical call is longer than other forest-falcons, usually with 7-10 notes repeated in a trogon-like series. The Slaty-backed Forest-Falcon generally hunts higher in the forest than other forest-falcons, preying on birds in the canopy or mid-story. There is no information on the nest or breeding behavior of this species.

40–45 cm; male c. 420 g, female c. 500–556 g (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); wingspan 65–71 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Slate-grey above, darker on crown and tail, but paler on cheeks, with white to cream-coloured underparts  , unmarked but for a few, scattered dark shaft streaks (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); tail short­er than in other Micrastur species, with three often indistinct pale bands and narrow white tip; underparts  , including wing linings, white or tinged buff, with narrowly dark-barred remiges and broad blackish trailing edge (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Very similar to immature Accipiter bicolor and some immatures of M. ruficollis, and also to smaller Leucopternis semiplumbeus (fewer tailbands) and Accipiter poliogaster; differs in structure, notably in longer legs and more extensive bare facial skin, and in fine details of plumage. Distinguished from recently described M. mintoni by bare-parts coloration, lack of barring on underparts and tail pattern, among other features. M. semitorquatus is larger and longer-tailed, with clear nuchal collar (although many views of Micrastur) are brief, while adult Accipiter poliogaster has less graduated tail, relatively shorter legs, comparatively more hooded appearance and broader tailbands, among other features (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Female almost certainly heavier, but no other differences in size noted (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Iris dark brown to yellowish brown (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), cere greenish yellow  (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), legs and feet bright yellow  . Juvenile dark brownish grey above; off-white or dusky to yellowish buff below (especially breast) (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), with feathers edged fuscous brown, giving scaly effect.

Costa Rica, Panama and Colombia S down W slope of Andes to NW Ecuador (Esmeraldas), and E through Amazonia to the Guianas and NC Brazil (NE Pará) and S to C Bolivia; also E Brazil (Espírito Santo).

Lowland tropical rainforest, often in fairly undisturbed parts and frequently associated with streams or rivers (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ), but also in tall secondary growth and sometimes rather open areas (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). In areas of overlap with M. semitorquatus, present species occupies canopy or upper levels of forest, but elsewhere typically found in understorey (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Recorded from sea-level to at least 500 m, but mainly below 200 m (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Presumably sedentary, although juveniles might be expected to wander to some extent (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Very little information available. Feeds on birds, e.g. Dusky-faced Tanager (Mitrospingus cassinii), lizards and snakes (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Hunts in middle to lower levels of forest, sometimes even taking prey on ground (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Reportedly perches low in understorey, uttering calls that elicit mobbing response from small birds; once flock of birds is attracted, forest-falcon moves stealthily, sometimes on foot, to another perch, where it resumes calling; birds caught as they move about trying to relocate the calling forest-falcon; these unusual observations require corroboration. May also follow army ant swarms, presumably to pick off birds feeding on the fleeing insects.

Mainly heard around dusk or dawn (sometimes well before first light): chanting series of 8–13 nasal "kiiih" or "kaaah" notes, the initial 3–4 becoming successively longer and lower-pitched, with the next 4–6 gradually becoming higher-pitched, whereas the last 2–3 notes are on even pitch, while volume increases throughout the series (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). High-pitched, ventriloquial "eek-eek-eek..." given for 8–10 seconds at c. 20-second intervals, which provokes mobbing by forest passerines, which find the source difficult to locate (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

No information available. Presumably nests in tree cavities, as do congeners.

Not globally threatened (Least Concern). CITES II. Status very poorly known, perhaps in part because so easily confused with other species. Widely distributed, but everywhere rare and perhaps patchily present, e.g. first records for Rondônia, SW Brazil, only recent (3 Olmos, F., L. F. Silveira, and G. A. Benedicto (2011). A contribution to the ornithology of Rondônia, southwest of the Brazilian Amazon. Revista Brasileira de Ornitologia 19(2):200–229. Close ). One of rarest forest raptors in French Guiana, with estimated minimum average density of only four individuals/10,000 ha of forest.