Plumbeous Hawk Cryptoleucopteryx plumbea Scientific name definitions

The Plumbeous Hawk is one of the most poorly known members of the Neotropical genus Leucopternis. This species is distributed along the west slope of the northern Andes in the Choco biogeographic region in northwestern Colombia and western Ecuador, where it is resident in humid lowland forest and foothills up to 800 m. The Plumbeous Hawk feeds on small vertebrates, which it hunts in the forest interior with a perch-and-wait strategy. Though it is the only completely slate-colored Leucopternis in its range, it might be confused with the Crane Hawk (Geranospiza caerulescens), but note the Crane Hawk's larger size, longer tarsi, conspicuously banded tail and more slender structure.

33–37 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); no data on body mass; wingspan 71–79 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Adult is leaden grey overall ; wings black, single conspicuous white median band through black tail; underwing-coverts white; thighs finely barred with white; iris reddish-orange to red; cere, lores and legs orange. Differs from closely related B. schistaceus in smaller size (wing length 219–248 mm vs 263–304 mm in schistaceus (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ) ), colours of bare parts and underwing-coverts, lack of white terminal band on tail. Sexes similar, female on average very slightly larger than male. Immature has more conspicuous barring on thighs, faint grey mottling on belly, brownish eyes.

This species and Buteogallus schistaceus previously placed in Leucopternis, and thought to be closely related or even conspecific, but genetic data indicate that they are not even congeneric (2 Amaral, F. S. R., M. J. Miller, L. F. Silveira, E. Bermingham, and A. Wajntal (2006). Polyphyly of the hawk genera Leucopternis and Buteogallus (Aves, Accipitridae): multiple habitat shifts during the Neotropical buteonine diversification. BMC Evolutionary Biology 6(10):1–21. Close , 3 Amaral, F.S.R., Sheldon, F.H., Gamauf, A., Haring, E., Riesing, M., Silveira, L.F. and Wajntal, A. (2009). Patterns and processes of diversification in a widespread and ecologically diverse avian group, the buteonine hawks (Aves, Accipitridae). Molecular Phylogenetics and Evolution. 53(3): 703–715. Close ). Monotypic.

E Panama through W Colombia and NW Ecuador to extreme NW Peru (Tumbes).

Tropical rainforest, largely in closed-canopy interior of lowland and foothill forests; has also been recorded in degraded forest. Reported from sea-level to 1400 m, but mostly from 200–800 m (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ).

Little known; frogs, crabs, fish and water snakes have been reported. Hunts along banks of rivers and lakes; probably captures prey mainly by sit-and-wait hunting. Not known to soar.

Most common vocalization is a loud, overslurred drawn-out whistle wheeeeeuuu, with a melancholous tone quality. When excited, also utters a trilled call "weedidididi".

VULNERABLE. CITES II. Range presently restricted to area less than 2000 km long and 20–100 km wide (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Rare in E Panama (4 Ridgely, R. S., and J. A. Gwynne (1989). A Guide to the Birds of Panama with Costa Rica, Nicaragua, and Honduras. Second edition. Princeton University Press, Princeton, NJ, USA. Close ) (apparently extinct in much of W Panama, except for a sighting from Veraguas, Santa Fe in 1995); rare in W Colombia (5 Hilty, S. L., and W. L. Brown (1986). A Guide to the Birds of Colombia. Princeton University Press, Princeton, NJ, USA. Close ) where recorded from several scattered localities S from S Córdoba, especially in Nariño; rare to locally uncommon in NW Ecuador (6 Ridgely, R. S., and P. J. Greenfield (2001). The Birds of Ecuador. Volumes 1–2. Comstock Publishing Associates, Ithaca, New York, USA. Close ). No real estimates of global population, but unlikely to exceed lower end of four-figure range (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Across most of this species’ range deforestation, primarily for agricultural expansion and timber harvest, is widespread and apparently accelerating in rate; one may presume that this would have adverse effects on this forest-obligate species, but it is an inconspicuous hawk and may well be under-recorded where it occurs. Uplisted to Vulnerable in 2014 on suspicion of rapid population decline caused by ongoing habitat loss and degradation. Field study and assessment of its capacity for persisting in degraded and/or fragmented forest would be useful, as would a reliable estimate of its global numbers, population trends and limiting factors. Extension of protected-areas network may ultimately be essential to the survival of this and many other species.