Black-and-white Hawk-Eagle - Distribution and Ecology

Distribution and Ecology

This species occurs from Oaxaca to Veracruz in southern Mexico southwards throughout Central America, with the exception of most of El Salvador and the Pacific coast of Nicaragua. In South America, it occurs on the Pacific side of the Andes south to Ecuador. The bulk of its range extends along the Caribbean coast from northern Colombia and Venezuela to the Guianas, and south through eastern Brazil, Paraguay and Uruguay to NE Argentina, and from there westwards again to Beni and Santa Cruz in NE Bolivia. A Black-and-white Hawk-Eagle population is also found in the Loreto Region of NE Peru; it is not known in how far this is isolated from the rest of the bird's range. The species is absent from western Amazonia, and it is not common in the lands to the east (e.g. in Minas Gerais).

Its natural habitats are lowland forests of any type, though very dense and humid as well as savanna-like semiarid habitat are not preferred. Habitat fragmentation is not very well tolerated; though the species prefers a diverse habitat of mixed forest and shrubland, it requires large stands of closed-canopy forest to thrive. Its range does not extend very far into the uplands, but one individual was sighted at an altitude of about 4,000 ft (c.1,200 m) ASL in the Buena Vista Nature Reserve in Colombia's Sierra Nevada de Santa Marta.

The food of this carnivore consists of mammals, toads, squamates and in particular a wide variety of birds. Among the latter, it is known to prefer tree-living species, such as oropendolas, aracaris, tanagers and cotingas. But ground- and waterbirds like tinamous, chachalacas, cormorants and the highly threatened Brazilian Merganser (Mergus octosetaceus) have also been recorded as its prey. The Black-and-white Hawk-Eagle has been known to attack small monkeys, though it is not clear with which intent. For as it seems, it has not been recorded to actually kill and eat a monkey.

Its preferred hunting technique is to soar high until it has spotted suitable prey, and then dive down on it, usually right into the forest canopy, but it has also been observed to catch a White Woodpecker (Melanerpes candidus) that had been mobbing it in mid-air, after launching itself from its perch. It likes to hunt along ridges and forest edges where it can access the canopy-level from an oblique direction rather than just from directly above, and where ground-living prey is also more accessible.

It nests in the forest canopy, building a stick nest high up in exposed trees on ridges and similar locations, from where good hunting grounds can be watched. Detailed observations on its nesting habits are nearly non-existent however. In Panama, birds started to construct a nest in September, during a dry spell in the rainy season. But the main nesting season may start before the onset of the rainy season as the nesting attempt was abandoned when heavy rains recommenced. The scant other data agrees with this, and at least in Central America the nesting season seems to run from March to June or so.

There is a general lack of information on the Black-and-white Hawk-Eagle's movements and population status. Each bird seems to require a hunting territory of about 3,500 acres (1,400 hectars) at least. While the variety of habitat types in which it is found suggests that it is not particularly susceptible to changes in land use, it is apparently still a rare and local species almost anywhere in its range. The IUCN until 2000 classified it as a Near Threatened species due to the uncertainties surrounding its status, but as no evidence of a marked decline has been found and as the bird is found across a wide range, it was downlisted to a Species of Least Concern.