[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Geranospiza caerulescens | [authority] Vieillot, 1817 | [UK] Crane Hawk | [FR] Buse echasse | [DE] Sperberweihe | [ES] Azor Zancon | [NL] Langpootkiekendief
Subspecies
Monotypic species
Genus
Members of the genus Geranospiza are medium-sized, slender, lightly built hawks. The wings are short, broad, and rounded with broad secondaries. The tail and legs are long. The legs are terminated by short, especially the outer one. The joint at the ‘heel’ is flexible in either direction; this facilitates reaching into crevices after prey. Plumage is generally soft, lax and blended. Immatures are not conspicuously different from adults. It is very possible that this genus is related to Polyboroides of Africa, although this may be just a very close resemblance, and this genus may be more closely related to American genera as Leucopternis. The genus contains only one species, in the American tropics from Mexico to Argentina.
Physical charateristics
Geranospiza caerulescens nigra. Mexico (except north-west), south to the Panama Canal Zone. The adult is slaty black with a glaucous cast. The tail has a white tip and two prominent white bars. The belly, thighs and wing linings have indistinct white tips. The inner vane of each primary has a white spot, forming a bar when the wing is spread. The eyes are crimson; the bill black; the lores and cere are deep grey; the legs orange-red.
Geranospiza caerulescens livens of North-western Mexico is larger and paler; deep grey rather than greyish black.
Geranospiza caerulescens baizarensis of the Pacific slope from eastern Panama to north-western Peru is similar to G. c. livens, but smaller. The young are more extensively marked with buffy white below, and the under-tail coverts are a rich buff.
Geranospiza caerulescens caerulescens of eastern Colombia and Ecuador, Venezuela, Guiana, and Brazil as far south as the Amazon Valley is paler than any of the preceding races; with or without some whitish barring on belly and thighs. The young are very extensively mottled below with yellowish buff.
Geranospiza caerulescens gracilis resides in North-eastern Brazil, as far south as Bahai. It is uniformly and sharply barred below grey and white (the barring is sometimes absent from the throat and chest). The wing coverts, upper and lower, are also barred to some extent. There is less black, and more tawny on the tail. The young are buffer below. Geranospiza caerulescens fiexipes of Southern Brazil, Paraguay, northern Argentina and Bolivia is larger and paler than G. c. gracilis.
Geranospiza caerulescens livens of North-western Mexico is larger and paler; deep grey rather than greyish black.
Geranospiza caerulescens baizarensis of the Pacific slope from eastern Panama to north-western Peru is similar to G. c. livens, but smaller. The young are more extensively marked with buffy white below, and the under-tail coverts are a rich buff.
Geranospiza caerulescens caerulescens of eastern Colombia and Ecuador, Venezuela, Guiana, and Brazil as far south as the Amazon Valley is paler than any of the preceding races; with or without some whitish barring on belly and thighs. The young are very extensively mottled below with yellowish buff.
Geranospiza caerulescens gracilis resides in North-eastern Brazil, as far south as Bahai. It is uniformly and sharply barred below grey and white (the barring is sometimes absent from the throat and chest). The wing coverts, upper and lower, are also barred to some extent. There is less black, and more tawny on the tail. The young are buffer below. Geranospiza caerulescens fiexipes of Southern Brazil, Paraguay, northern Argentina and Bolivia is larger and paler than G. c. gracilis.
Listen to the sound of Crane Hawk
[audio:https://planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Crane Hawk.mp3]
Copyright remark: Most sounds derived from xeno-canto
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Range
Latin America : Mexico to Uruguay. N Mexico (Sinaloa and Tamaulipas) S to zone of Panama Canal. Panama E of canal zone on Pacific slope to W Colombia, W Ecuador and NW Peru (Lambayeque).
Habitat
This is a bird of tropical lowlands, preferring the vicinity of water, even if only a brush lined creek reduced to scattered stagnant pools.
It is perhaps at its most common in scrub or deciduous tropical woodland with small streams or pools, like in the ranch-lands of north-western Costa Rica, the dry forest of northern Venezuela, or the chaco.
It is perhaps at its most common in scrub or deciduous tropical woodland with small streams or pools, like in the ranch-lands of north-western Costa Rica, the dry forest of northern Venezuela, or the chaco.
Reproduction
In its display it flaps and soars in tight circles, then climbs abruptly and immediately drops sharply. It also will sit in the top of a tall tree, flopping its tail to keep its balance and calling.
In Mexico the nests are built in cypresses in creek bottoms, often with sub-arid vegetation nearby, about 50 feet up in very tall cypresses, either next to the trunk, or far out on a limb. Nests have also been seen in Surinam some 35 feet up in a shady tree among coffee. Nests are small open cups of small twigs and vine stalks; lined with grass, weed stalks, small twigs, usually lined with some green leaves. Eggs are plain white; like a harrier’s.
In Mexico the nests are built in cypresses in creek bottoms, often with sub-arid vegetation nearby, about 50 feet up in very tall cypresses, either next to the trunk, or far out on a limb. Nests have also been seen in Surinam some 35 feet up in a shady tree among coffee. Nests are small open cups of small twigs and vine stalks; lined with grass, weed stalks, small twigs, usually lined with some green leaves. Eggs are plain white; like a harrier’s.
Feeding habits
Lizards, snakes, large insects, spiders and tree frogs predominate. Small birds, such as parrots, are sometimes pulled from the nest.
Video Crane Hawk
httpv://www.youtube.com/watch?v=RN4MP4wNpLI
copyright: K. Blomerley
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The Crane Hawk can be found in the tropical lowlands from Mexico to eastern Bolivia, northern Argentina and Paraguay.
The Crane Hawk can be found in the tropical lowlands from Mexico to eastern Bolivia, northern Argentina and Paraguay.
Migration
Very little data available, thought to be sedentary.
Distribution map
Literature
Title Nesting of the Crane Hawk in Surinam.
Author(s): F. HAVERSCHMIDT
Abstract: Crane Hawk (Gevanosfiza caerulescens) in_ habits t..[more]..
Source: The Condor, 66(4)