Crane Hawk, Geranospiza caerulescens

Crane Hawk, Geranospiza caerulescens vivens. Photographs taken within a residential community in Alamos, Sonora, February and March 2018. Photographs and identification courtesy of David F Smith, Alamos, Sonora.

Background and Identification

The Crane Hawk, Geranospiza caerulescens vivens, is a one of six subspecies of Crane Hawk, three of which reside in Mexico, and is a member of the Accipitridae Family of Eagles, Hawks and Kites, and the sole global species of the Geranospiza Genus. They normally do not soar and are usually seen flying low overhead or perched in a tree. They consume arthropods, nestling birds, frogs, fruits, lizards, mollusks, rodents and snakes. The Crane Hawk is poorly studied and very little about their behavioral patterns has been documented. They are known in Mexico as Azor Zancón.

The Crane Hawk is large in stature, with an average length of 38 cm (15 inches) to 54 cm (21 inches). Females tend to be slightly larger than males, with an average mass of 273 g (9.6 oz) to 430 g (15 oz). Males have an average mass of 225 g (8 oz) to 358 g (13 oz). They have a uniform slate-gray to slate-black plumage with obscure barring on the belly, thighs, and crissum, a distinctive white crescent on the undersides of their primaries, and a long, slender, black-and-white banded, white-tipped tail. These bands on the tail are one of the best identifiers of the Crane Hawk. They have long double-jointed orange-red legs, their iris is crimson, and their cere is lead color. The cere is the fleshy area at the base of the bird’s beak where the nostrils sit. The females are similar in appearance to the males but slightly larger.

Habitat and Geographical Range

The Crane Hawk is found in a wide variety of habitats including lowland semi-deciduous forests to rainforests, mangroves, wooded savannas, or grasslands, often near ponds and marshes from sea-level to elevations up to 750 m (1,600 feet). They are non-migratory with a relatively small home range.

Geographically, Crane Hawks are found primarily in tropical and subtropical regions of Central and South America, from northern Argentina to Mexico. The Crane Hawk has a limited distribution in Mexico, found in all coastal regions of both the Atlantic and Pacific Slopes. The livens subspecies is limited to northwestern Mexico in Sonora and northern Sinaloa.

Common Misidentifications

The Crane Hawk can sometimes be confused with other similarly sized raptors, such as the Gray Hawk, Buteo plagiatus, or the Roadside Hawk, Rupornis magnirostris. However, the Crane Hawk’s long legs and unique hunting behavior set it apart. This species uses double-jointed legs to access prey. In flight, its slate-gray color and banded tail can resemble other hawks, but its overall build and foraging behavior are distinctive.

Conservation Status

From a conservation perspective the Crane Hawk is currently considered to be of Least Concern with stable, widely-distributed populations. However, they are generally uncommon and within Mexico, their populations are believed to be in decline which has been attributed to deforestation. Their total populations are estimated to be between 500,000 and 5 million individuals.