Crested Hawk-Eagle

The Crested Hawk-Eagle is a largish but slender eagle. They fall near the middle of sizes among the currently accepted species in the genus Nisaetus. As in most birds of prey, females are larger than males with an average overall size difference of 7% but this can individually range to an 18-22% difference, with island races apparently thought to be less dimorphic on average.

Adult changeable hawk-eagles are typically dark brown above and boldly streaked below with a strong bill, a variably sized, often floppy crest or no crest, rather short wings, a quite long, thinly-barred tail and long feathered legs. This species tends to perch “bolt” upright, and may perch in various places from somewhat secluded spots to also quite open area as well.

Distribution and habitat

The extensive range of the changeable hawk-eagle includes much of the Indian subcontinent and southeast Asia. Their distribution includes nations and areas such as Sri Lanka, Himalayan foothills, southern Nepal and Bhutan east through Myanmar, Burma, western Laos, southern Vietnam, Cambodia, Thailand and peninsular Malaysia. In India, they may found almost continuously from the peninsular tip north to Rajasthan, Uttar Pradesh, Bihar and Odisha. Its island distribution includes the Andamans, Sumatra, Java, Borneo and the western and southern Philippines. Like most tropical raptors, the changeable hawk-eagle is largely residential, but stragglers from peninsular India have roamed to northeastern Burma and southeastern Thailand and some records in the Lesser Sunda Islands may be from vagrants from Java.

The species may live in savannah woodland, cultivation with trees, timbered watercourses, tea plantations, forest villages and even suburban edge.

Voice

The changeable hawk-eagle is often largely silent but in breeding season it may readily call, both from their perch or on the wing. Like many diurnal raptors, their calls are a form of high-pitched scream. The shrill ringing and loud call of the changeable hawk-eagle is various described in pattern of yeep-yip-yip-yip, rising kwip-kwip-kwip-kwee-ah and penetrating klee-leeuw (for birds from the Sunda islands). Ascending kri-kri-kri-kree-ah and kreeee-krit with much stress on the elongated first syllable are similar.

Hunting

Crested Hawk Eagles take a range of prey, including birds up the size of chickens, small mammals, snakes, and lizards. They perch in an exposed location to hunt, usually high up; occasionally they choose someplace lower, such as on a fencepost or in the crown of a tree. They then swoop down to catch their prey on the ground, although birds are sometimes caught in trees.

Conservation status

Crested Hawk Eagles are the most widespread and common Asian hawk eagle, but the individual subspecies have much smaller ranges and are under threat from shooting and habitat loss. Subspecies N. c. andamanensis may have a range of less than 6,475 km², and N. c. vanheurni only 1,600 km². N. c. ceylanensis inhabits 65,000 km², however, and N. c. cirrhatus and N. c. limnaeetus even larger areas. The entire species has been evaluated as Least Concern by BirdLife International.