Crested Serpent-Eagle

This medium-large, dark brown eagle is stocky, with rounded wings and a short tail. Its short black and white fan-shaped nuchal crest gives it a thick-necked appearance. The bare facial skin and feet are yellow. The underside is spotted with white and yellowish-brown. When perched the wing tips do not reach until the tail tip. In soaring flight, the broad and paddle-shaped wings are held in a shallow V. The tail and underside of the flight feathers are black with broad white bars. Young birds show a lot of white on the head. The tarsus is unfeathered and covered by hexagonal scales. The upper mandible does not have an overhanging festoon to the tip.

Size. This species of serpent eagle manifests an unusual amount of size variation across its assorted subspecies. Total length of fully-grown crested serpent eagles can vary from 41 to 75 cm (16 to 30 in) and wingspan can vary from 89 to 169 cm (2 ft 11 in to 5 ft 7 in). The largest proportioned race appears to be the nominate, S. c. cheela, with a wing chord of 468 to 510 mm (18.4 to 20.1 in) in males and 482 to 532 mm (19.0 to 20.9 in) in females, tail lengths of 295 to 315 mm (11.6 to 12.4 in) and tarsus length of 100 to 115 mm (3.9 to 4.5 in). In comparison, S. c. …

The crested serpent eagle is a reptile eater which hunts over forests, often close to wet grassland, for snakes and lizards. It has also been observed to prey on birds, large insects like grasshoppers or locusts, amphibians, mammals, fishes, termites and large earthworms. It is found mainly over areas with thick vegetation both on the low hills and the plains. This species is a resident species, but in some parts of their range they are found only in summer. The call is a distinctive kluee-wip-wip with the first note being high and rising. They call a lot in the late mornings from their perches where they spend a lot of time and they rise on thermals in the mornings. In southern Taiwan, males have a larger home range than females. Males on average had a home range of 16.7 km2 while females used about 7 km2. When alarmed, they erect the crest and the head appears large and framed by the ruff. They will sometimes follow snakes on the ground. They roost in the interiors of trees with dense foliage. A radio-telemetric study of the species in Taiwan found that the birds spend 98% of the day perched and usually finding food in the morning hours. They appear to use a sit and wait foraging strategy.

The breeding season begins in late winter when they start courting and establishing territories. The eggs are laid in early summer. …