Family: Accipitridae
Genus: Spilornis
Species: S. perplexus

Ryukyu Serpent Eagles are small raptors endemic to two islands in Japan. They are sometimes classified as a subspecies of Spilornis cheela (Crested Serpent Eagle).

Physical Description:

Ryukyu Serpent Eagles are pale brown from above with small white spots along the shoulders. The black crown is edged with white and the underside is light brown with a rufous hue. There are brown markings along the throat and chest and white spotting on the flanks and belly. Wings are black with white edges on the wing coverts and the primary feathers have white tips. The tail is black with a white central band and, as with the wings, has a white tip. The eyes, lores, cere, and legs are yellow. They also have short, bushy crest which gives them a flat-headed appearance.

Juveniles are white along the head, crest, and underside with some streaking; there are also dark patches behind the eyes.

Size:

Length: 50-65 cm
Wingspan: 110-123 cm

Habitat and Distribution:

They live in subtropical evergreen forest from 0-500 meters above sea level. They are frequently seen soaring and perching on trees and poles.

Ryukyu Serpent Eagles are endemic to the Nansei-shoto islands (formerly called Ryukyu islands) of Iriomote-shima and Ishigaki-shima in Japan, from 24.25°N to 24.50°N. Adults are probably sedentary, though one vagrant was recorded on Yonaguni-shima, 65 km west of the other islands. There are an estimated 101-1,000 individuals.

Diet and Hunting:

They eat small prey such as snakes and frogs.

Reproduction:

No information.

Conservation:

Ryukyu Serpent Eagles are most likely under threat from habitat loss. They are not recognized by BirdLife International (see below Taxonomy).

Taxonomy:

Spilornis perplexus is treated as a subspecies of Spilornis cheela (Crested Serpent Eagle) by some authorities, but Ferguson-Lees, James and David A., Christie (2001) classified it as a full species. Therefore, it is tentatively listed as the separate species S. perplexus on this website.

Other Names:

Ryukyu Crested Serpent Eagle, Ryukyuslangeørn (Dutch), Ryukyu maduhaugas (Estonian), Serpentaire des Ryu Kyu (French), Serpentario delle Ryukyu (Italian), Kanmuriwashi (Japanese), Wezojad szarolicy (Polish), Hadiar sivolíci (Slovak).

Video of a Ryukyu Serpent Eagle:

References:

http://avibase.bsc-eoc.org/species.jsp?avibaseid=6C8C2A30F9445B4D
Global Raptor Information Network. 2012. Species account: Ryukyu Serpent Eagle Spilornis perplexus. Downloaded from http://www.globalraptors.org on 14 Feb. 2012
Ferguson-Lees, James, and Christie, David A. Raptors of the World. Houghton Mifflin Company, 2001.