Madagascar Serpent-Eagle

The Madagascar serpent-eagle (Eutriorchis astur) is a rare species of bird of prey of the family Accipitridae, and found in northeastern Madagascar.

Description[edit]

The Madagascar serpent-eagle is medium-sized, with a body length of 22-26 inches, a wingspan of 35-43 inches, and weighs 24.6-28.2 ounces; females are slightly larger than males. In size, shape, and color it resembles the hawks of the genus Accipiter. Above the bird is dark-brown with darker banding throughout, which is particularly noticeable on the shoulders. The underside is white and also shows dark transverse banding, somewhat thinner, yet more densely placed than above. The long, brown, rounded tail has five to seven black cross bands. The back of the head bears an erectile hood. The iris of the eye is yellow. The legs are light yellow and look rough and gnarled due to the very strong scaling. The beak is black. The wings are relatively short and rounded.

More often heard instead of seen, the bird can be identified by the calls alone, which are very striking. The call is a loud, wide-bodied "wäh ... wääh..waäh", often followed by a quieter "uug".

Range and habitat[edit]

The species is endemic in northeastern Madagascar. It lives within pristine, untouched rainforests, from in 0 to 3,600 feet sea level, and most probably within a band of altitude of 1,200 to 3,000 feet. The total distribution area of ​​the species is estimated at only 6,409 square miles.

Diet[edit]

The name probably goes back to ancient times, in which it was said the bird killed large, venomous snakes. Despite the name, the Madagascar serpent-eagle consumes a large number of other species; in one example, 83 percent of the prey items fed to chicks in the nest consisted of chameleons and geckos, another 16 percent were frogs. Only 2 snakes were fed, in addition to a bat. Reports of lemur and poultry captures are most likely due to confusion with the Henst's goshawk (Accipiter henstii), which is found in the same habitat and closely resembles it^[3].

Breeding[edit]

Two relatively-small nests were recorded; one in 1997^[4], the second in 2000. Both nests were found in the canopies of large epiphytic ferns (Asplenium nidus) more than 60 feet high. The first nest was found on November 7, and within was a single egg which hatched on November 21 after a breeding season of probably around 40 days; the second nest's egg hatched on November 9. The nestling period for both was about 58-62 days, with the chicks cared for by both parents until the age of 6 weeks^[5].

Threats[edit]

Until the beginning of the 1990s, the Madagascar serpent-eagle was known only from 11 specimens collected between 1874 and 1930, and was considered lost and probably extinct. In 1990, a dead eagle was found in the Ambatovaky Reserve, and in 1997 a nest was discovered. The Madagascar serpent-eagle is apparently very shy and careful and therefore very easy to miss. The evidence works best on the striking calls. From 1993 to 1998, 15 individuals were observed at 9 different locations.

The population is currently estimated at 250 to 1000 individuals. The main threat is persecution, forest destruction by slash-and-burn and uncontrolled forest fires for arable land and logging. In addition, it is suspected that a loss of key prey species for the exotic pet trade (chameleons Furcifer and Calumma spp; geckos Uroplatus spp) may be a factor in the bird's reduction in numbers^[6].

References[edit]