Poachers robbing Indonesia of the rarest raptor

Indonesia’s national icon  the Javan hawk-eagle  has become the favorite  target of illegal javan_hawk_eagle_211traders for the past few years. It has been considered the most at risk species in Indonesia. The Javan hawk-eagle is considered one of the world’s rarest birds, according to Malaysia-based TRAFFIC, a wildlife body that works to ensure that trade in wild plants and animals does not pose a conservation threat.(1)

The Javan Hawk Eagle Spizaetus bartelsi is native to the island of Java (Indonesia) where it lives isolated in the rainforests from the lowlands to the mountains. It inhabits rainforests from 3,000 m (3.94 ft) in the western part of the islan to sea level. Until recently it was thought that the species only occurs from western most through central to the eastern parts of the island, but is best preserved in the forest areas.(2)

In the tropical forest raptors are difficult to see, so Javan Hawk Eagles can be best seen during periods of strong thermal activity, when soaring, the wings are held in a slight V-shape and without flapping so the bird can be observed at length, showing off the pattern of banding onjavan-hawk-eagle-final thunderwing. When flying the wing-beats are regular and rather fast, but gliding the wings may be held slightly swept back. Flying adults show a distinctive wing pattern when seen from below (See above image). If observed from above the bird it looks much darker.  Its banding pattern  can still be seen. Their longish head and tail impart a rather slender appearance. The tail is held straighter is occasionally spread out, and in both positions the banding pattern can be seen clearlyin the adult birds.

Juvenile birds show less pronounced banding and the banding pattern on both wings and tail is incomplete. Their “wings appear white with grey-buff primaries and cinnamon-brown underwing-coverts, whilst the white patch in between is triangular, with the tip at the carpal joint . One of the most characteristic features of the adult is the chestnut-colored head with a black crown and yellow-brown nape (appearing golden in sunshine), which always contrast with the much darker body and wings.

The crest is seldom seen on a flying bird. Flying immatures appear cinnamon-brown from below with a similar, but less pronounced, wing pattern.(3)

Radio tracking has provided information on prey species, breeding biology and the estimated home range. Small mammals such as treeshrews, squirrels, bats, rats and other small rodents are the preferred prey, but birds, snakes and lizards are also taken. The Javan Hawk-eagle may breed at anytime of the year but usually between January and July. It is sexually mature at the age of three to four years, breeds every two years and lays only one egg. “The most recent estimates c. 142-204 breeding pairs or c. 600-1000 individual birds, including juveniles remain.” (2)

Endangered

This low number, the continuing habitat destruction, as well as the trade in the species, the species has never bred in captivity and is endangered.2000-3554

Resources

1. Excerpts courtesy of Terra Daily: Smugglers target Indonesia’s rare Javan hawk: official the rare Javan Hawk-eagle.- Staff Kuala Lumpur (AFP) February 6, 2009.

terradaily.com/SmugglerstargetIndonesiasrareJavanhawk

2. Field identification of the Javan Hawk Eagle Spizaetus bartelsi
orientalbirdclub.org/Nijman-HawkEagle

3. en.wikipedia.org/wiki/Javan_Hawk-eagle

Ecology and conservation of endangered Javan Hawk-eagle Spizaetus bartelsi
– Dewi M. Prawiradilaga Division of Zoology, Research Center for Biology, LIPI
November 17, 2006. .jstage.jst.go.jp/article/os

Images

1. Courtesy of thairaptorgroup.com/TRG/files/javanhawkeagle

2. Courtesy of Flicker and  Google Images  http://farm1.static.flickr.com/

3. Map courtesy of www.birdlife.eu

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