Javan Hawk-Eagle
Nisaetus bartelsi
Medium-sized eagle with short, rounded wings. Adult is dark brown above and white with heavy streaking and barring below. Perched birds show a prominent vertical crest. When in flight, note prominent “fingers”, black-striped white throat, and bold black banding on the flight feathers and tail. Juvenile has a pale tan head and underparts, a shorter crest, and paler black banding on the wings and tail. Pale morph Changeable Hawk-Eagle can be similar, but note present species’ more densely patterned underparts and wings, taller crest, and tan (not white) head in juveniles. Endemic to Java, where it is now largely limited to foothill and montane forests. Soars often, but also frequently perches silently in the canopy. Quiet, but occasionally gives thin yelping screams.
Identification
The hawk-eagle is approximately 60 cm (24 in) long. Its head and neck are rufous and it is heavily barred black below. This majestic and intricately patterned eagle has a long, black crest on its head; this crest is held almost vertically and is tipped with white. The crown is black, topping a chestnut head and nape. The back and wings are dark brown, fading to a lighter brown tail which has wide cream stripes. The throat is creamy white with a black stripe, running to the whitish breast and underparts, which are heavily barred with chestnut. Juvenile birds are similar in colour, but have plainer underparts and a duller head. The sexes are similar.
Taxonomy
Because of the plumage variability of Spizaetus eagles, the Javan hawk-eagle was not recognised as a full species until 1953. It was previously placed in Spizaetus. A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level.
- Scientific name
- Nisaetus bartelsi
- Authority
- (Stresemann, 1924)
- Order
- Accipitriformes
- Family
- Accipitridae
- Genus
- Nisaetus
Range and habitat
An Indonesian endemic, the Javan hawk-eagle occurs in humid tropical forests of Java. Its range in East Java includes Sempu Island, Bromo Tengger Semeru National Park, Meru Betiri National Park and Alas Purwo National Park. It can also be seen in captivity in zoos like Kebun Binatang Bandung
- Migration
- Resident species
Behavior
The Javan hawk-eagle is believed to be monogamous. The female usually lays one egg in a nest high on top of a forest tree. The diet consists mainly of birds, lizards, fruit bats and mammals.
Conservation
It is one of the rarest raptors. Due to ongoing habitat loss, small population size, limited range and hunting in some areas, it is evaluated as Endangered on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES.<p>In February 2012, there were only around 325 pairs of Javan hawk-eagles living in the wild, mainly in Malangbong, West Java and some in East Java. In Central Java, Mount Merapi has been deforested by eruptions and Dieng Plateau has been deforested by agriculture. The adaptation of the bird is very difficult due to their preference for Rasamala trees and Javanese rats for their diet. Ideally the population should be 1,450 pairs and without conservation the eagle is predicted to go extinct by 2025.
- Population trend
- declining
Photos
Distribution
Bird Calls
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