Javan hawk-eagle (Spizaetus bartelsi)

Spanish: Aguila-azor de Java
GenusSpizaetus (1)
SizeLength: 60 cm (2)

The Javan hawk-eagle is classified as Endangered (EN) on the IUCN Red List 2007 (1) and is listed on Appendix II of CITES (3).

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 (2).

Endemic to Indonesia, the Javan hawk-eagle is restricted to the remaining patches of forest on the island of Java (2).

Normally inhabiting primary humid forest, the Javan hawk-eagle has also been recorded in secondary forest, production forest and tropical semi-deciduous forest. It is found at all altitudes, but is most common between 500 and 1,000 metres above sea level (2).

A monogamous species, Javan hawk-eagles remain with the same partner year after year, mating between January and June. Nesting in trees, just one egg is laid each year. The female incubates the egg for 47 days, during which time the male hunts to feed both himself and the female. After hatching, the female also hunts, providing the chick with meat for a relatively extended period. Even after fledging, the young bird will remain with its parents, living in their territory for more than a year. It will be three or four years before it forms a pair and breeds (4).

The Javan hawk-eagle hunts mainly from the branches of small trees, where it watches for small to medium-sized tree-dwelling mammals such as tree shrews, squirrels, fruit bats and occasionally young monkeys. It is also known to eat birds and reptiles when possible (5).

Habitat loss caused the initial decline of this bird, as the increasing human population of Java relies heavily on the natural resources of their island, particularly its forests. Conversion to agriculture, urban development and uncontrolled fire, even in protected areas resulted in a sharp decline that prompted the Indonesian government to promote the Javan hawk-eagle to the status of ‘national bird’. However, this move rebounded, as trade in the species multiplied in response to its new significance and consequential desirability (2).

The range and population of this species have been surveyed, revealing its presence in Gunung Haliman, Gunung Gede-Pangrango and Meru Betiri National Parks. However, despite the strict legislation protecting the eagle from hunting and trading, it faces serious problems through ineffective enforcement of the law. An action plan has been compiled and conservation awareness programmes have begun. The action plan suggests that thorough ecological studies are performed to allow the implementation of management plans. Nest-guarding is being seriously considered as an option to enforce legislation protecting this beautiful species (2).

For further information on the Javan hawk-eagle see:

To find out more about Javan hawk-eagle conservation projects, see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. IUCN Red List (May, 2008)
  2. BirdLife International (March, 2005)
  3. CITES (March, 2005)
  4. Nijman, V., Van Balen, S. and Sozer, R. (2000) Breeding biology of Javan hawk-eagle Spizaetus bartelsi in West Java, Indonesia. Emy, 100: 125 - 132.
  5. BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.