Skip to main content

Javan hawk-eagle (Nisaetus bartelsi)

The Javan hawk-eagle or Javanese eagle or Elang Jawa (Nisaetus bartelsi) is one of the endemic eagle species on Mount Merapi, medium to large, and slim with a length of up to 70 cm. The reddish-brown head (cadre) has a crest of 2 to 4 feathers for up to 12 cm long and a yellowish brown neck.

Black crested with white ends, black crown and mustache, while back and wings are dark brown. The esophagus is whitish with a long black line in the middle. The chest has black streaks spread over the brownish yellow which eventually turn into a dense line pattern and red transverse above the whitish color of the abdominal and leg feathers.

Dlium Javan hawk-eagle (Nisaetus bartelsi)


Feathers cover the legs to close to the base of the finger. A brownish tail with four dark lines and a wide cross is clearly visible on the lower side, and the tip of the tail is thin white striped. Females are similar in color, but have a slightly larger size.

The iris is yellow and brownish, half-black, sera yellowish, and yellowish legs. Young birds have a head, neck and lower body with brown wood and without streaks or lines.

Javanese eagles fly and shout loud and repetitive sounds, like klii-iiw, which vary from one to three syllables. High and fast pitched sounds like kli-kli-kli-kli-kli. This sound is similar to Spizaetus cirrhatus, although it has clear differences in tone.

The distribution of these eagles is limited to Java and only in primary forests in the transition from the lowlands to the mountains. Most are found in half the southern hemisphere of Java where these birds live specializing in sloping areas, but have cruises to the coast in the lowlands and up to 3,000 meters above sea level.



Eagle is one of the top predators in the food chain cycle of a forest ecosystem. This bird hunts from a place perched on tall trees in the forest to glide and ambush reptiles, birds, pigs, native chickens, squirrels, bats, civets, and monkeys.

The laying period begins in January to June in a pile of leafy branches arranged in trees as high as 20-30 meters. Only one egg and was incubated for 47 days. Nests are generally in Rasamala (Altingia excelsa), pairs (Lithocarpus sundaicus), tusam (Pinus merkusii), puspa (Schima wallichii), and ki sireum (Eugenia clavimyrtus).

Dlium.com Javan hawk-eagle (Nisaetus bartelsi)


Javanese eagle was known in 1820 when van Hasselt and Kuhl collected two specimens for the Leiden Museum, but until the end of the 19th century it was still considered as Spizaetus. The IUCN included Javanese eagles in the status of EN (Endangered) and the Indonesian Government designated them as animals protected by law.

The bird monitoring team at the Mount Merapi National Park Center conducted regular observations on eagles and other raptor to monitor this bird on Mount Merapi. Javanese eagles are less competitive than Black Hawk (Ictinaetus malayensis) and Bido Eagle (Spilornis cheela), also by habitat degradation.



Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Genus: Nisaetus
Species: N. bartelsi

Popular Posts

Humpback whales (Megaptera novaeangliae) manufacture bubble-nets as tools to increase prey intake

NEWS - Humpback whales ( Megaptera novaeangliae ) create bubble net tools while foraging, consisting of internal tangential rings, and actively control the number of rings, their size, depth and horizontal spacing between the surrounding bubbles. These structural elements of the net increase prey intake sevenfold. Researchers have known that humpback whales create “bubble nets” for hunting, but the new report shows that the animals also manipulate them in a variety of ways to maximize catches. The behavior places humpbacks among the rare animals that make and use their own tools. “Many animals use tools to help them find food, but very few actually make or modify these tools themselves,” said Lars Bejder, director of the Marine Mammal Research Program (MMRP), University of Hawaii at Manoa. “Humpback whales in southeast Alaska create elaborate bubble nets to catch krill. They skillfully blow bubbles in patterns that form a web with internal rings. They actively control details such ...

Sweetpotato bug (Physomerus grossipes)

Kutu ketela or sweetpotato bug ( Physomerus grossipes ) is an insect species in Coreidae, brown with black legs, adults growing about 2 cm long, oval shaped, segmented antennas, heavily veined membranes, metathoracic odor glands and enlarged rear tibia. P. grossipes generally live in Leguminosae and Convolvulaceae especially sweet potato ( Physomerus grossipes ), pink morning glory ( Ipomoea carnea ), purple beans ( Vigna unguiculata ), Asian pigeonwings ( Clitoria ternatea ) and common bean ( Phaseolus vulgaris ). Sweetpotato bugs suck liquid from the stem which causes plants to wither and disrupt fruit production. P. grossipes places eggs at the bottom of the leaves or stems or grass around them. Females are very protective of their children, keeping eggs and nymphs from predators as the most famous example of maternal care in Coreidae. Even so, about 20% of eggs are eaten by predators such as ants and 13% are lost by parasitoid predation by chalcid wasps which lay eggs in egg...

Yellow potter wasp (Delta campaniforme)

Yellow potter wasp ( Delta campaniforme ) is a species of animal in Vespidae, solitary wasp, shiny yellow, shiny black, dull black and brown with a yellow striped belly, a long and narrow waist, a nest built using mud and a circle attached to a cliff. D. campaniforme has a black head with a yellow plot in the center and two transverse plots on the right and left. A pair of black eyes. A pair of antennas, long, yellow with a black base and tip. The back is yellow and black. A large black plot semicircle at the top of the front. The two plots form a circular line at the top of the back. A pair of wings is brownish black and transparent. The stomach has the shape of a water droplet, pointed tip, black with yellow and black segments, alternating to form stripes. Linear folds on the sides. The underside of the front is brown and large. The middle section has alternating yellow and black segments that form stripes. The stomach and back are connected by a long, narrow, downward curved pipe...