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 ...

Purhepecha oak (Quercus purhepecha), new species of shrub oak endemic to the state of Michoacán, Mexico

NEWS - In Mexico, several Quercus shrubby species are taxonomically very problematic including 8 taxa with similar characteristics. Now researchers report the purhepecha oak ( Quercus purhepecha De Luna-Bonilla, S. Valencia & Coombes sp. nov.) as a new tomentose shrubby white oak species with a distribution only in the Cuitzeo basin in the Trans-Mexican Volcanic Belt (TMVB). Quercus Linnaeus (1753) subdivided into 2 subgenera and 8 sections of which section Quercus (white oaks) has the widest distribution in the Americas, Asia and Europe. This section is very diverse in Mexico and Central America with phylogenomic evidence indicating recent and accelerated speciation in these regions. The number of shrubby oak species in Mexico is still uncertain. De Luna-Bonilla of the Universidad Nacional Autónoma de México and colleagues found at least 3 taxa in the TMVB, specifically Quercus frutex Trelease (1924), Quercus microphylla Née (1801) and Quercus repanda Bonpland (1809). In 2016,...

Cempaki (Termitomyces microcarpus)

Cempaki ( Termitomyces microcarpus ) is a species of fungus in the Lyophyllaceae family. It grows wild in tropical Asian forests near termite nests. It is rarely reported in urban areas. It is edible and known for its deliciousness, high nutritional value, and difficulty in cultivating. In Indonesia, it is used as an alternative food ingredient. T. microcarpus is the smallest of the Termitomyces species, umbrella-shaped, plain white, measuring 5 cm tall and 2.5 cm wide. It grows in dense clusters on surfaces and forms a mutualistic relationship, requiring the metabolic activity of termites as a substrate for growth. This species is known for its deliciousness, rich in nutrients, and has potential bioactive properties, such as helping lower cholesterol and acting as a tonic. Currently, it is difficult to cultivate on a large scale, and people rely solely on wild harvests. This mushroom is highly favored for its savory, delicious flavor and soft, chewy texture. It is often stir-fried ...