Bambang M. Contributor Yogyakarta

Among the endangered eagle species of Accipitridae, the black eagle (Ictinaetus malayensis) may be the most fierce-looking, with a large, jet-black, raptorial body that can grow to almost 70 cm long. Fierce though it may look, it is rather meek when it comes to reproduction, laying eggs only once in two years. "This bird's rather strange behavior is that it has a low interest in procreation," said Dewi, member of a Yogyakarta-based environmental activist group called Raptor Indonesia (RAIN).

Dewi graduated from the School of Biology at Gadjah Mada University in Yogyakarta, and has researched the black eagle extensively.

In 2000, she was observing a black eagle couple and their chicks in a nest in the Japanese Cave of Plawangan Turgo nature reserve, located near the southern slope of Mount Merapi.

She found out that, after the young chicks had been abducted by locals -- and later sold at Ngasem bird market in Yogyakarta -- the female eagle did not lay eggs for two years.

By 2002, however, the nest -- measuring up to 140 cm in diameter and perched on top of a Erythrina Sp. tree -- boasted a new batch of eggs.

While the reproductive cycle of a black eagle is two years, that of the Javan eagle Spizaetus bartelsi, another rare species, is shorter, occurring in a two- to three-month cycle. Indonesian ornithologists have yet to uncover why black eagles have such a long reproductive cycle, and the breeding habit of birds in general are still vague.

"We've only got an inventory of species," said Ign. Pramana Yua, an ornithologist at the School of Biology of Atma Jaya University in Yogyakarta. A black eagle's mating period usually falls between January and February. In March, the female eagle lays a single egg and incubates it for 47 days. During this time, it will rarely leave its nest, and the male eagle is responsible for finding food for the two of them. When the chick has hatched, the mother bird will rear it for about two years, although the chick will learn to fly when it is only 6 to 7 weeks old.

A black eagle generally has two or three nests, built about 500 meters away from each other, but it uses only one.

"We don't yet know why," said Sidik of KANOPI, a locally based, environmental non-governmental organization (NGO) now engaged in research on this raptorial bird.

Meanwhile, John McKinnon, Karen Phillips and Bas van Balen write in their book, Birds in Sumatra, Java and Bali, that the black eagle usually pillaged the nests of their own kind. Frequently, the black eagle builds its nest in a dadap tree (Erythrina Sp.) or kikepas tree (Angelherdia Sp.) and the pine tree (Pinus merkusii), choosing a tree that grows at the edge of a ravine.

"The reason for this is that it needs a wide-open space in which it can make use of the warm air current to teach the young to fly within a short time," said Abrar, a KANOPI activist. In addition, the tree it selects for its nest is usually protected by strong winds, said Dwi Lesmana of Birdlife Indonesia.

A black eagle mainly feeds on rats, squirrels, birds' eggs and smaller birds. An adult black eagle can eat two to three rats a day, but will eat more when it is caring for its young.

This raptorial bird usually looks for prey within a radius of 20 to 30 square kilometers, beginning the hunt about 7 a.m. At the break of dawn or on a cloudy day, it waits for prey atop a tree branch. Later in the morning or on a bright day, however, it will soar overhead and let out a loud shriek to swoop down quickly and seize its prey.

Eagles are highly territorial birds, and sometimes, when rival eagles trespass a black eagle's territory, the black eagle will attack the intruder in mid-flight. A black eagle will also undulate its body to indicate that another eagle is flying over its territory.

Found only in lush, forested mountain areas, outside Indonesia, the black eagle is found in India, China and other Southeast Asian countries. Mountainous areas of Indonesia that are home to these majestic birds include the skies above Mount Merapi, Mount Slamet, Mount Lawu and Mount Gede-Pangrango.

This raptorial bird can generally be found on the islands of Sumatra, Kalimantan, Sulawesi, Java and Maluku, although the population has declined in the wild.

The black eagle has been listed as a protected bird under Government Regulation No. 7/1999 on protected animals and plants. In CITES (Convention on International Trade in Endangered Species), the black eagle has been listed in Appendix II, meaning that it is not yet on the brink of extinction, but that it will quickly become extinct if the trading of this bird is not tightly regulated.

In a survey that Dewi conducted in four regencies -- Kulonprogo, Wanagama Forest in Gunungkidul, Pacitan and Bantul -- between September and October 2002, for example, only two black eagle couples were found in the wild, namely in Menoreh Hills of Kulonprogo and in Wanagama Forest.

"Residents in the areas say the bird is rarely seen now," she said. It is the destruction of this bird's habitat that has led to the decline in its population. Most low-lying forest areas in Indonesia, which are the bird's main habitat, are scarcely found today. This is also why this bird is now found only in mountainous areas. Even this limited habitat must be shared with other raptorial birds.

Dwi Lesmana said the life of a black eagle relied very much on forest sustainability.

Although this bird is protected by law, it is still a hunted for sport. If someone wants to keep the bird as pet, he must take a young bird, because an adult black eagle is prone to severe levels of stress in captivity that will eventually kill it. Given that the habitat of this bird is now much reduced, that it is still a target of hunters, and that it breeds only once in two years, the population of the black eagle is increasingly threatened.

"In the next decade or two, the population of black eagles will reach a very critical level. That's why we must collect as much data as possible about this bird's behavior to ensure that we can conserve this species properly," said Abrar.

In the case of the Javan eagle, he said, the study of its behavior was begun only when the bird was already on the brink of extinction. Breeding this species in captivity remains difficult as it will need a very large cage, and the cost of a breeding program will be extremely high.

Sidik said that the key to maintaining the population of this bird was to ensure that its habitat would not be reduced further, and to carry out intensive conservation campaigns. The extinction of the black eagle will disrupt the balance in the ecosystem, as this bird is a top predator which controls the population of its prey, such as rats and other rodents.