Hunted, sexually lazy eagles face extinction

Hunted, sexually lazy eagles face extinction

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.