Grey-headed fish eagle

The grey-headed fish eagle (Icthyophaga ichthyaetus) is a large bird that lives in Southeast Asia. It loves to eat fish and is often seen near rivers, lakes, and other water bodies. Adult grey-headed fish eagles have a dark brown back, a grey head, a lighter belly, and white legs. Young birds look paler and have darker streaks on their feathers.

This bird is sometimes mixed up with two other eagles: the lesser fish eagle and the Pallas's fish eagle. The lesser fish eagle looks similar but is smaller, while the Pallas's fish eagle lives in the same places and also eats fish, but it is bigger with longer wings and darker belly feathers. In Sri Lanka, people often call this eagle the "tank eagle" because it likes to visit irrigation tanks to find food.

Taxonomy

The grey-headed fish eagle was first described in 1841. It belongs to the order Accipitriformes and the family Accipitridae, which includes many birds of prey, except for ospreys and falcons. It is part of a special group called Haliaeetinae, which also includes sea eagles. This group is closely related to another group called Milvinae.

Description

The grey-headed fish eagle is a medium-sized bird that eats fish. It has a small bill, a long neck, and short legs with strong claws. Its wings are not very long.

Adult grey-headed fish eagles have a dark brown body, a grey head, and a lighter belly. Their legs are white. Young birds look paler and have darker streaks on their feathers. As they grow older, their feathers change to the adult colors.

Distribution and habitat

The grey-headed fish eagle lives in many places from India and Southeast Asia all the way to the Philippines. It is not very common, and in some areas it is quite rare.

This bird likes to stay near low land forests, usually not higher than 1,500 metres above sea level. It builds its nests close to water, such as slow rivers, lakes, and swamps. It can also be found near coastal areas and irrigation tanks.

Ecology and behaviour

The grey-headed fish eagle is a bird that stays in one place and can live alone or in pairs. It does not move around much during the year. Young birds leave their parents' area to look for food or mates.

This eagle likes to sit upright on branches near water and sometimes flies down to catch fish. When it flies, it looks heavy and flaps its wings strongly.

During the time when these birds have babies, which is usually between November and May in most places, they build a very big nest made of sticks. The nest can be up to 1.5 metres across and, if used many times, can become up to 2 metres deep. They put green leaves inside the nest. The nest is built high in trees, usually near water and far from people, so they can easily find food.

These birds usually lay two white eggs. Both the male and female take care of the eggs and the baby birds. The eggs take between 45 and 50 days to hatch, and the baby birds can fly after about 70 days.

As their name suggests, grey-headed fish eagles mainly eat fish, but they will also eat dead fish, reptiles, birds, and small mammals. They usually catch fish from a spot close to the water, flying down quickly to grab it. Sometimes, if the fish is too heavy, they pull it to the bank to eat. They can also catch fish in rough water like rapids.

These eagles can also be a threat to other animals like monkeys and orangutans in some areas.

They make several different calls, including a gurgling sound, a loud high-pitched scream, and other noisy cries. They call loudly during the time they have babies and can even call at night.

Threats

The grey-headed fish eagle faces many challenges that are causing its numbers to drop. One big problem is the loss of wetland areas where these birds live. This happens because of cutting down forests, fishing too much, and pollution. These changes make it harder for the eagles to find food and build nests.

In places like Cambodia, building dams on the Mekong River could also hurt the eagle’s habitat. The dams might change the water patterns in the Tonlé Sap, which is an important area for these birds. Scientists have noticed that areas with more people have fewer eagle nests, showing that human activity is a big part of the problem.

Conservation status

The grey-headed fish eagle is considered Near-Threatened on the IUCN Red List. Scientists think there are between 10,000 and 100,000 adult birds, but because numbers are dropping quickly, the real count may be closer to 10,000. These birds live across a large area of 5 million square kilometers, but they are only found in some places.

There are no special plans to protect this bird right now, but each year since 2006, scientists have watched the birds that live and raise their young in a protected area near Tonlé Sap Lake in Cambodia. This helps them learn more about the birds. Suggestions to help these birds include finding important areas for them, protecting forests they use, and teaching local people to care for wetland areas.