The hunter hunted
The magnificent Pallas’ Fish-eagle is deemed to be Vulnerable, with a population of about 2,500 to 10,000 birds remaining in the wild. Besides direct persecution, humans contribute to the decline of this species through habitat degradation, pollution, and through draining or overfishing in lakes.
The large Pallas’ Fish Eagle (Haliaeetus leucoryphus), with its loud ‘kha-kha-kha-kha-kha…’ call, is an unmistakable bird. Mainly found close to freshwater bodies such as rivers and lakes, the eagle has a wide distribution range spanning over northern Central Asia and much of the northern Indian subcontinent. While the population in Central Asia migrates to escape the bitter cold, the population of the Indian subcontinent is more or less resident. But at several locations, mixed populations of migrating and resident birds exist during the breeding as well as winter season, suggesting that the migratory behaviour of this bird is poorly understood.
Pallas’ Fish-eagle sitting on tree branch | Photo: Dhritiman Mukherjee
The overall dark brown eagle has a light brown chest area and a white face. Although the diet mainly consists of fish, the bird has been observed to feed on waterfowl, reptiles and frogs in varying amounts. In fact, in some areas of its distribution, eagles have been reported to live on a completely fish-free diet. An opportunistic hunter, the eagle also scavenges whenever it gets a chance. Rather than diving into a water body, the Pallas’ Fish Eagle captures fish from the water’s surface. The eagle has been recorded to fly off with a Greylag Goose, which is slightly heavier than itself, and was also observed flying low over the water surface with a huge carp, weighing close 6 kg (double the weight of the eagle), before it was scared by gunfire to drop it. These are some of the greatest weight-lifting feats ever recorded for flying birds!
The eagle, although almost exclusively found along freshwater bodies, is related to sea eagles. It is believed that the marine eagle used to survive in the sea between the Indian subcontinent and mainland Asia before the two collided. Once the lands merged and the sea was drained out, the eagle adapted to a freshwater habitat. Like most other sea and fish eagles, the Pallas’ Fish Eagles build their nest in the form of large platforms atop tall trees. But eagles in Mongolia and Kazakhstan build their nests on ground.
Pallas’ Fish-eagle with catch | Photo: Dhritiman Mukherjee
The large range of the eagle is deceptive, as it is rare and lives in isolated populations throughout its range, breeding at very few locations. Wetland drainage, water pollution, agricultural expansion and human settlements have severely affected the eagle’s habitat. Felling of large trees leaves fewer places for the eagle to nest, while overfishing has resulted in depletion of prey. In India, the introduced Water hyacinth has impeded in the eagle’s hunting technique. Because of the small, declining population and degradation and disturbance at wetlands and breeding sites throughout its range, it is listed as Vulnerable by IUCN. Understanding the breeding ecology, providing protection to key populations, conserving wetlands within its range and promoting rural education are the proposed conservation exercises for this magnificent eagle.
Kingdom : Animalia
Phylum : Chordata
Class : Aves
Order : Accipitriformes
Family : Accipitridae
Genus : Haliaeetus
Species : H. Leucoryphus
Cover Photo: Dhritiman Mukherjee
Article originally published in Jan 2015 issue of Saevus Magazine
Read also: Junglimericks: In the Crazy Wilds of India
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