The Pallas’s Fish Eagle (Haliaeetus leucoryphus)
An endangered eagle species included in the IUCN Red List, the Pallas’s Fish Eagle is generally found in wetland habitats on the fool fills of the Himalayas including areas in Pakistan, North India, Bhutan, Bangladesh and Myanmar where it spends its breeding period. The non breeding period may be spent at cooler higher latitudes extending to North and Central Asia, Southern Russia, Kazakhstan to Mongolia and China. They are rarely seen in Nepal. The elevation range of the species extends from 75 to 4880 meters where the birds may migrate in summers. A small part of the breeding population in India may be resident in India. The population has rapidly decreased because of habitat destruction. The adult bird is fairly large having a length of 72 to 85 cms. and a wing span of 180 to 215 cms. Females are generally larger and reported to weigh between 2.1 to 3.7 kg whereas the males may weigh 2.03 to 3.3 kg. The female has a lighter coloured head and mouth. This specimen appears to be a female. Juveniles may be mainly dark brown with pale streaks. There is no seasonal variation in morphology.
Vocalisation is distinct. Birds may vocalise while flying or while perched on trees. When calling from a perch the bird stretches its body vertically and pointing its head and bill also vertically to the sky, opens the bill wide with every note. Vocalisations help in communication. Pairs maintain contact through long distance calls.
The adults exhibit a loyalty and preference for the same nesting sites. The same nesting areas have been occupied for almost half a century and the same trees have been used over period extending from 5 to 15 years. The same nest can be used for many years. Eggs are about 7 cm x 6cm, while and generally 2 to 3 in numbers. Incubation is mainly by females. They also exhibit a high degree of preference for the same non breeding home range and may return to the same in subsequent years.
The species is monogamous. Nests are large about 90 cm. Dia and 42 to 45 cm. deep. One nest was observed to weigh almost 77 Kg. Both sexes assist in nest building which may take almost a month. Males engaged more in bringing the nest material while females worked more towards building the nest. Nest densities have been reported from 3.7 to 4.8 nests per 100 sq. kms. The home range extends from 0.08 sq. kms to 34 sq. kms.
The Pallas’s eagle usually feeds on fish but its food base can also include water birds, rodents, frogs, reptiles, turtles, offal and carrion or even human bodies. Instances of preying on demoiselle crane, Bar headed goose, Ruddy Shelduck etc. have been reported. It can fly away with prey considerable larger than itself.
The birds often preen themselves while perched. This specimen was observed eating the preened material (may be some down feathers, salt or even parasites?).
The global population was estimated between 1000 to 2500 mature individuals in 2017. The overall population is declining. Habitat loss and degradation due to encroachment and destruction of wetlands, felling of trees near wetlands, siltation of water bodies and reduction of prey base have been importance triggers.
©Srimaa Communication
Credits- Dr. Yashpal Singh, Mrs. Neena Singh, Mr. Rajesh Bedi, Manoj Kumar Yadav