With tendencies towards piracy, the Pallas’s fish-eagle is opportunistic and generalist in its feeding habits, feeding on both live prey and carrion, and forcing other birds to surrender their prey. The Pallas’s fish-eagle will even steal fish from fish farms and fishermen. It feeds mainly on fish, capturing them at the water’s surface rather than plunge-diving. It is also known to consume frogs, turtles, reptiles, waterfowl and nestling birds. Diet composition varies widely with region, being entirely made up of frogs and turtles in one region, but entirely of waterfowl in a fishless lake in the Punjab Salt Range (6).
The breeding season also varies geographically, beginning in March in the north of the range, but in early November in the south. Nests are built by both the male and female of a monogamous pair at the highest point of trees that stand on the banks of rivers or close to lakes. In Mongolia and southern Kazakhstan, nests may also be built on the ground next to lakes. Constructed over the course of a month, the nest consists of a huge platform of sticks lined with hay, rushes, straw, fine twigs and green leaves. One to three eggs are laid, hatching 40 to 45 days later, each a couple of days apart. Invariably, the last chick to hatch will die, as it cannot compete effectively with its older siblings for food from its parents. Both the male and female care for the chicks, bringing food to the nest and defending them from predators. Once fledged, the young will remain in the vicinity of the nest until they are skilled at flying (6).
Whilst this species is known to be migratory, its movements are not understood. Individuals from regions with climatic extremes, where lakes and rivers may freeze over during winter, are more likely to migrate south in the non-breeding season. Some individuals from a given area might be residents, while others from the same region are migratory, leading to confusion over the purpose of the migrations and the cues that trigger them (6).