The Black Eagle is a large raptor at about 70–80 cm in length. Adults have all-black plumage, with a yellow bill base and feet. The wings are long and pinched in at the innermost primaries giving a distinctive shape. The tail shows faint barring and upper tail covers paler. When perched the wing tips reach till or exceed the tail tip. The wings are held in a shallow V in flight. Seen on hot afternoons, scouring the treetops for a nest to maraud, this bird is easily spotted by its jet black color, large size, and a ‘characteristic’ slow flight, sometimes just above the canopy.
Sexes are similar, but young birds have a buff head, under parts and under wing coverts. The wing shape helps to distinguish this species from the dark form of Crested Hawk-Eagle. The tarsi are fully feathered and the toes are relatively stout and short with long claws that are less strongly curved than in other birds of prey
The Black Eagle eats mammals, birds and eggs. It is a prolific nest-predator and is known for its slow flight just over the canopy. Due to this eagle’s ability to remain aloft for long periods with minimal effort, the Lepcha people of India’s Darjeeling District described it as a bird that never sat down. The curved claws and wide gape allow it to pick up eggs of birds from nests. Along with Swallow-tailed Kites they share the unique habit of carrying away an entire nest with nestlings to a feeding perch. Squirrels, macaques and many species of birds emit alarm calls when these birds are spotted soaring over the forest. The Indian Giant Squirrel has been noted as a prey of this species and young Bonnet Macaque’s may also fall prey to them.