[4] The species was described in 1935 by Ernst Mayr who noticed that earlier observers had overlooked it, thinking it was a juvenile of the white-bellied sea eagle.

[5][page needed][6] Both share a dark bill, talons, and eyes with the other Gondwanan sea eagles.

The eagles inhabit coastal forests and lakes up to an altitude of about 1500 m above sea level.

Uniquely among sea eagles, this species has an entirely dark tail throughout its life.

The diet consists of mainly of tideline carrion, fish, molluscs, crabs, tortoises, and sea snakes, and more rarely birds and megabats snatched from the rainforest canopy.