Although, as its name suggests, it feeds extensively on fish, in some areas it preys on flamingos and other water birds. It is also know to eat carrion and is classified as a kleptoparasite (it steals prey from other birds). Goliath herons are known to lose a percentage of their catch to fish eagles. Their main diet is fish, sometimes dead, but mostly caught live, Catfish and lungfish are caught most frequently. Larger prey are eaten on the ground next to the water.
The African fish eagle has two distinct calls. In flight or perched, the sound is something like the American bald eagle, When near the nest its call is more of a 'quock' sound, the female is the little shriller and less mellow than the male. So well known and clear is the call of his bird that is often known as 'the voice of Africa". The African fish eagle is usually seen is pairs inside and outside the breeding season, even sharing kills made by either of them, They spend more time perched than flying, and usually settle for the day by 10am, having made their kill, although they will kill at any time of the day.
It is most frequently seen sitting high in a tall tree from where it has a good view of the stretch of river, lake shore or coastline, which is its territory. Near a lake with an abundant food supply, a pair may require less that 3 square kilometres of water to find enough food, whereas next to a small river, they may require a stretch of 30 kilometres or more. Some tend to move around to avoid the wettest weather, whereas others stay where they are all year round,