Hamerkop

Hamerkops eat frogs and tadpoles.

They eat small fish and bugs too.

Hamerkops eat mostly frogs, tadpoles and small fish. They also eat crustaceans (animals such as crabs and shrimp), worms and insects. They hunt in shallow water, along sandbanks, in reeds and among floating plants.

A hamerkop may stir the water with its feet or flap its wings to startle its prey. It can also catch fish while flying, gliding over open water and dipping down to grab one.

The IUCN gives a diet mainly of amphibians, especially clawed frogs (Xenopus) as adults and tadpoles, and small fish, plus crustaceans, worms and insects (del Hoyo et al. 1992); the Roger Williams Park Zoo adds small mammals. It forages in shallow water along sandbanks, in reedbeds or in floating vegetation (Brown et al. 1982).

The Maryland Zoo describes stirring the water with the feet or flapping the wings to startle prey, and feeding on the wing by gliding over open water and dipping to seize fish. It adds that hamerkops are often robbed of their catch by bigger birds such as the fish eagle.

Hamerkops often live in pairs.

Sometimes they meet in a group, call loudly and run in circles.

Hamerkops usually live in pairs and stay in their own area. Outside the nesting season, small groups of about 8 to 10 may gather, and sometimes more than 50.

Before nesting, hamerkops may gather near nest sites. Many call at once while running around each other in circles, with crests raised and wings fluttering. Their big nests are useful to other animals too: owls, kestrels, geese, ducks and pigeons may move into them.

Outside the breeding season hamerkops usually occur in pairs or small groups of 8 to 10, sometimes in social groups of more than 50 (IUCN, after Brown et al. 1982); the Maryland Zoo notes well-defined territories that the birds rarely leave. Group courtship displays involve many birds calling together while running around each other with crests raised and wings fluttering; mounting during these displays is only ceremonial, and real mating happens while a pair builds its nest (Maryland Zoo).

The nests attract other animals. The Maryland Zoo lists Verreaux's eagle-owls, gray kestrels and barn owls that may take nests over, genets that may live in them, weavers, mynas and pigeons that attach their own nests, and Egyptian geese, pygmy geese and knob-billed ducks that use old nests. Monitor lizards and snakes often raid the nests to take eggs (Maryland Zoo).

There are lots of hamerkops.

Too many farm chemicals in the water could harm the places where they feed.

The hamerkop is listed as least concern. There may be about 113,000 to 743,000 adult hamerkops, and scientists do not know whether their numbers are going up or down.

Too many pesticides in the water could harm the wetlands where hamerkops feed. In Nigeria, some hamerkops are hunted and sold at markets.

BirdLife International assessed Scopus umbretta as Least Concern for the IUCN Red List (assessed 22 July 2024, published 2025): extremely large range, population trend unknown but not thought to be declining fast enough to approach the thresholds, about 170,000 to 1,115,000 individuals (Wetlands International 2023), equal to 113,000 to 743,000 mature birds. Generation length is 6.03 years.

The IUCN names one potential threat, wetland water quality made worse by excessive pesticide use (del Hoyo et al. 1992), and notes that hamerkops are hunted and traded at markets in Nigeria (Nikolaus 2001). It was found in three of seven trade datasets reviewed by Donald et al. (2024). The species occurs in at least one protected area.