Hamerkop

The hamerkop (Scopus umbretta) has a number of alternative names, including hammerhead stork, umbrette, tufted umber and anvilhead. It is the only member of the Scopus genus and Scopidae family, although it has posed a problem over whether this family should be classed with the order of Ciconiformes (which includes storks) or Pelecaniformes (which includes pelicans and herons).

The hamerkop shows some stork-like features, such as flying with its neck extended and its lack of powder down, but its voice organs are heron-like and it has teeth on the outer edge of its middle claw, which is again a heron-like feature. The consensus appears to be that the hamerkop represents one of the missing links between storks and herons, so its status in terms of order remains in doubt.

The hamerkop is a wading bird that is found in many parts of tropical Africa, Madagascar and southwest Arabia. It inhabits wetlands that include rice paddies, irrigation ditches or roadside pools, and will migrate locally as suitable environments appear and disappear.

Hamerkops have gained a measure of protection from the superstitions and legends that have arisen about them in some parts of their range. It is widely believed, for example, that harming a hamerkop will bring bad luck. To the bushmen of the Kalahari region, the hamerkop is the “lightning bird”, and robbing a hamerkop nest will increase one’s chance of being struck by lightning.

Appearance and behaviour

The hamerkop is about 20 inches long and resembles a heron in its overall shape, but with comparatively shorter legs. It is brownish in colour with glossy purplish tinges on the wings and back. Its large head is set on a somewhat short and thick neck. The long, flat and slightly hooked bill, coupled with the prominent crest on the back of the head, give the bird its name, as the head is not unlike the shape of the head of a hammer (hamer kop is Afrikaans for “hammer head”). 

The hamerkop behaves in rather peculiar ways from time to time. A small group may dance around each other for no obvious reason, calling loudly, before they appear to bow to each other, pull their heads back and resume standing silently apart. 

Hamerkops have a varied diet, including water insects, worms, molluscs, small fish and amphibians. They are often most active in the evenings and can also be nocturnal.

Breeding

The hamerkop’s most remarkable feature is its compulsive nest building, which even takes place outside the breeding season. The nest is a vast structure, as much as six feet in diameter, that is a flattened covered dome with a side entrance. A pair of hamerkops can spend several months building a nest, which can comprise as many as 10,000 sticks in its construction, and when it is finished they may start work on another. Great care is taken in decorating the outside of a nest with objects found by the birds, much as a magpie might do to the inside, these items being anything that is highly coloured and takes the birds’ fancy.

When breeding, the female hamerkop will lay three to six eggs deep inside the nest and both partners will incubate them in turn for up to 30 days. Both parents will feed the nestlings, who can be left alone for long periods while the parents look for food, secure in the knowledge that the fortress-like nest provides excellent protection. The young birds are ready to leave the nest at around 50 days but will continue to roost in it for several months longer.

Unused hamerkop nests are often taken over by other bird and animal species, including snakes, and sometimes a bird such as an eagle owl will eject a hamerkop pair from their nest, only for them to return when the squatter has finished with it. 

© John Welford