A short tail and huge wings enable it to glide and soar easily, which it does with its head stretched forward. The crest on the back of the head mirrors the stout beak and produces the hammerhead shape from which the species takes its name. Shallow fresh water, lakes, ponds, swamps and marshes. Hammerkops feed on frogs, fish and invertebrates. A sedentary species which remains in a well-defined territory, although some pairs will move to normally dry areas when the seasonal rains fill dry holes and ditches.
Hammerheads are also to be seen in group ceremonies, usually near a nest.
As many as ten birds may call loudly while running round each other in circles, a male sometimes mounting a crouching female and pretending to copulate. Crests are raised, wings fluttered and a chorus of cries continues for several minutes. True mating is usually done at the nest site, using displays similar to those used during larger gatherings. The young make their first flight at about 7 weeks but may return nightly for up to a month thereafter to roost in the nest. They build huge, domed nests which are among the most extraordinary constructions in the bird world.