Yellow-billed storks are not normally regarded as gregarious birds, and usually tend to solitude, being found singly or in pairs at the edges of dams, rivers and other areas of shallow marshy water. However, on a visit to a series of large dams near the Zambezi River, quite close to Katima Mulilo in Namibia, we found them to be present in large flocks, standing almost shoulder to shoulder as they hunted for food in the shallow water, No doubt this unusual sight was brought about by an abundance of food in the area, as the dams were also populated by vast numbers of other wading birds.
The Yellow-billed stork is a large bird, reaching about a metre in length, and the sexes are similar in both plumage and size. They are predominantly white in colour, with black edging to their wings and tails. Their bills are bright yellow, and their facial skin, legs and feet are red. A conspicuous bird that is not likely to be confused with any other species, In flight their necks are outstretched in typical stork fashion and their legs trail well behind their tail feathers.
Although they feed mainly on fish, Yellow-billed storks also eat frogs, worms, crustaceans and insects. They move very slowly and deliberately when feeding and spend long periods of time standing very still. They are well adapted to fishing and have very quick reflexes; they will often stir up the surface mud with one foot in order to disturb their prey, and when a likely morsel moves they are able to snap it up in their slightly decurved beaks.
They are usually silent birds, although during breeding they may give vent to a series of squeaky calls and hissing sounds.
In southern Africa there are both resident and migrant populations of Yellow-billed storks, with the migrants arriving around October and leaving again around April. The migrants do not breed in this region, but the resident birds are monogamous and generally nest colonially in heronries with other wading birds. They build a large nest of sticks in a tree, usually over the water or very close to it. The female lays a clutch of two to four dull white eggs that hatch after an incubation period of approximately 30 days.
The scientific binomial for the Yellow-billed stork is Mycteria ibis; Mycteria from the Greek for “a nose” and ibis from the Greek for an “ibis”. Thus we have an ibis with a nose! Good grief, how do they come up with these names?