African Openbill

The African openbill, Anastomus lamelligerus, is a medium-sized stork with a distinctive bill that is adapted to its diet. Adults measure between 80–94 cm in length and weigh 1–1.3 kg. The species shows little sexual dimorphism, though males are marginally larger with a more substantial bill. The adult's bill, brownish and measuring 135–196 mm, features a notable gap between the upper and lower mandibles, which is absent in juveniles but develops with age. The plumage of adults is predominantly black with a shimmering green sheen on their backs, coverts, and abdomens, while juveniles display a duller, browner coloration with paler tips on their underparts. Legs and feet are black, and the eyes are grey without distinct eye-ring coloration.

Identification Tips

When identifying the African openbill, look for the unique gap between the mandibles of the bill, which only meet at the tip. The iridescent green feathers on the back and the overall black plumage are also key characteristics. Juveniles are less vibrant and have brownish plumage with pale-tipped underparts.

Habitat

The African openbill is typically found in freshwater wetlands with nearby tall trees or shrubs for nesting. They inhabit environments where their preferred mollusc prey is abundant.

Distribution

This stork is widely distributed across Sub-Saharan Africa and western Madagascar. It has a patchy distribution but is considered common to locally abundant within its range.

Behaviour

The African openbill is an agile flier, capable of performing steep dives and acrobatic maneuvers. It can be seen foraging in shallow waters, often standing on the backs of hippopotamuses to access snails dislodged by the mammals. In flight, the neck and head are extended, and the broad wings are adept at soaring and gliding on air currents.

Song & Calls

Social displays are often accompanied by bill clatters, a common trait among Ciconiidae. The African openbill also emits croaks and honks loudly.

Breeding

Breeding seasons vary with location, timed to coincide with the emergence of snails. African openbills form monogamous pairs and nest in colonies, which can be mixed with other waterbirds. The nests are constructed in tall trees, and both parents share in the incubation and care of the young.

Similar Species

The closest relative to the African openbill is the Asian openbill (Anastomus oscitans), which shares the large and peculiarly shaped bill.

Diet and Feeding

The African openbill's diet is specialized, consisting primarily of aquatic snails and occasionally freshwater mussels, frogs, crabs, fish, worms, and large insects. They forage by wading in shallow water, using their bills to grasp and carry prey to shore for consumption. The species is adept at extracting mollusc meat without breaking the shells.

Conservation status

The IUCN lists the African openbill as Least Concern. While the species is not currently threatened, its large size and low reproductive success mean that habitat changes could significantly impact populations.