The Marabou stork (Leptoptilos crumeniferus) is a large wading bird in the stork family Ciconiidae. It breeds in Africa south of the Sahara, in both wet and arid habitats, often near human habitation, especially waste tips. It is sometimes called the "undertaker bird" due to its shape from behind: cloak-like wings and back, skinny white legs, and sometimes a large white mass of "hair".
This skull cast from a Leptoptilos crumeniferus displays its long beak. The marabou stork is a massive bird: large specimens are thought to reach a height of 60 in and a weight of 20 lb. A wingspan of 12 ft was accepted by Fisher and Peterson, who ranked the species as having the largest wing-spread of any living bird. Even higher measurements of up to 13.3 ft have been reported, although no measurement over 10.5 ft has been verified. It is often credited with the largest spread of any landbird, to rival the Andean condor; more typically, however, these storks measure 7–9 ft across the wings, which is about a foot less than the average Andean condor wingspan and nearly two feet less than the average of the largest albatrosses and pelicans.
The marabou is unmistakable due to its size, bare head and neck, black back, and white underparts. It has a huge bill, a pink gular sac at its throat, a neck ruff, and black legs and wings. The sexes are alike, but the young bird is browner and has a smaller bill. Full maturity is not reached for up to four years.
Like most storks, the marabou is gregarious and a colonial breeder. In the African dry season (when food is more readily available as the pools shrink) it builds a tree nest in which two or three eggs are laid.
It also resembles other storks in that it is not very vocal, but indulges in bill-rattling courtship displays. The throat sac is also used to make various noises at that time.
The marabou stork is a frequent scavenger, and the naked head and neck are adaptations to this livelihood, as it is with the vultures with which the stork often feeds. In both cases, a feathered head would become rapidly clotted with blood and other substances when the bird's head was inside a large corpse, and the bare head is easier to keep clean.
The name Marabou is thought to be derived from the Arabic word murābit meaning quiet or hermit-like.