The shoebill (Balaeniceps rex) also known as whalehead, whale-headed stork, or shoe-billed stork, is a very...
The shoebill (Balaeniceps rex) also known as whalehead, whale-headed stork, or shoe-billed stork, is a very large stork-like bird. It derives its name from its enormous shoe-shaped bill. It has a somewhat stork-like overall form and has previously been classified with the storks in the order Ciconiiformes based on this morphology. However, genetic evidence places it with the Pelecaniformes. The adult is mainly grey while the juveniles are browner. It lives in tropical east Africa in large swamps from Sudan to Zambia.
Taxonomy and systematics
The shoebill was known to both ancient Egyptians and Arabs, but was not classified until the 19th century, after skins and eventually live specimens were brought to Europe. John Gould described it in 1850, giving it the name Balaeniceps rex. The genus name comes from the Latin words balaena "whale", and caput "head", abbreviated to -ceps in compound words.
Traditionally allied with the storks (Ciconiiformes), it was retained there in the Sibley-Ahlquist taxonomy which lumped a massive number of unrelated taxa into their "Ciconiiformes". More recently, the shoebill has been considered to be closer to the pelicans (based on anatomical comparisons) or the herons (based on biochemical evidence; Hagey et al., 2002). Microscopic analysis of eggshell structure by Konstantin Mikhailov in 1995 found that the eggshells of shoebills closely resembled those of other Pelecaniformes in having a covering of thick microglobular material over the crystalline shells. A recent DNA study reinforces their membership of the Pelecaniformes.
So far, two fossil relatives of the shoebill have been described: Goliathia from the early Oligocene of Egypt and Paludavis from the Early Miocene of the same country. It has been suggested that the enigmatic African fossil bird Eremopezus was a relative too, but the evidence for that is unconfirmed. All that is known of Eremopezus is that it was a very large, probably flightless bird with a flexible foot, allow