Antarctic Sheathbill

Photograph By: Jeff Otten, National Science Foundation

 

Description & Characteristics:

Sheathbills are found all around the rocky shorelines of the Antarctic Peninsula and sub-antarctic islands. Unlike true seabirds that are able to swim and fish for food, sheathbills' feet are not webbed. They are more suited to scavenging food from other birds for which they are notorious. In a sense, they are the garbage collectors of the Antarctic. One has only to witness one of these odd birds strutting and squabbling around a penguin colony to confirm their opportunistic nature. Sealers called sheathbills 'paddies' because of their skills at theft; an insult to both the Irish and the birds. The were also known as 'sore-eyed pigeons,' or the more modern interpretation: "hens with attitude" which upon seeing them seems an appropriate name.

Lesser or Black-faced sheathbills are strict residents of the four sub-Antarctic island groups of the South Indian Ocean, each island group with its own subspecies. Some populations of Lesser sheathbills are on the decrease, possible due to competition with introduced species such as mice and rats. The Snowy sheathbills are somewhat larger, with noticeably longer wings, and occur at South Georgia Island, the South Shetlands, the South Orkneys and on the Antarctic Peninsula. They usually stay out of the path of the sea-ice and move north to South America and the Falklands in the winter when the worst weather comes. There are no known conservation problems for this species at the current time.

Sheathbills nest in rocky crevices in summer, usually near penguin colonies, where the scavenging is best and where they seem to have no fear. On occasion, they have been observed to disturb adult penguins to the point of successfully stealing food right from the mouths of feeding chicks. This is typically accomplished by the focal bird when it strategically displaces the chick before the parent finishes complete regurgitation. Food is dropped onto the ground and the result is a happy sheathbill and a hungry penguin chick.

  Did you know?


- Sheathbills are the only Antarctic bird species lacking webbed feet and thus must scavenge for food, as they cannot fish like other birds.

- Sheathbills nest near penguin colonies, where they feast widely on eggs, leftover scraps from chick-feeding, carcasses killed by Giant petrels, and even feces.

- Amazingly hardy creatures, sheathbills can tolerate extremes of temperature by fluffing their feathers for increased insulation.