The snowy sheathbill (''Chionis albus''), also known as the greater sheathbill, pale-faced sheathbill, and paddy, is one of two species of

sheathbill The sheathbills are a family of birds, Chionidae. Classified in the wader order Charadriiformes, the family consists of one genus, ''Chionis'' with two species. They breed on subantarctic islands and the Antarctic Peninsula, and the snowy sheath ...

. It is usually found on the ground. It is the only land bird native to the Antarctic continent.

Taxonomy

The snowy sheathbill was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

's '' Systema Naturae''. He placed it in a new

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Vaginalis'' and coined the binomial name ''Vaginalis alba''. Gmelin based his description on the "white sheath-bill" that had been described and illustrated in 1785 by the English ornithologist John Latham in his ''A General Synopsis of Birds ''. Latham erroneously believed that the bird was found in New Zealand. The type locality was designated as the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...

Baron Bradford Baron is a rank of nobility or title of honour, often hereditary, in various European countries, either current or historical. The female equivalent is baroness. Typically, the title denotes an aristocrat who ranks higher than a lord or knig ...

and Charles Chubb in 1912. The snowy sheathbill is now placed in the genus ''

Chionis The sheathbills are a family of birds, Chionidae. Classified in the wader order Charadriiformes, the family consists of one genus, ''Chionis'' with two species. They breed on subantarctic islands and the Antarctic Peninsula, and the snowy sheat ...

'' that was introduced in 1788 by the German naturalist

Johann Reinhold Forster Johann Reinhold Forster (22 October 1729 – 9 December 1798) was a German Reformed (Calvinist) pastor and naturalist of partially Scottish descent who made contributions to the early ornithology of Europe and North America. He is best known ...

. The genus name is from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

''khiōn'' meaning snow. The specific epithet ''albus'' is

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

meaning "white". The species is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

: no subspecies are recognised.

Description

A snowy sheathbill is about long, with a wingspan of . It is pure white except for its pink, warty face; its Latin name translates to "snow white". Sheathbills spend 86% of their day hunting for food and the other 14% resting.

Distribution and habitat

The snowy sheathbill lives in

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest cont ...

, the

Scotia Arc The Scotia Arc is the island arc system forming the north, east and south border of the Scotia Sea. The northern border, the North Scotia Ridge, comprises (from west to east) Isla de los Estados at the tip of Tierra del Fuego, the Burdwood, Davis, ...

, the

South Orkneys The South Orkney Islands are a group of islands in the Southern Ocean, about north-east of the tip of the Antarctic PeninsulaSouth Georgia. Snowy sheathbills living very far south migrate north in winter.

Feeding

The snowy sheathbill does not have webbed feet. It finds its food on land. It is an omnivore, a scavenger, and a

kleptoparasite Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when foo ...

and will eat nearly anything. It steals regurgitated krill and fish from penguins when feeding their chicks and will eat their eggs and chicks if given the opportunity. Sheathbills also eat carrion, animal feces, and, where available, human waste. It has been known to eat

tapeworm Eucestoda, commonly referred to as tapeworms, is the larger of the two subclasses of flatworms in the class Cestoda (the other subclass is Cestodaria). Larvae have six posterior hooks on the scolex (head), in contrast to the ten-hooked Cesto ...

s that have been living in a chinstrap penguin's intestine. Sheathbills that are actively hunting for food spend approximately 38% of the day hunting, 20% of the time eating their prey, 23% just resting, 14% doing various comfortable activities, and the final 3% will be towards agonistic behavior.

Gallery

Image:Flying sheathbill.jpg, Flying sheathbill Image:2019-03-03 165 Snowy sheathbill (Chionis albus), Barrientos Island, Antarctica.jpg, This snowy sheathbill is watched carefully by a chinstrap penguin, as they are predators of penguin chicks and eggs Image:Pochwodziob (js).jpg, Eating regurgitated penguin chick food Image:Snowy Sheathbill walks by an Antarctic Fur Seal (5893495431).jpg, Snowy sheathbill walks by an Antarctic fur seal, at Cooper Bay, South Georgia Image:2019-03-03 159 Snowy sheathbill (Chionis albus), Barrientos Island, Antarctica.jpg, Adult snowy sheathbill, on Barrientos Island

References

Birds of Antarctica

snowy sheathbill The snowy sheathbill (''Chionis albus''), also known as the greater sheathbill, pale-faced sheathbill, and paddy, is one of two species of sheathbill. It is usually found on the ground. It is the only land bird native to the Antarctic continent. ...

Birds of islands of the Atlantic Ocean Birds of subantarctic islands Graham Land

{{Charadriiformes-stub