Medium-billed prion
Salvin's prion (Pachyptila salvini ), also known as the medium-billed prion, is a species of seabird in the petrel family Procellariidae.
The name Pachyptila comes from the Greek words pakhus and ptilon. Pakhus means "thick" or "stout" and ptilon means "a feather". Also from the Greek language, prion comes from the word priōn meaning "a saw", which is in reference to its serrated edges of its bill. The species is named for the British ornithologist Osbert Salvin.
Salvin's prion is a small 29 cm (11 in) petrel with grey and white plumage, and a blue bill. Like the broad-billed prion it has lamellae in its bill in order to filter seawater for food.
Salvin's prion breeds principally on Île aux Cochons in the Crozet Islands, where four million pairs are thought to breed. Other breeding colonies include Prince Edward Island, St Paul Island and Amsterdam Island. At sea they range from South Africa eastwards to New Zealand.
The main components of its diet are amphipods and krill, although it will also take fish and squid. In addition to filter feeding, food is obtained by seizing and hydroplaning.
This small prion breeds colonially on a number of subantarctic islands in the southern Indian Ocean. The colonies of medium-billed prions are attended nocturnally in order to avoid predation by skuas. The nests are concealed in burrows usually dug into soil. Nests are attended regularly for several months prior to breeding. A single egg is laid in November or early December, which is incubated for around 50 days. Both parents share the incubation duties and feed the chick once it is hatched. The chicks fledge around 60 days after hatching.
Salvin's prion is not considered threatened with extinction. Although numbers have declined on some islands where rats and feral cats have been introduced, the world population is estimated at around 12 million birds. Consequently, they are given a classification of Least Concern.
