South Georgia Pipit
The South Georgia Pipit (Anthus antarcticus) are the only land birds or passerines (perching birds) breeding in South Georgia and the Antarctic. Although the South Georgia pipit’s weight is similar to other pipits, it has developed thicker plumage to cope with the more extreme conditions. The breeding population was restricted by rat predation to offshore islands and rat-free sections of the mainland until 2015. When breeding, male pipits sing a lark-like song. These pipits and their abandoned nest and eggs came from the British Antarctic Survey base at Bird Island, where they died of natural causes.
Rats have been a large and important problem on island of South Georgia. They were introduced by whalers and sealers after 1775 when Captain Cook first landed on the island (there are no natural land mammals on South Georgia). Rats stowed away on the ships and found a plentiful supply of food by preying on birds’ eggs and young chicks, insects, tussac root and beach detritus. Rats dramatically reduced the bird populations of the smaller species and threatened some species with extinction. An example of this is the endemic South Georgia Pipit, this bird was not found in rat infested areas on the island but forced out of coastline areas by the Norwegian rat population, which ate the eggs and young in their nests or burrows.
After being eradicated by the South Georgia Heritage Trust Habitat Restoration Project by 2015, it has not taken long for birds to return to areas. The level of biosecurity on South Georgia is now receiving even greater attention from South Georgia government, to ensure that rats are not re-introduced by visiting ships and that other invasive plants and animals such as mice do not create a new issue.