As well as around 300 islanders, this mountainous archipelago is home to millions of pairs of seabirds, and several unique land birds. It includes the World Heritage Site of Gough and Inaccesible Islands: Gough is arguably the most important seabird island in the world.
Unfortunately, albatrosses and petrels, including three species which nest nowhere else, fall frequent victim to longline fishing. On the islands themselves is a far more insidious threat. Rats and mice reached the archipelago on board boats. The chicks of petrels and albatrosses have evolved on islands with no terrestrial mammals and have no defences when such predators arrive.
Rats have destroyed many great seabird colonies around the world, after introduction by humans. On the main island of Tristan da Cunha the once vast colonies of petrels are now reduced to tiny remnants. On Gough Island, researchers have discovered that Gough’s house mice have learned to attack and kill seabird chicks, even huge Tristan albatross chicks. This predation is widespread and devastating. Tristan albatrosses and Atlantic petrels are declining fast.
Fortunately, two other islands (Nightingale and Inaccessible) remain rodent-free and it is vital they remain so – they are havens for seabirds and endemic land birds such as the rarest “British” bird, the Wilkins’ bunting which is found only on Nightingale, and the world’s smallest flightless bird, the Inaccessible rail.
Species affected (not UK birds)
Tristan albatross, Gough bunting, Gough moorhen, Atlantic yellow-nosed albatross, spectacled petrel, Tristan thrush, Inaccessible bunting, Wilkins’ bunting, sooty albatross, Atlantic petrel