Bird migration as they ride the "roaring forties" outside the breeding season. The tubenoses spread widely over large areas of open ocean, but congregate when food becomes available. Many are also among the longest-distance migrants; sooty shearwaters "Puffinus griseus" nesting on the Falkland Islands migrate between the breeding colony and the North Atlantic Ocean off Norway. Some Manx shearwaters "Puffinus puffinus" do this same journey in reverse. As they are long-lived birds, they may cover enormous distances during their lives; one record-breaking Manx shearwater is calculated to have flown 8 million km (5 million miles) during its over-50 year lifespan. Some large
Chagos Marine Protected Area Chagos are considered to be of international importance. The archipelago harbours eighteen different species of breeding birds and ten of its islands have been designated as Important Bird Areas (IBAs) by Birdlife International, making the region the most diverse breeding seabird community in this tropical region, though the presence of human-introduced rats on several of the other islands severely hinder seabird nesting on these. Five species are considered to be breeding in internationally significant numbers: the sooty tern ("Sterna fuscata"); the brown and lesser noddy ("Anous stolidus" and "Anous tenuirostris"); the red-footed booby ("Sula sula") and the wedge-tailed shearwater ("Puffinus