The Atlantic petrel (Pterodroma incerta ) is a gadfly petrel endemic to the South Atlantic Ocean. It breeds in enormous colonies on Tristan da Cunha and Gough Island, and ranges at sea from Brazil to Namibia, with most records at sea being to the west of the breeding islands, and along the subtropical convergence. Adults are about 43 cm long, powerful, large, stocky, dark in color with white belly. Their head can appear to be grey in worn plumage. Brown undercoating of wings and tail.. These petrels can live on average of 15 years of age.
The species feeds mostly on squid, which comprises 87% of its diet in some studies; it will also feed on lanternfishes (Myctophidae) as they ascend to the surface at night, as well as on crustaceans and some fish. This species is known to being nocturnal habits when feeding. The nesting locations are between 50 and 300 meters above sea level, located on cliffsides on Gough Island and formerly, at Tristan da Cunha it was upwards of 700 meters. It nests in burrows dug in peaty soils in fern-bush vegetation.
It is also currently thought to be threatened by introduced house mice, which attack the eggs generally within a 2-hour period of being hatched that is leading to low breeding success. Another threat to the Atlantic petrel is Hurricanes also known as a cyclone system, it has a severe impact on populations by displacing them from their habitat and breeding grounds. Feather mites that are affecting the bird's population on the Brazilian coast, the Microspalax atlanticus affect the feathers with mites. This species is affecting a wild variety of birds in Brazil, but it has a large impact on the Atlantic petrel have a declining reproduction rate.
Many birds died of starvation due to their food source like squid being altered from the intense hurricanes. This is another leading threat to their decline in population. Significant mortality rate is increasing as the storms intensities increase, largely in females.
Although the species exists in large numbers, the world population being estimated at around 5 million birds, it is listed as endangered by the IUCN. It is restricted to just two breeding islands and has declined historically due to exploitation for food. In some studies, only about 25% of eggs have hatched. Some studies states there are roughly 1.1 million mating pairs. This is making their large population numbers decrease rapidly. Gough Island has been the location of study, since a couple of other islands are inaccessible due to the steep cliffs. Due to reproduction mortality, this species can become locally extinct making their home range smaller.
Starting around the 1970s, on Tristan da Cunha they have put in programs to teach and learn about this species of bird and why it is important for the ecosystem. Also, they try and educate about the dangers that they are facing as a species and find out more ways to implement protection for them in the future. Considering their populations numbers are high, there mortality rate at birth is significant to have a declining population. Gough Island is a nature reserve and World Heritage site, there is a field station on this island to observe the Atlantic Petrels population. Research on the House mouse is important to finding ways in reducing these predators' effect on the Atlantic Petrels.
