The Atlantic petrel (''Pterodroma incerta'') is a

gadfly petrel The gadfly petrels or ''Pterodroma'' are a genus of about 35 species of petrels, part of the seabird order Procellariiformes. The gadfly petrels are named for their speedy weaving flight, as if evading gadflies (horse-fly, horseflies). The flight ...

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the South

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

. It breeds in enormous

colonies A colony is a territory subject to a form of foreign rule, which rules the territory and its indigenous peoples separated from the foreign rulers, the colonizer, and their '' metropole'' (or "mother country"). This separated rule was often or ...

Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcano, volcanic islands in the South Atlantic Ocean. It is one of three constituent parts of the British Overseas Territories, British Overseas Territory of Saint Helena, Ascensi ...

and

Gough Island Gough Island ( ), also known historically as Gonçalo Álvares, is a rugged volcanic island in the South Atlantic Ocean. It is a dependency of Tristan da Cunha and part of the British overseas territory of Saint Helena, Ascension and Tristan d ...

, and ranges at sea from

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

, 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.

Population trends

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 The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

. It is restricted to just two breeding islands and has declined historically due to exploitation for food. According to some studies, there are roughly 1.1 million mating pairs, but only about 25% of eggs survived. This is making their large population numbers decrease rapidly.

was the location of study, since other islands are inaccessible due to the steep cliffs. Due to reproduction mortality, this species can become locally

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

making their home range smaller.

Habitat and ecology

The species feeds mostly on

squid A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also ...

, which comprise 87% of its diet in some studies; it will also feed on

lanternfish Lanternfish (or myctophids, from the Greek language, Greek μυκτήρ ''myktḗr'', "nose" and ''ophis'', "serpent") are small mesopelagic fish of the large family (biology), family Myctophidae. One of two families in the order Myctophiformes, ...

es (Myctophidae) as they ascend to the surface at night, as well as on

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

and some fish. This species is known for its nocturnal breeding habits. The nesting locations are between 50 and 300 meters above sea level, located on cliffsides on

and formerly, at

it was upwards of 700 meters. It nests in burrows dug in peaty soils in fern-bush vegetation.

Predators and threats

The Atlantic petrel is currently threatened by introduced

house mice The house mouse (''Mus musculus'') is a small mammal of the rodent family Muridae, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus '' Mus''. A ...

, which prey on recently-hatched chicks. Mouse predation is particularly prevalent on Gough Island, whose mice have rapidly evolved to be about twice the size of their mainland counterparts through a phenomenon commonly known as

island syndrome Island syndrome describes the differences in Morphology (biology), morphology, ecology, physiology and ethology, behaviour of island, insular species compared to their continental counterparts. These differences evolve due to the different evolut ...

. Given their small breeding range, severe hurricanes also pose an intermittent threat to breeding populations. Increasingly severe storms also threaten the availability and predictability of food sources such as squid.

Conservation efforts

Starting around the 1970s, on

, they have programs to teach and learn about this species and why it is important for the ecosystem. They also educate about the dangers that the birds are facing and research ways to implement protection for them in the future. Considering their populations numbers are high, their declining population is thought to be due to the mortality rate of eggs and young.

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 The house mouse (''Mus musculus'') is a small mammal of the rodent family Muridae, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus '' Mus''. A ...

is important to finding ways in reducing these predators' effect on the Atlantic Petrels.

Proposed actions

Further studies on the

house mouse The house mouse (''Mus musculus'') is a small mammal of the rodent family Muridae, characteristically having a pointed snout, large rounded ears, and a long and almost hairless tail. It is one of the most abundant species of the genus '' Mus''. A ...

have focused on ways to eradicate mice on

, minimizing the risk of introducing other invasive species, and finding methods better to understand the Atlantic petrel's habits. Demographic mapping is being used to better understand the island and its animal population trends. The petrel was formerly classified as a

vulnerable species A vulnerable species is a species which has been Conservation status, categorized by the International Union for Conservation of Nature as being threatened species, threatened with extinction unless the circumstances that are threatened species, ...

by the

. However, new research revealed the severe impact of predation by mice, and the species was uplisted to

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

in 2008.BLI (2008a,b)

Footnotes

References

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding i ...

(BLI) (2008a)
2008 IUCN Redlist status changes.
Retrieved 2008-MAY-23. *

(BLI) (2008b)
Atlantic Petrel Species Factsheet
Retrieved 2008-MAY-23. * Enticott, J.W. (1991): Distribution of the Atlantic Petrel ''Pterodroma incerta'' at sea. ''Marine Ornithology'' 19(1): 49–60
PDF fulltext
* Klages, N.T.W. & Cooper, J. (1997) Diet of the Atlantic Petrel ''Pterodroma incerta'' during breeding season at South Atlantic Gough Island. ''Marine Ornithology'' 25(1+2): 13–16
PDF fulltext
{{Taxonbar, from=Q780365 Gadfly petrels Pterodroma Birds of the Atlantic Ocean Birds of Argentina Birds of Brazil Fauna of Gough Island Birds of Southern Africa Birds of islands of the Atlantic Ocean Birds of subantarctic islands Birds of Uruguay Endangered fauna of Africa Endangered fauna of South America Birds described in 1863 Species that are or were threatened by invasive species Endemic birds of Saint Helena, Ascension and Tristan da Cunha