The Cape Verde shearwater (Calonectris edwardsii), or cagarra locally, is a medium-large shearwater, a seabird in the petrel family Procellariidae. It is endemic to the Cape Verde archipelago of Macaronesia in the Atlantic Ocean, off the coast of West Africa.
Taxonomy
The Cape Verde shearwater was originally described in 1883 by Émile Oustalet as a full species. It was later lumped as a subspecies of Cory's shearwater but has since been separated again, by Cornelis Hazevoet in 1995, as a distinct species.
Description
The Cape Verde shearwater has a slim, dark bill, with head and upperparts darker than Cory's. The flight is more typically shearwater-like than Cory's, with stiffer and more rapid wing beats. The overall appearance, compared with Cory's, is of a smaller, slimmer and more angular bird.
Distribution
The shearwaters breed only within the Cape Verde Islands. The largest colonies are on the islands of Brava, Branco and Raso, though the species also breeds in smaller numbers on other islands in the archipelago. Individuals have been found offshore of Maryland and North Carolina.
Behaviour
Breeding
Following a three-month absence, the mature birds arrive at their island breeding colonies in late February and March, where they nest in cliff hollows, on offshore rocks, and under large boulders. Females lay a single egg and incubation takes place from May to July, with the chicks fledging from late September to November. Following fledging, all birds stay at sea until the next breeding season. Numbers have declined because of over-harvesting of young birds and the species is considered to be near threatened.
References
External links
- Magikbirds: Cape Verde shearwater
- New England Seabirds: Cory's shearwater complex
- Avibase: Cape Verde shearwater
- ARKive: Cape Verde shearwater