The black-vented shearwater (''Puffinus opisthomelas'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

. The

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

is 30–38 cm in length with a 76–89 cm wingspan. Formerly considered a

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of the

Manx shearwater The Manx shearwater (''Puffinus puffinus'') is a medium-sized shearwater in the seabird family Procellariidae. The scientific name of this species records a name shift: Manx shearwaters were called Manks puffins in the 17th century. Puffin is an ...

, its actual taxonomic relationships are unresolved. This species is

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or wa ...

, occurring in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

and the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja Ca ...

. It comes closer to land than most other

shearwater Shearwaters are medium-sized long-winged seabirds in the petrel family Procellariidae The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the diving petrels, the prions, and the shearwa ...

s, so it can sometimes be seen from shore.E.g. "thousands upon thousands" of birds seen off

San Quintín, Baja California San Quintín is a city in San Quintín Municipality, Baja California, located on the Pacific Coast of Mexico. The city had a population of 4777 in 2011. San Quintín is an important agricultural center for Baja California. The city is also an eme ...

at the end of June: Thayer & Bangs (1908) It nests predominantly on offshore islands off north and western

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

, namely

Isla Natividad Isla Natividad is an island in the Pacific Ocean 6 km west off Punta Eugenia, the northwestern headland of the Mexican state of Baja California Sur. 200 meters off its northwestern end lies Roca María at , with an area of 0.074 km2 ...

(ca. 95% of the nesting population),

Isla de Guadalupe Guadalupe Island ( es, Isla Guadalupe, link=no) is a volcanic island located off the western coast of Mexico's Baja California Peninsula and about southwest of the city of Ensenada in the state of Baja California, in the Pacific Ocean. The ...

, and

Islas San Benito The Islas San Benito lie in the Pacific Ocean off the west coast of the Mexican state of Baja California, 25 km west of Cedros Island. They are part of the Cedros Island ''delegación'', a subdivision of Ensenada (municipality), Baja Califo ...

. It is fairly common off the United States

coast The coast, also known as the coastline or seashore, is defined as the area where land meets the ocean, or as a line that forms the boundary between the land and the coastline. The Earth has around of coastline. Coasts are important zones in n ...

of central and southern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

during the country's colder months. The black-vented shearwater is thought to feed on mainly small

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

. This bird nests in burrows and

caves A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

; it is a colonial nester. In the past, this bird had been threatened by

feral cat A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...

s and other predators on its breeding islands, but the problem seems to have been largely eliminated. There is some loss of birds from commercial

gill net Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is ...

ting, and the species is classified as

near threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

mainly due to the uncertain impact on it by the expanding fishing industry.

References

External links

Black-vented shearwater photos
– VIREO * ttp://www.southwestbirders.com/SD010106/bvsh_sd010106_web.JPG Photo-High Res– southwestbirders

black-vented shearwater The black-vented shearwater (''Puffinus opisthomelas'') is a species of seabird. The bird is 30–38 cm in length with a 76–89 cm wingspan. Formerly considered a subspecies of the Manx shearwater, its actual taxonomic relationship ...

Western North American coastal fauna Birds of Mexico Native birds of the West Coast of the United States Endemic birds of Southwestern North America

{{Procellariiformes-stub

References

Further reading

External links