Until recently the shearwaters were devided in two genera Calonectris and Puffinus, but based on dna-analysis Penhallurick and Wink (2004) have proposed a splitting of the shearwaters into three genera: Calonectris for the large shearwaters of the Northern Atlantic, the Mediterranean and the waters around Japan, Ardenna for a group of large Southern Hemisphere breeders and Puffinus for the smaller shearwaters such as the Manx’ group, Audubon’s and Little Shearwaters. This new taxonomy is now widely accepted, but not by all and is stil subject of discussion.
Listen to the sound of Black-vented Shearwater
Copyright remark: Most sounds derived from xeno-canto
|wingspan min.:||80||cm||wingspan max.:||85||cm|
|size min.:||34||cm||size max.:||36||cm|
|incubation min.:||48||days||incubation max.:||50||days|
|fledging min.:||68||days||fledging max.:||70||days|
arwaters, over continental shelf within a few miles of the coast. Favors warm waters at all seasons: fewer move north along California coast in years when sea surface temperature is lower. Nests on islands with enough soil for burrowing or with natural cr
evices in rock.
Nest: Site is in burrow in ground, sometimes in natural crevice in rock. Burrow may be more than 10′ long, often with turns to the
side rather than straight; probably both sexes help dig burrow, as in related species. Nest chamber at end of burrow may have a few bits of plant material or may be unlined.
Clutch 1. Dull white. Incubation probably by both sexes, as in other shearwaters; incubation period not well known.
Young: Both parents probably feed young, by regurgitation. Development of young and age at first flight not well known, but young probably remains in nest at least 2 months.
Behavior: Forages by seizing items at or just below surface
while swimming, by plunging into water from low flight, or by making shallow dives from surface. Apparently does not dive as often nor swim as well underwater as the similar Manx Shearwater.
Video Black-vented Shearwater
copyright: Peter Fraser
Breeds on sea islands off Pacific Coast
of Baja California. Migration:
Moves north from Baja into California’s coastal waters in fall. Numbers and timing variable: when sea temperature is high, may arrive early and in large numbers. Some also may move well to south of breeding range, but southward migration poorly known.