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.
In calm weather, Sooty Shearwaters fly low over the ocean’s surface with quick, stiff wing-beats. On windy days, they glide over the waves. They are often found in groups of hundreds or thousands, flying in long lines or grouped tightly together on the water. They plunge into the water from a few feet above the surface and swim under water, using their wings to propel themselves. They also dive from the surface, taking prey at surface level, or just below. They sometimes feed near dolphins, whales, or other seabirds.
Listen to the sound of Sooty Shearwater
Copyright remark: Most sounds derived from xeno-canto
recorded by Ryan Merrill
|wingspan min.:||95||cm||wingspan max.:||110||cm|
|size min.:||40||cm||size max.:||50||cm|
|incubation min.:||52||days||incubation max.:||57||days|
|fledging min.:||86||days||fledging max.:||57||days|
Video Sooty Shearwater
Puffinus griseus breeds on subantarctic islands in the Southern Ocean, migrating to the temperate zones of the North Atlantic and North Pacific during its non-breeding season (the boreal summer). It occurs mainly off the North American coast during
the first half of the non-breeding season, and is only present in significant numbers in European waters during (and just prior to) its southern passage (mainly in August- October).
While some non-breeders are present off the Pacific Coast in all seasons, the breeding adults head north in April and May, on their way to the north Pacific where they spend the non-breeding season. The migration occurs in waves of age classes, with the sub-adults moving in the first wave, breeding adults next, and finally the non-breeding adults and fledglings last.
Northward movements begin late March but mostly April-May. Following rapid northward, transequatorial migration up west Atlantic, first arrivals off North American coasts in April and early May, exceptionally March; still largely concentrated off New England and Newfoundland area in June (very few European records then); begins spreading across temperate North Atlantic in July.
Numbers begin decreasing in western North Atlantic in August, when return passage has begun. Others, however, apparently move east since more mid-ocean records in August-September; and then becomes more widespread off north-west European coasts (usually well offshore) including concentrations on Rockall Bank and Faeroese fishing grounds. At same time, southerly movements occur off east Atlantic seaboard south to Morocco, and to lesser extent in North Sea and English Channel. Many fewer North Atlantic flocks in October, and only stragglers November-March.