Charles Darwin in The Voyage of the Beagle.

Monotypic

Alternative names include King or New Zealand Muttonbird, Sombre Petrel or Sombre Shearwater.
 

Identification

A large solid bodied shearwater, quite similar to Short-tailed Shearwater. Dark-brown except for the pale underwing coverts which often show conspicuously as the bird banks. Flight action is strong with several rapid, stiff-winged beats followed by a long glide. In stronger winds, flight becomes faster with more dynamic banking and gliding. Will examine the wakes of ships for potential feeding opportunities. Partial albinism occurs with some regularity, presenting potential confusion with other species such as Cape Petrel

Check out Greg Gillison's web page discussing the separation of Sooty Shearwater from Short-tailed Shearwater, dark-phase Pacific Northern Fulmar and Flesh-footed Shearwater.

Figure 1 Dorsal view of a Sooty Shearwater photographed on 23 August 1999 during a Shearwater Journeys trip to the Cordell Bank, California. Still image taken from a digital video. Copyright of Angus Wilson© 1999
 

Where and When

Total world population in the tens of millions. Breeds on islands off Cape Horn and Tierra del Fuego; Chiloe, Guafo and Guamblim Islands; Kidney Island in the Falkland group; a number of islands off New South Wales, Australia from Broughton to Montagu Island and also off south east Tasmania; Macquarie Island; islands around New Zealand including Stewart Island, the Chatham Islands, The Snares (nearly 3 million prs), the Auckland Islands, the Antipodies Islands, and Campbell Island.

In the non-breeding season most move into the North Pacific and North Atlantic. Migrate in immense flocks. A few remain in the southern hemisphere all year, particularly off southern Africa, southern South America and southern Australia. Most adults depart the breeding grounds in the second week of April a few remaining into May. Chicks leave a month later. In Pacific, probably head directly for the Aleutians and Kurile Islands traveling in a broad front. South American breeders probably travel up the Humbolt Current reaching California in mid-May where they may remain in large numbers into September with many lingering to November. Tend not to enter the Bering Sea unlike Short-tailed Shearwater. Return to nesting burrows in mid to late September. Breeding birds forage less widely than Short-tailed Shearwater but still abundant near the edge of the Antarctic ice pack.

Figure 2 Sooty Shearwater, west of Bodega Head, California on 25 August 1999. Copyright of Angus Wilson© 1999
 

Photographs on the web

In flight and another in flight. Photos by Steve Shunk and posted on the Bird Guide pelagic site.

on the water and another on the water. Photos by Tim Shelmerdine and posted on the Bird Guide pelagic site.
 

Figure 3 Sooty Shearwater, west of Bodega Head, California on 25 August 1999. Notice the distribution of white on underwing primary coverts. Copyright of Angus Wilson© 1999

Figure 4 Beach-cast Sooty Shearwater, Monterey Bay, California on July 1998. Notice the distribution of white on underwing primary coverts. Copyright of Angus Wilson© 1998
 

Literature

Warham, J. (1964) Marked Sooty Shearwaters Puffinus griseus in the Northern Hemisphere. Ibis 106: p390-391.