Sooty Shearwater

Puffinus griseus

(c) Glen Tepke
  • PROCELLARIIDAE
  • Shearwaters, Fulmars, Petrels
  • Procellariiformes
  • Pardela Gris
  • Puffin fuligineux
Introduction

With flocks including tens of thousands of individuals, Sooty Shearwaters rank high on the social seabird scale. In windy weather these shearwaters glide effortlessly above the waves, sometimes flying in long lines or resting in dense rafts on the water. Sooty Shearwaters have made recent headlines for their spectacular long-distance migration. Recent tagging experiments have shown that birds breeding in New Zealand may travel to Japan, Alaska and California, and back—a total of 40,000 miles per year.

(c) Glen Tepke
Appearance Description
Sooty Shearwaters average 17 inches in length, with a wingspan of 40 inches, and weigh 1.7 pounds. In good light, this relatively large shearwater shows the uniformly dark chocolate-brown plumage which is responsible for its name. The bird's long, narrow dark wings sport distinctive silvery under-wing coverts, and the bill is relatively long and dark, compared with similar shearwaters.
Range Map
Courtesy Kenn Kaufman
Range Distribution
Although the Sooty Shearwater is at times the most abundant bird off the California coast, it nests only in Australia, New Zealand, and southern South America. New Zealand has by far the most birds, with five million pairs in 80 breeding colonies—approximately half the world's population. Colonies on the Snares Islands south of New Zealand alone contain 2,750,000 pairs.
Habitat
Sooty Shearwaters generally concentrate around upwellings over cooler waters, or where cool and warm waters meet. They may feed close to shore in areas where the water is deep. They breed on isolated southern ocean islands that have either soil or rock crevices needed for nesting burrows.
Feeding
Sooty Shearwaters forage by plunging into the water from low flight, making shallow dives from the surface, or seizing prey at or just below the surface, to catch various small fish, shrimp and other crustaceans, squid, and jellyfish. These birds swim well underwater, propelled by their wings, and may feed in association with other seabirds and marine mammals, often following whales in particular to catch fish disturbed by them. They also follow fishing boats to take fish scraps thrown overboard.
Reproduction
The nesting season for Sooty Shearwaters in Australia and New Zealand runs from September to May. The birds nest on islands in nocturnally active colonies. Five- to nine-year-olds may begin breeding; they typically mate for life. The pair may perform dueting courtship calls. Both parents dig a burrow up to 10 feet long, or find a suitable rock crevice, and line the nest chamber at the end of the burrow with grass and leaves. Both parents incubate the single white egg for up to 56 days. Once hatched, parents spent their days feeding at sea. Returning to feed the chick at night, they typically crash land through the tree canopy and hit the ground with a resounding thump. These noisy nocturnal visitations occur with less and less frequency as the chick matures. The parents eventually cease to visit, and finally, after about 97 days in the nest, the chick departs from the nest by night, and heads off to sea.
Migration
Tracking tagged sooty shearwaters by satellite, researchers recently mapped the small bird's annual 74,000-kilometer search for food in a giant figure eight over the Pacific Ocean, traveling north from their southern Australia and New Zealand breeding colonies via Polynesia at the end of the nesting season in March to May, to their foraging grounds in Japan, Alaska and California by September, and then returning to their breeding colonies by November. Making this journey—the longest migration ever electronically recorded—in only 200 days, the birds averaged a surprising 350 kilometers daily. In some cases, a breeding pair made the entire journey together. Some non-breeders are present off the California coast during all seasons.
  • 20,000,000
  • 2,800,000
Population Status Trends
Although still one of the world's most abundant species, Sooty Shearwaters have been disappearing from former nesting islands. In recent years, their numbers have also declined significantly off the North American west coast. The Sooty Shearwater joined the 2006BirdLife/ IUCN Red List of Threatened Species as a "near threatened" species; it had never been previously listed. The bird is also listed on the 2005 New Zealand Threat Classification System as being in "gradual decline."
Conservation Issues
While the global population is still large, during the last two decades, the number of Sooty Shearwaters on the California coast has declined by 90 percent. Other research indicates that between 1969 and 2000 there was a 37 percent decline in the number of Sooty Shearwater burrows and reduced burrow occupancy on the largest breeding colony for the species, in the Snares Islands off New Zealand. Mainland colonies are also in decline.

In southern New Zealand, where they are known as titi or muttonbirds, young Sooty Shearwaters are hunted in their burrows by the native Maori for food and oil; they are also sold in stores throughout the country. This practice, called "muttonbirding" is considered a customary right for Maori groups and allowed by special legislation. A total of about 250,000 young birds are killed annually. While this represents a small part of the bird's declining numbers, it would be well advised to reconsider the size of such an activity while populations are plummeting. 

Recent evidence shows that declines both at New Zealand breeding colonies and at wintering grounds in the eastern North Pacific, may result from rising sea surface temperatures in the Pacific and from commercial fishing interaction. Sooty Shearwaters are particularly vulnerable as they dive for freshly baited longline fishing hooks and get caught in trawl nets. They are also vulnerable to changes in their food supply, which may result from both climate change and commercial fishing. Because Sooty Shearwaters have a global lifestyle, they may be important indicators of climate change and ocean health.
What You Can Do
Never let balloons drift off; shearwaters can become entangled in the strings, and marine mammals and turtles can mistake the balloons for food.

Join beach cleanups in your area. Properly discarding of debris, particularly plastic, will prevent shearwaters and other seabirds from eating it.

Make environmentally-friendly seafood choices, which helps protect the marine life that Sooty Shearwaters and other seabirds depend upon. Learn more at http://seafood.audubon.org/ or http://www.mbayaq.org/cr/seafoodwatch.asp.

Reduce your use of fossil fuels and don't discard used oil into city sewers or municipal water supplies. Transporting fuel inevitably results in oil spills, which can end up in the ocean where shearwaters rest and feed; if their feathers become oiled, the birds are no longer waterproof and cannot survive.

Cut up monofilament fishing line, which can entangle seabirds, prior to discarding it.

Use alternatives to pesticides, and dispose of old pesticides responsibly. Pesticides can wash into the sea where shearwaters live, potentially affecting reproduction. Learn about healthier pest control at Audubon at Home

Find out about actions you can take including Audubon programs and activities.
More Information
Learn more about international seabird conservation efforts at the BirdLife Global Seabird Program ; the North American Bird Conservation Initiative ; and the North American Waterbird Initiative.

Learn more about ocean conservation.

Learn more about this species and other birds through these resources.
Natural History References
Alsop, Fred J. Birds of the Mid-Atlantic. DK Publishing, Inc., New York, 2002

Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996

Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, Inc., New York, 2000

Scott Shaffer, et al. TerraNature report: 2007.
Conservation Status References
Alsop, Fred J. Birds of the Mid-Atlantic. DK Publishing, Inc., New York, 2002

Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996

Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, Inc., New York, 2000

Scott Shaffer, et al. TerraNature report. 2007