Manx Shearwater

Puffinus puffinus

(c) Glen Tepke
  • PROCELLARIIDAE
  • Shearwaters, Fulmars, Petrels
  • Procellariiformes
  • Pardel pichoneta
  • Puffin des anglais
Introduction

Once a rare visitor to North America, the Manx Shearwater has recently established small populations here. This nocturnal, burrow-nesting bird is an excellent flier—its stiff, rapid wing strokes are followed by the shearing glides low over the water that characterizes this species. The Manx Shearwater became known as the first bird to demonstrate long-range homing abilities, when adults taken from their burrows in Wales performed the 5,150-kilometer journey back home from Boston in only 12 days.

Appearance Description
Manx Shearwaters average 13.5 inches in length, with a wingspan of 33 inches, and a weight of one pound. This medium-sized shearwater is dark above and pale below, with white under-tail coverts extending almost to the tip of the short tail. It is distinguishable from other shearwaters by a pale crescent behind the ears. Black extends from the bill to cover the eye and auricular openings.
Range Map
Courtesy Kenn Kaufman
Range Distribution
Although this shearwater breeds locally in Newfoundland and rarely south to Massachusetts, most of the population breeds in the British Isles. The primary breeding range includes the Westmann Islands in Iceland, the Faeroe Islands, Great Britain, Ireland, France, the Azores, Madeira, and the Canary Islands. Middle Lawn Island in Newfoundland contains the largest North American breeding colony.
Habitat
Off North America, Manx Shearwaters generally occur over cooler water. They often feed close to shore, and nest mostly on small islands near the mainland. While the Manx prefers cold water, the very similar Audubon's Shearwater prefers warm water.
Feeding
The Manx Shearwater forages by diving into water from low flight, making shallow dives from the surface, or seizing prey at the surface, or just below, then utilizing its ability to swim underwater. It feeds on a variety of common small fish, including herrings, sardines, and sand lance. Squid and crustaceans are also consumed. Adults seem to be attracted to small fishing boats. They may forage as far as 600 miles from their nesting grounds, returning at night.
Reproduction
The birds nest in dense, nocturnally active island colonies. Five year old Manx Shearwaters may begin breeding, and typically mate for life. The pair digs a burrow up to six feet in length, which they may reuse the following year. The nest chamber at the end of the burrow is lined with plant material. The pair spends significant amounts of time in the nest for several weeks before the single white egg is laid. Both parents incubate the egg for up to two months, and feed the chick for another two months, before finally abandoning it. The chick leaves the nest a little over a week later, heading off to sea alone.
Migration
The breeding season off northeastern North America lasts from May to October. Many shearwaters begin to move north in early spring. European colonies tend to winter off the east coast of South America. Banding studies have shown that British breeders typically winter in the seas off Brazil, although some individuals may wander further afield. There is evidence of increasing numbers wintering in the Magellan Straits.
  • 550,000
  • 540
Population Status Trends
Manx Shearwaters—particularly the larger, protected European colonies—have recently experienced moderate increases. A surplus of potential breeders from Europe may have contributed to range expansion and the establishment of North American colonies. Manx Shearwaters were found nesting in Massachusetts in 1973 (but not since) and nesting attempts are made annually at Matinicus Rock, Maine and more are being reported off the North Carolina coast. However, during the last several centuries, declines have occurred at some North Atlantic colonies. CBC data also show declines.
Conservation Issues
During the 1600s, Manx Shearwaters were harvested extensively in Europe; fledglings were extracted from burrows with iron hooks, killed, salted, and barreled for later boiling. Historically, the birds were also used for lighting-oil in lamps, ploughed into soil as fertilizer, and caught for use as lobster bait. Passage of the Wild Birds Protection Act of 1880 in Great Britain eliminated these practices; to a lesser extent, chicks are still hunted for food in Iceland, the Faeroes, and the Balearics. 

Manx shearwaters in Scotland have been found to contain organochlorines from pesticides. Heavy metals recorded in shearwater tissue include zinc, cadmium, and mercury. Manx and related shearwaters are highly prone to crashing into structures after being blinded by bright lights. Some drown via entanglement in sardine fishery nets in the Bay of Biscay. On some larger offshore breeding islands in Europe, overgrazing and the resulting erosion has limited available habitat, restricting nesting to cliffs and other inaccessible sites. Introduced animals have been implicated in reducing or eliminating shearwater populations, including pigs in Bermuda, feral cats in Iceland, and rats on the Isle of Man. Burrows may collapse, and incubating shearwaters may desert, after nest inspections by researchers, particularly if frequent. 

Due to intense competition for suitable nest sites, the availability of dry, smooth burrow sites is an important factor in shearwater population expansion and breeding success. Population reduction may arise from burrow competition. Shearwaters take readily to artificial burrows; wooden burrows have been used in Newfoundland colonies where natural burrows are in short supply.
Transplanting shearwater chicks to unoccupied islands, with subsequent broadcasting of calling shearwater recordings to attract returnees, has been attempted in Great Britain, with still uncertain results. Abandoning grazing has aided shearwater recovery at several colonies in Great Britain. Gull control has also resulted in lowered shearwater mortality. The shielding of strong white lights, coupled with their replacement by subdued colored lights, and intense rescue efforts for disoriented shearwaters, are effective strategies for mitigating disorientation.
What You Can Do
Never let balloons drift off; shearwaters can become entangled in the strings, and marine mammals 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 Manx 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. 

Find out about actions you can take including Audubon programs and activities.
More Information

Learn more about international seabird conservation efforts at the North American Bird Conservation Initiative, and the North American Waterbird Initiative .  

Learn about ocean conservation at http://www.livingoceans.org/index.shtml 

Learn more about this species and other birds through these resources.

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

Lee, D. S., and J. C. Haney. 1996. Manx Shearwater (Puffinus puffinus). In The Birds of North America, No. 257 (A. Poole and F. Gill, Eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C. 

Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, Inc., New York, 2000
Conservation Status References
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996 

Lee, D. S., and J. C. Haney. 1996. Manx Shearwater (Puffinus puffinus). In The Birds of North America, No. 257 (A. Poole and F. Gill, Eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C. 

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