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New England Seabirds
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The British Shearwater The Manx Shearwater got its common name because at one time it bred on the Calf of Mann, a small island just south of the Isle of Man between Ireland and Great Britain. It is the common shearwater around the British Isles and the most northern breeding shearwater. It winters in the waters off Brazil.
Taxonomy of Manx Shearwater is currently undergoing revision leading many to refer to it as the Manx Shearwater complex. There is disagreement about the apparent Manx Shearwaters seen in the Pacific. Harrison 1983 (2) identifies 3 subspecies of Manx Shearwater. Newer studies split the Atlantic birds into 3 species as shown in the table.
For purposes of the rest of this discussion I will be referring to the split Puffinus puffinus which is most likely to appear on our coast. Breeding Nests in burrows on high cliffs, grassy slopes, and rocky islands. Burrows up to 4 feet deep. Comes and goes from the nest only at night. Heavily preyed upon by Great Black-backed Gulls.
Shearwaters and other seabirds tend to gather in rafts on the water offshore of breeding colonies in the evening waiting for the cover of darkness to approach their burrows. In the picture above Manx Shearwaters are flocking on the water just off Skommer Island in Wales waiting for darkness. This is a good time to estimate the number of birds in the colony. For more about the author's trip to Skommer Island follow this link. Skommer Island Photograph taken by Emmalee Tarry with a Cannon Powershot camera from a rocking boat.
Video of Web Cam of Manx Shearwater Burrow on
Skommer Island
¹ From the CNN web page LONDON, England -- One of the world's oldest living wild birds is marking its golden jubilee by preparing to breed again. The Manx shearwater -- a far-flying gull-like seabird -- was probably born in 1952 and is thought to have clocked up about five million miles in the air. First ringed by ornithologists in 1957, the bird's journeys were made while migrating between Britain and South America. It was re-discovered on April 4 this year in a colony of several thousand others on Bardsey, an island off the Lleyn peninsula in north Wales. The shearwater had just returned from its South American wintering grounds and was preparing to breed when it was netted, as part of the British Trust for Ornithology (BTO) national bird-ringing scheme. Graham Appleton, the BTO's fund-raising manager, told CNN it was the fourth time the bird had been netted and released -- the other occasions being May 22, 1957, July 8, 1961 and April 16, 1977. Appleton told CNN: "Not only is this bird considerably older than you would expect, it is still breeding. "As long as they are still going, they produce young. Birds don't really have old age!" He said the estimated huge mileage it has covered is down to it living much of its life on the wing -- shearwaters are extremely economical fliers, gliding on wind currents rather than flapping continuously. "It comes to land only during the breeding season, when it seeks out an island where it can dig a burrow," he said. "It will stay at the colony until the end of the summer and will then head out back to sea where it travels around southern Atlantic, until next spring." He said that given its known age and its winter migration cycle which takes in Brazil, Argentina and Uruguay, it is estimated that the bird has travelled 500,000 miles, or the equivalent of a return trip to the Moon. Taking feeding flights into account, it has probably covered a total of five million miles. British bird expert Chris Mead told Reuters: "The only way you can tell a bird's age is by ringing it, and we know about all the other birds, so we can say it is the oldest. "It would not be uncommon to find birds aged between 15 or 20 years in a colony of shearwaters, but 50 years is absolutely remarkable," he said. Manx shearwaters, whose scientific name is Puffinus puffinus, are shy of the mainland where danger lurks in the form of predators like stoats, rats and birds of prey, the RSPB said. The Manx shearwater has a black back and wings with a white belly and at about 14 inches long it is slightly larger than a pigeon. The oldest wild bird ever found was a royal albatross that nested in New Zealand and was named Grandma, the Times said. The bird was at least 53 years old when it went missing. The previous oldest known wild bird in Britain was also a Manx shearwater, recorded in 1996 in Northern Ireland aged 41. According to the Guinness Book of Animal Records, the highest ever reported age of a bird is an unconfirmed 82 years for a male Siberian white crane called Wolf which died at the International Crane Centre in Wisconsin, U.S., in 1988. Experts are convinced that there are more venerable individuals still to be identified. Some, particularly in the parrot family, are thought to have hatched at the end of the 19th century. |