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
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