Transatlantic travels take Lowestoft's kittiwakes to Labrador and beyond
PUBLISHED: 09:00 16 September 2017
It's well established that bird migration is one of the great marvels of the natural world - but studies in a Suffolk seaside town are showing that it's even more miraculous than might be thought.
It’s a long, long way from Lowestoft to the Labrador Sea off icy Greenland’s coast. It’s even further to the chilly waters off New York’s Long Island. And both far-flung locations can be brutally inhospitable in winter.
They wouldn’t be most people’s best guesses as to where delicate gulls that spend the summer rearing young on the Suffolk coast ride out the winter’s depths.
But new research using hi-tech tracking devices has shown that some of the more adventurous kittiwakes that nest in the town wander widely and reach such far-off areas of the Atlantic Ocean during the northern hemisphere’s most inclement season. Meticulous scientific studies by the Kessingland Ringing Group have revealed the wildest of wintering areas of some of the birds that breed on Lowestoft structures that include Claremont Pier, Our Lady Star of the Sea Catholic Church and a concrete “cliff” at the town’s harbour that has been specially provided for them.
Results so far gathered in the ongoing research contradict the conventional concept that all migratory birds fly south from Britain for the winter. Some of Lowestoft’s kittiwakes do indeed head south, to waters off Spain and Portugal. But others head north and east, some to reach the mid-Atlantic area, gale-lashed Greenland’s offshore zone and even the eastern seaboard of the United States before making their oceanic migration back to Suffolk for the spring and summer.
Details of such epic journeys have emerged thanks to the painstaking efforts of the ringing group, whose members spend much of the time studying birds at Kessingland Sewage Works but who sometimes transfer their attentions to Lowestoft’s kittiwakes when the globetrotting gulls are “at home”.
The group’s work is carried out strictly in accordance with the stringent requirements of members’ bird-ringing licences which are issued and overseen by the Thetford-based British Trust for Ornithology (BTO). The work is supported by the BTO and is part of its national ornithological research. It is also supported by the conservation and study charity Seabird Group.
Some of the findings were presented by ringing group member Mike Swindells at a Suffolk Wildlife Trust Alde and Blyth Group meeting at Leiston United Church.
Early in the group’s kittiwake research, three in the Lowestoft colony had been fitted with tiny, lightweight GPS tags in addition to their coloured and uniquely coded leg rings. The harmless tags, fitted to the birds’ backs and designed to fall off when the individual moulted its feathers, showed that the birds had foraged at sea to a range of about 60 miles from the coast before returning to their nests, said Mr Swindells.
Further information was then gained by the use of tiny geolocators, of negligible weight, fitted to other birds’ colour rings. Such devices produced data on date and time and, crucially, light levels. Calculations made after the geolocators were recovered when the birds were re-caught at Lowestoft enabled the ringing group to establish where the birds had spent the winter months.
One bird, named Sophie, had wandered in the North Sea, the English Channel and the Irish Sea before spending part of January off Spain and Portugal, returning to the North Sea in February and Claremont Pier at the end of March, he said.
Another kittiwake, named Derek, was more adventurous. After wandering in the North Sea and the Irish Sea, by August 22 it was off the southern tip of Greenland. It ventured into the Labrador Sea before re-crossing the Atlantic to the Outer Hebrides and then Iceland and was back in the North Sea at the end of March.
Alan had spent nearly all his winter off Newfoundland before returning to Lowestoft while Carol ventured out to the mid-Atlantic. Scott had reached Long Island while George had stayed much closer to Suffolk, deciding not to leave the North Sea, said Mr Swindells.
Such travels broadly matched those of kittiwakes in other research projects, but there was one element of the ringing group’s research that may break new ground. It was that each bird effectively repeats its journey - whether Transatlantic or less wide-ranging - each winter.
It was assumed that such arduous journeys were made by some kittiwakes because they were exploiting rich food sources, the benefits of which outweighed the demands of such long-distance migrations, said Mr Swindells. The group’s studies were continuing, he added.
More information about bird migration and tracking projects can be found at www.bto.org/