Unique Bird the World
10 Jan 2014
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A tracking device which weighs less than a paperclip has helped
scientists uncover what they say is one of the world’s great bird
migrations. It was attached to a red-necked phalarope from Scotland that migrated
thousands of miles west across the Atlantic to the Pacific Ocean. The journey has never before been recorded for a European breeding bird. The red-necked phalarope is one of the UK’s rarest birds, and is only found in Shetland and the Western Isles.
The RSPB, working alongside the Swiss Ornithological Institute and
Dave Okill of the Shetland Ringing Group, fitted individual geolocators
to 10 red-necked phalaropes nesting on the island of Fetlar in Shetland
in 2012. Each geolocator weighed 0.6g and was fitted to the bird with harnesses made from tubing.
It was hoped the trackers would shed light on where the birds, which are smaller than starlings, spend the winter.
After successfully recapturing one of the tagged birds when it
returned to Fetlar last spring, experts discovered it had made an epic
16,000-mile round trip during its annual migration.
It had flown from Shetland across the Atlantic via Iceland and
Greenland, south down the eastern seaboard of the US, across the
Caribbean and Mexico, ending up off the coast of Ecuador and Peru.
After wintering in the Pacific, it returned to Fetlar, following a similar route.
Gender roles
Prior to this, many experts had assumed that Scottish breeding
phalaropes joined the Scandinavian population at their wintering
grounds, thought to be in the Arabian Sea.
Although long, the phalarope migration is beaten by some distance by
Arctic terns, which make a return trip of about 44,000 miles between the
North and South poles each year.
However, the phalarope is the only known westward migration into the
Pacific. This westward movement in late summer and autumn is into the
prevailing weather and in virtually the opposite direction to all other
migrants leaving the UK.
Numbers of red-necked phalarope in Scotland fluctuate between just 15 and 50 nesting males.
Malcie Smith of the RSPB told BBC Scotland he had almost fallen out
of his chair when the tracking results showed where the birds had gone. He added: “We are freezing up here in Shetland and it’s quite nice to
think of our red necked phalaropes bobbing about in the warm tropical
waters of the Pacific.
“What it tells us is that this bird isn’t part of an offshoot
population from Scandinavia. Our Shetland population is actually an
offshoot of a North American population.
“It means that what we thought was a kind of medium-distance migrant
is actually a long-distance migrant. It is one of the world’s great
migrations. “We’ve known for some time that birds undergo big migrations. We all
know about Arctic terns and swallows and this is pretty much in the same
ballpark.”
Scotland marks the southern limit of the breeding range of the small,
colourful waders, with the species far more abundant further north.
The birds are perhaps best known for turning the tables on
traditional gender roles, with male phalaropes incubating eggs and
raising young in the summer, while the female uses her brightly coloured
plumage to attract new partners. In winter, phalaropes congregate in large flocks at sea in regions
where currents create cold, nutrient-rich water and support blooms of
plankton on which the birds feed.
By continuing the project and retrieving more tags from phalaropes
after their winter migration next year, experts hope to learn the extent
to which the Scottish population may be impacted by future changes at
sea.
They also hope to learn how the species might respond to any change,
and whether any negative impacts in these wintering areas can be
mitigated by conservation management in Scotland.
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