26/12/2017
Greenland
White-fronted Geese make a 600-mile round trip each year to
overwinter in Scotland but not every bird finds it easy, according to new
research from Wildfowl and Wetlands Trust (WWT).
Specially designed bird ‘fitness
trackers’ have revealed what happens to the birds as they struggle over the sea
for long distances, trying to navigate the angry North Atlantic and getting
blown off course by unpredictable storms.
Migration is a particularly
vulnerable time for Greenland White-fronts. One goose took just 14 and a half
hours to fly from Iceland to Greenland, but two others took days to complete
the same journey, being forced to spend a lot of the time bobbing on the sea.
WWT researcher Ed Burrell has
just returned from the tiny island of Islay, Argyll, where he’s been
downloading data from the bird fitness trackers. He said: “We’ve just
downloaded all this amazing data from these individual birds to see what
they’ve been up to. From studying the leg from Iceland to Greenland in May this
year, we see what a difference a day makes.
“We can tell that the weather
turned on two birds who left the same evening, as they landed on the sea – so
they wouldn’t be blown further, of course. By using an extra gadget called an
accelerometer – a bird 'fitness tracker' so to speak – which measures the
movement of the tag, we can tell that they bobbed about for a bit. To avoid the
terrible conditions, the birds went for a swim.”
The blue-tagged goose left
Iceland at 3.30 am on 6 May in calm conditions, arriving in Greenland
14-and-a-half hours later at a speed of 33.5 mph. The green-tagged goose left
at 4 pm on 3 May accompanied by a good tailwind that later turned on the bird,
blowing it towards the Arctic Ocean and forcing it to hunker down in the sea.
It later landed in Greenland 53 hours after its journey began.
The red-tagged goose had it even
worse, leaving the same evening as Green, but taking a traumatic 63 hours to
complete the trip.
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