The great
snipe could well be the fastest bird on
Earth over long distances.
After
following the birds' migration south from Sweden to central Africa
using tiny tracking devices, Swedish scientists found that the birds fly
non-stop over a distance of around 4200 miles (6760km) at a phenomenal
60mph (97kmh).
A lot of birds can fly either very far or very
fast, but it's rare to find one that can do both. The peregrine falcon
is possibly the fastest bird on the planet: it reaches a startling
200mph (322kmh), but only while diving to catch its prey. And the Arctic
tern flies further than any other bird during its migration – around
50,000 miles (80,500km) from the Arctic to the Antarctic and back again.
Although this is an incredible feat for such a small bird, it doesn't
fly at great speed.
'We know of no other animal that travels this
rapidly over such a long distance,' write the authors in their report,
published in the Royal Society journal Biology Letters today.
What's also unusual is that its migration route takes it over land that is perfectly suitable for a stopover.
'We
never expected record-breaking flights for this ordinary bird. Along
its routes, the snipes have plenty of opportunity to stop over and feed
on earthworms, insects and other invertebrates and this is exactly what
land birds normally do,' says Dr Raymond Klaassen from Lund University
in Sweden, lead author of the study.
Migratory birds almost always choose to stop over during their
migrations if they can, at a place where they can rest and refuel before
continuing their epic journeys.
Even though Arctic terns fly
over the Atlantic, they still stop to re-fuel on surface fish on the
way. On the other hand, the bar-tailed godwit flies from Alaska to New
Zealand with no stopover, 'because it has no choice,' says Klaassen.
Flying
long distances has its costs. Migratory birds need to have the
necessary fuel onboard before they set off. This invariably means
they're not agile, because they have to be so fat, which could make them
vulnerable to predators. But that doesn't seem to put the great snipe
off.
Before this study, scientists had almost no idea where the endangered birds go once they leave Scandinavia.
'We
thought they might go to Africa, but we didn't know where. Also, nobody
sees the great snipe over the rest of Europe. We put this down to them
being so elusive and thought tracking them would reveal the other places
they hide,' says Klaassen.
The only real way to find out was to fit them with tiny tracking devices, called geolocators.
The actual size of the geolocator.
These
devices – developed at the British Antarctic Survey – weigh just 1.1
grams and, including attachments, make up a fraction of a per cent of an
adult bird's body weight. They record light intensity; when this data
is fed into a computer program, scientists can figure out when and where
the birds travelled.
After the breeding season, but before the
annual migration, the researchers fitted 10 male great snipes at
Jämtland in Sweden with a geolocator each. Exactly a year later, the
scientists managed to retrieve three geolocators from three birds when
they returned to Sweden after their northward migration.
Klaassen
and his colleagues found that one bird flew 4225 miles (6800km) from
Sweden to central Africa in just 3.5 days. The other two birds flew 3833
miles (6169km) in three days, and 2870 miles (4619km) in two days.
'We
think maybe the feeding conditions are so good in Scandinavia, the
birds take advantage of the opportunity to feed up,' Klaassen says.
Indeed one report says that come autumn, the birds are so fat, they're barely recognisable from how they looked in May.
The
great snipe is an endangered species. 'Its numbers have gone down a
lot, and it's almost disappeared from mainland Europe. It's now
restricted to the mountainous regions of Norway and Sweden,' adds
Klaassen.
The feeding grounds seem to be more important than
researchers realised. 'We need to find out exactly where they're feeding
and what they're feeding on. It would be good to see them before they
migrate, when they're really fat,' he says.
Scientists have long
known that snipes are incredibly fast birds. The word 'sniper'
originated in the 1770s among soldiers in British India: if a hunter was
skilled enough to kill an elusive snipe, he was called a sniper.
Great
snipes breed in Scandinavia from mid-May to early-July. The birds leave
their breeding ground from early-August onwards. The return northward
migration happens between March and April.