In August 2003, a team from the Wildfowl and Wetlands Trust and BBC Radio 4 travelled to Arctic Russia.
There they joined a team from the Nenetski State Nature Reserve in a project aimed to discover the as yet unknown migration routes of Bewick and Whooper swans.
Arctic Russian climate information
Latest weather update
Swan facts
- Although we are familiar with three species of swan, the Mute, Bewick and Whooper, the latter two only winter in Britain.
- Bewick swans fly 2200 miles from their breeding grounds in Arctic Russia to Britain, but biologists have no idea about the route that they take.
- Although the experts know Whooper swans that breed in Iceland migrate to Britain for the winter, absolutely nothing is known about the wintering areas of the Whooper swans of Arctic Russia.
- Whooper swans fly at varying heights, from 100m to 1,300m above the ground, and can reach speeds in excess of 50mph.
- Strong winds can blow swans off their migration course.
- Autumn migration normally begins in late September or October.
Arctic Russian climate
The northern coastline of the Russian Federation is within the Arctic Circle and is frozen for much of the year. The lack of sunlight during the winter contributes to the dominant feature of the Russian climate - the cold harsh winter.
The Kanin Peninsula, one area where the swans breed, sees temperatures drop to an average of -10°C in February after three months of little to no sunshine. The average temperature is below freezing for over half of the year, rising to an average maximum of 9°C in July.
Swans and the weather
Professor Colin Pennycuick, world authority on bird flight and migration, is consultant to the project. His study of the Whooper swans that breed in Iceland showed they have no weather forecasting ability.
We met up with Colin to find out more about how the swans will cope with the weather they might encounter during their migration.
"The swans should have moved by the 26 / 27 September." Colin told us "Although we are not sure what tells them it is time to go. If it is freezes then they can't feed, but while they have plenty of food why should they move?"
How important is the weather in their migration?
"Generally migrating birds depart when the wind direction is 'sensible' [blowing in the right direction] and conditions are clear. But they can't see what is happening further down the route. They take off when it is good and hope for the best."
"If there is bad visibility and low cloud - they don't like that. At 5km [visibility] they will start to think about landing and at 2km they will stop." (This is comparable to the conditions a pilot of a light aircraft will fly in while following visual flight rules.)
While a strong head wind will stop the swans from taking off on their migration, if they encounter one along the route they will keep going even in a head wind of up to 45mph!
The drop in temperature, resulting in the breeding area freezing over, is most likely to start the migration as the swans will no longer be able to feed.
Ideal migration weather?
"The best conditions will be reasonable visibility, a cloud base that is not too low and a north easterly to south easterly wind. The temperature is unimportant."
We asked Colin what would happen if the temperature drops below freezing and the wind is coming from the wrong direction for the swans' flight to their wintering ground.
"I don't know the answer. That's one of the questions we hope to answer in this project." While the swans are able to indulge in hyperphagia (overeating to build fat reserves for migration) they have no incentive to leave.
But once their feeding ground freezes over, they will start to use up the fat reserves that are essential to get them to their first stop in St Petersburg.
Latest weather update
BBC Broadcast Meteorologists Peter Gibbs and Penny Tranter are keeping a close eye on the weather along the migration route.
Peter Gibbs looks at how the weather has affected the migration so far and what conditions the swans are currently experiencing.
"We had to wait a long time for our swans to get the migratory urge, but the weather certainly didn't encourage an early departure. In fact, conditions in the Pechora delta region of Arctic Russia stayed exceptionally mild until well into mid-October due to persistent southerly winds."
"Winter finally arrived around the 20th, with several inches of snow on the ground and temperatures falling well below freezing. Interestingly, most of the Bewick swans headed off just before the coldest weather arrived, but the Whooper braved the ice and snow for several days before moving out."
Current conditions
"Weather conditions are still very mild across Southern Scandinavia and the Baltic states, with extensive low cloud, mist and drizzle. So not ideal flying weather, and nothing to hint to our birds that winter is on the way."
"Things are set to change by the weekend, however. Cold winds will sweep in from the northeast, dropping temperatures below freezing and also giving the birds a chance to pick up a tail wind which potentially could take them all the way to the UK."
Related links:
- BBCi Radio 4 - Migration
- BBCi Weather - Russian Federation Climate
- Wildfowl and Wetlands Trust
