Balmier weather delays migration flights

GEESE, ducks and swans that spend winter in northern Europe are delaying their migrations by up to a month compared with 30 years ago, according to scientists.

Experts analysed three decades worth of data and six species out of the 15 they counted set off significantly later than in the past, with rising temperatures thought to be responsible.

The Wildfowl and Wetlands Trust (WWT) has warned that some species common to Scotland, such as the greylag goose and the tufted duck, are arriving in the UK in lower numbers as a result.

This was because many of the birds are not flying as far due to delaying their migrations.

Dr Geoff Hilton, head of species research for the Wildfowl and Wetlands Trust, said: “In this country, we’re at the end of the flyway for birds coming down from Scandinavia, Russia and Siberia. We’re almost the last stop, so some species aren’t coming at all. They’ll just stay further up the flyway.”

The shrinking flocks, Dr Hilton said, could have knock-on effects on the wetland habitat.

“These are quite big changes ecologically,” he said. “If you suddenly lose thousands of geese from a wetland, there are bound to be big effects on that wetland.”

Aleksi Lehikoinen from the University of Helsinki examined data from Hanko Bird Observatory in southern Finland, information built up over 30 years of observation.

The tufted duck showed the largest change in its migration, delaying by more than a month.

The study is published in the Journal of Ornithology.