A mighty bird story by Donie

A 25g Tiny songbird

'The northern wheatear'

 travels the world to migrate

 

Miniature tracking devices have revealed the epic 30,000km (18,640 miles) migration of the diminutive northern wheatear.

The birds, which weigh just 25g (0.8oz), travel from sub-Saharan Africa to their Arctic breeding grounds.

"Scaled for body size," the scientists report, "this is the one of the longest round-trip migratory journeys of any bird in the world.

The team reports its findings in the Royal Society journal Biology Letters.

The species is of particular interest to scientists, because it has one of the largest ranges of any songbird in the world; with breeding grounds in the eastern Canadian Arctic, across Greenland, Eurasia and into Alaska.

"Think of something smaller than an [American] robin, but a little larger than a finch raising young in the Arctic tundra and then a few months later foraging for food in Africa for the winter," said one of the lead researchers, Prof Ryan Norris from the University of Guelph in Ontario, Canada.

Prior to this work though, it was not clear where the birds spent the winter.

Heiko Schmaljohann, from the Institute of Avian Research in Wilhelmshaven, Germany, was a member of the team that carried out this study.

He and his colleagues visited the wheatears' breeding grounds in Alaska and Canada and fitted 46 birds with the satellite tracking devices.

"The [trackers] weigh 1.4g, including a harness that loops around the birds' legs," he told BBC Nature.

Continue reading the main story"When we see them, they're in the middle of a journey they do twice every year. When you think of the challenges they must face, you wonder how on earth they do it."

Dr Schmaljohann added: "[In the past] we totally underestimated the flight capability of birds in terms of migration.

"It seems that bird migration is limited by the size of the Earth. If the planet was larger, they would probably migrate even further."