North American population down by 64 per cent, Audubon Society says

Along with longer days and melting snow, spring in the Eastern Arctic brings back a familiar sight: plump little black-and-white snow bunt­ings.

But worldwide, snow bunting numbers are in a nosedive.

Today, there are 19 million snow buntings, down from 40 million birds 40 years ago, says the Audubon Society, which warns the disappearance of birds are sending the world an "environmental wake-up call" to curb global warming.

About 14 million snow buntings remain in North America. The steep drop in the snow bunting population represents a loss of 64 per cent, says the Audubon Society.

For more than 100 years, this U.S.-based group, named for the early American naturalist John James Audubon, has been working to protect birds, other wildlife and their habitats.

Snow buntings are 11th on an Audubon list of 20 common birds whose numbers are in decline.

The list, Common Birds in Decline, released July 14, says the snow buntings are not in immediate danger of extinction.

"We know 14 million snow buntings is an awful lot of snow buntings," Greg Butcher, the list's author and Audubon bird conservation director, told Nunatsiaq News. "But when there's that dramatic a population decline, we don't think that's right. We want to keep snow buntings common. We don't want them to become rare."

Butcher believes global warming is responsible for the "dramatic" drop in snow bunting numbers.

"We don't know anything else that is occurring on their range which would cause the declines we're seeing," he said.

Warmer temperatures in snow bunting breeding areas is probably causing earlier thawing of the tundra and allowing more woody plants to grow.

"These birds like very open tundra habitat, and so anything that is going to increase the vegetation on the tundra is not going to be good for snow buntings," Butcher said.

Unlike other Arctic songbirds, snow buntings build their nests between rocks, which offer protection from predators, but also leave them more vulnerable to cold. Increased vegetation between the rocks may put snow buntings at more risk of predation and exposed to temperature swings.

The list of common birds in decline came from a combination of sighting data from Audubon's yearly Christmas bird count program and results of the U.S. Geological Survey's annual breeding bird survey.

The snow bunting decline suggests other less numerous tundra-loving birds, such as snowy owls and shore birds, which appear to be even more susceptible than snow buntings to any habitat change, are also facing "severe threats."

As well, tundra birds may be losing ground as southern birds expand their range northwards. That's an option tundra birds don't have, Butcher said: "if they move north, they'll hit the Arctic Ocean, and they can't breed in the Arctic Ocean."

A study by Denmark's national environment research centre from the June 19 issue of Current Biology, which looks at plants, insects and birds northern Greenland, says noticeable changes are already underway in the High Arctic.

The scientists found some shore birds had moved their breeding time forward by an average of two weeks by 2005, compared to 1996, a change which may affect the birds' long-term survival in unpredictable ways.