31 August 2004

Christchurch’s migrating godwits expected to arrive earlier

A poor breeding season in the Arctic Circle is likely to mean the bar-tailed godwits will return to the Avon-Heathcote Estuary earlier this year, says Christchurch City Council ranger Andrew Crossland.

He has been getting emails from ornithologists and other birdwatchers in Russia and Canada reporting that unusually frigid conditions across the Arctic this northern summer have resulted in a general breeding failure by migrating shorebirds, including the bar-tailed godwits which each year fly 14,000km to spend the southern summer in Christchurch.

This year, the City Council is organising a spring celebration to mark the arrival of the first godwit migrants. The Christchurch Cathedral bells will ring for 30 minutes when the first birds are seen on the estuary.

They would normally arrive around the third week of September, but in the last few weeks, northern birdwatchers have been reporting very early massings of birds along the coast in preparation for migration.

“The godwit breeding ground is tundra, moss and swampy tarn, where they feed on insects,” Mr Crossland says. ”After breeding, they move to the shorelines and estuaries along the Alaskan coast to build up for migration by feeding on shellfish and sea worms.

“It’s hard to know, but we have reports of failed breeding all over the Arctic. They only have a brief window of opportunity to successfully breed and raise their young. There are about two months of 20-plus hours of daylight when the permafrost melts and inspect life booms, providing food for the bids. If the godwits failed to breed successfully, they’ll give up and come back early,” he says.

After spending the southern summer resting and gaining weight, the bar-tailed godwits leave in March for the 14,000km flight back to their northern hemisphere breeding grounds.

ENDS

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