Godwits cleared as bird-flu risks

Bar-tailed godwits fly about 11,000km over nine days from Alaska. Picture / Greg Bowker

Migratory birds now arriving in New Zealand pose virtually no risk of bird flu, says Tairua ornithologist and godwit expert Tony Wilson.

The 90,000 bar-tailed godwits that fly in between September and November are highly unlikely to be carrying any nasty hitchhiker on their 11,000km journey from Alaska, he says.

The bird-flu virus had been detected in waterfowl as well as poultry, but not coastal birds such as godwits, said Mr Wilson.

Waterfowl and coastal birds tended not to share habitats, and the risk of waterfowl such as ducks bringing bird flu to New Zealand was small because none migrated here.

"It won't be what we're catching from the birds that's going to be the worry," said Mr Wilson. "It's going to be from human beings."

His comments echo official warnings last week. The Ministry of Economic Development said human travellers were the most likely source of infection and Biosecurity New Zealand said it had not yet found any signs of the disease in migratory birds.

The migration of the lean, pink-beaked godwits is thought to be the longest non-stop flight of any bird.

"It's a miracle of nature that they can make it," Mr Wilson said as he watched a flock feeding in Tairua Harbour at the weekend.

The godwits begin arriving in about the second week of September.

Mr Wilson, who operates a bird-watching business called Manu Tours, said their journey took about nine days.

"They come in waves. The young birds can be several weeks later, up until November."

The godwits flock to harbours such as Tairua that are rich in pipi, cockles and the other food they need to replenish the 50 per cent of their body weight they lose during the flight. An adult godwit weighs 300g.

The greatest numbers of godwits are found at Miranda and Kaiaua on the Firth of Thames. They also migrate to eastern Australia.

The adult birds stay until March, before they fly back to Alaska, with a break in China or Korea on the way.

The chicks that are too young to breed stay in New Zealand for winter.

"They don't bother flying all that way back."

Bird-flu danger

* Migratory birds could in theory bring bird flu to New Zealand.

* But the main risk comes from waterfowl, which do not migrate here.

* Officials believe the biggest risk comes from human travellers.