Wellington  - Forty godwits arrived in New Zealand Tuesday after a non-stop, 11,000-kilometre flight from Alaska, formally marking the start of spring, according to the Christchurch City Council.

Thousands of bar-tailed godwits spend the Southern Hemisphere summer on New Zealand estuaries and mudflats before flying back to Alaska in March to breed.

Traditionally, the South Island city of Christchurch rings its cathedral bells to mark the arrival of the first birds at the estuary of the Avon and Heathcote rivers and announce the start of spring to its citizens.

Scientists proved that the birds make their migratory flights without stopping by implanting satellite transmitters in an experiment two years ago.

They said no other creature had demonstrated such a feat of endurance. (dpa)