Bermuda's Cahow population is growing steadily, with a record number of pairs last year and two new pairs already spotted this month.

But the long-term survival of the Island's famous but little-seen resident will only be ensured if a colony of the birds can be established on Nonsuch island, Government Conservation Officer Jeremy Madeiros said.

"We're running out of time with sea levels rising and changing weather patterns," he said. The current Cahow nests are far too vulnerable to severe storms, which seem to be increasing.

Mr. Madeiros hopes to establish a Cahow colony on Nonsuch island by 2004.

It will be a tricky manoeuvre, however, which will require planning as well as luck to complete.

Cahows first venture out of their nests, after their parents stop returning to feed them, for only a brief period of days to exercise and study the stars.

They memorise their position with this celestial guide and prepare for a journey that will take them from Bermuda for five to eight years.

They spend the time at sea - sleeping in thermal spirals and never touching land - and only return to Bermuda when mature and ready to start families of their own. The stars then guide them back to within one metre of the nest they left so long ago.

To convince Cahow chicks that Nonsuch is their true home, Mr. Madeiros will have to move them from their nests after the parents depart but before the chick begins to exercise.

He must monitor the nests carefully and continually to capitalise on this small window of time.

But the race against the uncertainty of weather makes the move a necessity.

The rocky, small islands which currently serve as Cahow nesting grounds are low-lying and too vulnerable to storms.

"If a fast-moving hurricane came through they would not have time to get out," Mr. Madeiros said. "They would drown in their nests."

The Cahow project would be set back at least 50 percent should a storm hit while the birds are nesting.

On Nonsuch, the Cahows will be better protected and Mr. Madeiros suggested and the number of pairs might rise into the hundreds.

Only at 1,000 pairs will this relative of the petrel - believed extinct for 300 years - be removed from the endangered list.

"Once their numbers reach a certain level, the population will increase at a much higher rate," Mr. Madeiros said. "You have to reach a certain plateau."

It took three decades for the bird's numbers to double after Dr. Davis Wingate began his dedicated project to bring the Cahow back from the brink.

But the second doubling took place in just 16 years, Mr. Madeiros said, and the third only five.

If they can be relocated before a major storm finds Bermuda, there is good reason to hope.