success.

President of the Bermuda Audubon Society Mr. David Wingate said the fledgling crop increased to 23 pairs for the 1991-92 season from 18 pairs two years before.

"In the previous two years we've had very low success,'' he said. "The number of fledglings dropped to 19 last year and 18 the year before. It was the first time they were below 20 for almost a decade and marked a low point which began in 1987.'' Mr. Wingate said the cahow is only capable of laying one egg each year -- mating in November, laying in January and hatching in March. And he said the cause of the decline was three-fold: "There was a predation on the cahow by the snowy owl which got to Bermuda from the Arctic,'' he said. "They killed five birds that we know of, young cahows looking for mates. Those birds would've been forming pairs that season.'' Mr. Wingate said the birds may have also been affected by Hurricane Hugo, which didn't hit Bermuda but hit Charleston, South Carolina, and went through the cahow's feeding range in the Gulf Stream in the Bay of Georgia.

"In the autumn following the hurricane, a lot of birds failed to come back.'' Mr. Wingate said the cahow can normally cope with the average hurricane. "But Hurricane Hugo was obviously a very unusual event,'' he said. "It blew them onto the continent where they probably got lost in the forests. We don't expect an event like that to happen more than once every 10 or 20 years.'' But Mr. Wingate said the most important factor which led the cahow on the road to recovery was the turning off of a set of bright lights installed at the US Naval Air Station near Cooper's Island.

The president said the lights were installed in 1987 as part of security measures to guard aircraft and turned off last autumn.

"The cahow is a nocturnal bird,'' he said. "We believe they were just put off from their nesting. On full moon nights, the cahows don't come to breed.

It was not enough to discourage the established pairs but we hardly had any new pairs forming and the population started to go down.'' Mr. Wingate said the birds started forming pairs as soon as the lights were turned off.

"As a result no less than nine new pairs were prospecting last November and four of these produced chicks for the first time, raising the fledgling crop to 23 from 43 established pairs.

"I hope there will be a steady increase as these new pairs mate,'' he said.

"We should have five additional pairs next winter and if we're lucky, 28 the next year. That's the highest we've ever had, back in 1987.''