Winter gales sweeping the island have not deterred breeding pairs of Bermuda’s national bird returning home.

During a lull in the weather this week, Jeremy Madeiros, the Department of Environment and Natural Resources’s principal scientist for terrestrial conservation, ventured out to Nonsuch Island and found 11 out of 38 nests in the “A” cahow colony occupied by freshly returned birds.

He found six nests with eggs, and five with males awaiting their respective females.

Jean Pierre Rouja, of Nonsuch Expeditions, said that during an extreme squall at 3am yesterday, an incoming male cahow was spotted on camera at the Nonsuch Island reserve.

The bird crash-landed into the bay grape thicket on the edge of the colony before going off camera.

A minute later, it appeared on CahowCam 1 in the shelter of its burrow, where it settled to await the arrival of its mate.

Viewers were invited to check the live camera online because the female is expected to return over the next few nights. Usually, she will lay her single egg within an hour of arrival.

Mr Rouja said the appearance by one of the rarest seabirds on the planet would be “a major event to witness”.

On December 31, Mr Madeiros confirmed the early arrival of the birds when he found a female cahow at Nonsuch Island.

“This female was at a healthy post-laying weight of 340 grams, while her egg weighed 56 grams,” Mr Madeiros wrote in a post online.

Last Friday, the scientist travelled out to Nonsuch — accompanied by a student — for further checks on the birds and discovered several cahows had returned to nest.

A male cahow, which was tagged and moved to Nonsuch Island as a chick back in 2008, was incubating an egg, while the female had left him to the task and returned to sea.

Mr Madeiros said the male weighed “an impressive” 446 grams.

Another male cahow was seen sitting in a nest waiting for the return of his female companion.

Three female birds were incubating eggs.

Mr Madeiros said a gale later that night was expected to bring a “surge of returning cahows” to lay their eggs, as the birds favour strong winds.

That expectation was met when the surface camera on the Nonsuch Expeditions website captured cahows zooming in over the colony, mainly between 8pm and 9pm.

He saw several birds swoop down and hurry inside their burrows.

Mr Madeiros said: “Strong winds are due to continue for at least a few days more.

“So I expect by the time I get back out to the islands, many more of this critically endangered seabird will be back and contentedly incubating their single eggs.”

After returning from the open ocean and carrying out courtship, mating and nest-building in late October and November, cahows typically return to sea for five weeks during November and December, when they feed intensively.

The female develops her single large egg while the male packs on fat reserves to start the first long incubation of the egg, which lasts up to 15 days.

The females then return to sea to recover from laying an egg equivalent to 20 per cent or more of their body weight.

Mr Rouja said cahows would only approach land under cover of darkness and fly in “ideally” on the front edge of a storm or squall, where they ride the wind to save energy.

• To view movements of the cahows over the next several nights, visitwww.nonsuchisland.com