Nearly all Bermuda’s cahows have returned to the islands around Castle Harbour to lay eggs and roost.

Jeremy Madeiros, a senior terrestrial conservation officer with the Nonsuch Preservation Project, wrote in the project’s blog that the 24-hour “cahow cams” had captured mixed news of the nests.

CahowCam 1 showed that its common pair arrived on the night of January 6, with the female, band number E0212, laying an egg an hour later.

The egg’s fertility was confirmed on January 15 and eight days later the embryo was found to be developing normally.

The pair, with the male’s band number E0197, started nesting together in 2010 and have had seven fledgeling chicks since.

CahowCam 2 showed that its typical male, band number E0174, had lost its long-term partner, band number E0172.

The pair, which had also started nesting together in 2010, had 12 fledgeling chicks, several of which have already returned to establish new nests around Nonsuch and Long Rock.

Mr Madeiros said that the female had suffered a “severe foot injury” in 2019 but still managed to raise three chicks before disappearing between June and October last year.

He added: “It is always sad to lose a member of a successful pair.

“I had translocated all four of the birds that ended up settling in the two CahowCam nests in 2005 and 2006, from the four tiny original nesting islets as near-fledged chicks to artificial nests on Nonsuch, included in the 100-plus chicks from the first Translocation Programme that I initiated after taking over as warden.

“As part of the programme, I then hand-fed them for two to three weeks and allowed them to imprint on and fledge from their new ‘adopted’ home on Nonsuch, to which 51 eventually returned and paired up four to five years later, including these four, in artificial nests usually right next to the ones they originally fledged from.”

Luckily, another young female cahow, with the band number E0643, which had fledged in a nest near Horn Rock and was looking for a mate, paired with number E0174 last November, despite his initial deflection.

The pair soon left, with the male returning January 15 and the female still in flight.

Cahows have returned to all 39 active nests since the first pair returned in 2009.

It was the first time that cahows had nested on Nonsuch since they were wiped out there in the 1620s by colonial hunting and predation.