Cahows thriving after record number of chicks born
Bermuda’s cahow population is thriving after a record number of chicks were born in the past two months.
And longtails have also started to make an appearance on the island - much earlier than normal.
Jeremy Madeiros, the principal scientist at the Department of Environment and Natural Resources, said that at least 15 chicks had hatched at the Castle Harbour nesting sites by the end of last month.
There are normally only three to five chicks hatched at the location this early in the breeding season.
Mr Madeiros added that a count of all locations revealed that so far almost 30 chicks had hatched – with more on the way.
He said: “In the next two weeks, as hatching continues, we should know the total number of cahow chicks produced this year by the breeding population.
“At the moment, it looks like there is still a good chance of beating the record of 73 successfully fledged chicks produced in 2019.”
Mr Madeiros, writing on the Nonsuch Expeditions website, said that an egg in a nest being filmed on a webcam would not hatch.
He added: “Although this may be upsetting for some people, most pairs of cahows only successfully produce chicks every other year, so as this pair did successfully produce a chick, named Nemo, in 2020.
“They are about average in their breeding success rate.”
Mr Madeiros said: “At present, the egg being incubated in the CahowCam 2 nest is fertile and developing well, and should hopefully be hatching in the next seven to ten days.”
Mr Madeiros said that longtails also made an early appearance this year, with hundreds flocking to the island in the last week of February.
He added: “On Thursday, February 25, when I visited Nonsuch Island, five of the six artificial tropicbird nests along the stairway leading up from the dock had adult tropicbirds peering warily at me from the nest entrances.
“In a normal year, tropicbirds are not normally visiting nests until mid to late March, so things are definitely running early with both species.”
Mr Madeiros said that teams were now rushing to install entrance baffles on all cahow nests to protect them from the longtail population.
He added: “In the earliest years of the cahow recovery programme, almost 75 per cent of cahow chicks were being killed by tropicbirds during nest invasions.
“Since the baffles were developed, with specially sized entrances that allow the slightly smaller cahows to enter but keep the larger tropicbirds out, there have been almost no chick deaths due to this cause.
“These baffles are taken out during the first stage of the breeding season, when the tropicbirds are still out at sea, to make it easier for returning young cahows to prospect for and find nests, and also to allow the female birds carrying large eggs on the verge of laying to enter the nests without restriction.”