One of only three breeding pairs of common tern in Bermuda has welcomed offspring.

Former conservation officer David Wingate has renewed his appeal to the public to stay away from the buoy nesting site in St George’s Harbour.

“It will now be approximately another month before the chicks fledge and up to the point when they can fly on their own they remain extremely vulnerable to disturbance,” Dr Wingate said.

“The problem with buoy nesting is that if the chicks fall overboard they cannot get back up onto the buoy and soon drown, so I appeal to all boaters not to approach closer than 100’ and to back off if the adults begin dive bombing.”

It was the pair’s second nesting attempt, after their first one failed when a boat tied up to the buoy — despite a warning sign installed by Conservation Services identifying it as a nesting site — during the dinghy racing event on May 24.

Returning to dry land after seeing the eggs hatched, Mr Wingate added: “I have just returned from banding (ringing) the three chicks (all three eggs hatched) and taking the blood samples which enable us to examine the genetics and family relationships of the various pairs. My helper was Miguel Mejias who is also working with Jeremy Madeiros towards his Masters thesis studying the at-sea behaviour of longtails using data loggers.”

He said Lynn Thorne went along as photographer and took some pictures.

“If chicks fall off a buoy nest they can’t get back on, so boaters should stay well clear so as not to scare them into running overboard. Of course if they do and a boater sees this they can be grabbed from the water and replaced on the bout.”

Mr Wingate has been tracking common terns in Bermuda since the 1960s and recorded between 18 and 35 pairs annually.

Although never abundant, the population was decimated by Hurricane Fabian in 2003, which wiped out all the males and chicks, but spared the females, who migrate to their South American winter quarters much earlier.

The following year resulted in “total breeding failure” because none of the eggs were fertile, according to Dr Wingate. Although the population began to recover a couple of years later, it was decimated by another hurricane in 2008.

Only three viable pairs now remain, two of which have already successfully reared four fledglings this year.