A Tern of Events

Renowned for being home to over 3000 pairs of Arctic terns every year during the breeding season, the Skerries provides an extremely important habitat for ground nesting sea birds, including terns, puffins and gulls. The group of small islets are located about 3 km off the north-west coast of Anglesey. Their rough, rocky terrain combined with sparse vegetation makes them inhospitable to humans. Yet for nesting sea birds, they provide the space and conditions to host thousands of broody pairs.

Taken from the shingle ridge at Cemlyn, looking towards the colony ‘dreading’


Over the past few years, the Skerries (managed by the RSPB) have been in the news due to the success of increasing pairs of roseate terns, which are the UK and Europe’s rarest seabird. Roseate terns like to nest in amongst other terns, and the Skerries allows them to do just this, nestling in amongst the Arctic terns, along with over 300 pairs of nesting common terns too. Sadly, this year the news is not that of success, but a failure of the entire tern colony.

Wardens, who spend the season observing the colony, stepping in if anything looks untoward or like it might be detrimental to the success of the colony, typically look after the reserve over the Spring and Summer months However, this year was different. With Covid-19 restrictions and furloughed staff, the RSPB were unable to position wardens on the islands, which seems to have been critical.

An Arctic tern. Photo credit: Gillian Day

A pair of peregrine falcons nested on the Skerries, which was most likely to have been the cause of the desertion, and could have been mitigated against had wardens been present. This unfortunate event highlights just how important it is to have people on the ground looking after these birds. It is crucial that tern colonies are wardened as loss of habitat and disturbance by people has made it much more challenging for terns to breed.

The colony island at Cemlyn on a calm day


Yet all is not lost for this year! Terns are adaptable birds, and have the ability to move and re-colonise swiftly. Luckily for Cemlyn, our reserve situated on the north-west coast of Anglesey, not so far from the Skerries, we have welcomed many more Arctic and common terns to the colony. Many of these have settled quickly, got down to business, and are already incubating eggs after being there just a week or two. We believe we’ve inherited at least another 1500 terns, making it the most successful year for common and Arctic terns recorded at Cemlyn. Where they’ve found space amongst the 2000 pairs of breeding Sandwich terns, 130 breeding pairs of common and Arctic terns that were already there, not to mention the nesting black headed gulls, we will never know! But Cemlyn is a noisier and more hectic than we’ve seen it in recent years, and it’s a marvel to watch! Then again, it’s been lucky enough to continue to be wardened throughout Covid-19.

What happened to the rest of the terns that deserted the Skerries? We’ve yet to find out. Some will have gone to other colonies, and in time we will know more. For now, we are keeping everything crossed for the success of the Cemlyn colony, and we hope to see more returning in years to come!

In these unprecedented times, our Cemlyn terns are in need of help. To find out more information about the Cemlyn appeal, please visit our Cemlyn Appeal.

For more information on the conservation of the roseate tern, check out the Roseate Tern Life Project.

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