The puffin population on one of the UK’s largest colonies has increased by a third since 2017, with more than 100,000 individuals now present according to a recent on the ground survey.
NatureScot and the UK Centre for Ecology & Hydrology (UKCEH) have completed a count of burrows on the Isle of May National Nature Reserve (NNR) in the Firth of Forth.
The count revealed there are around 52,000 occupied puffin burrows on the island, compared with 39,000 in the last survey seven years ago – a 33% increase.
Mark Newell, UKCEH’s field manager on the island warned the figure may mask a recent decline in the species, however, and that the number may have risen to a peak around 2021 before falling back in the last two years.
Scientists remain concerned about the ongoing impact of food supplies and climate change on populations.
Mr Newell said: “On the surface the latest estimate of a 33% increase is really positive, and it’s great that there are more than at the last count, but there is still cause for concern.
“This increase in numbers of puffins came as a bit of a surprise to us. Each year we follow a small colony of birds that are fitted with coloured identification rings, and the number we have seen has been below average in the last two years.
“There was a period of high breeding success and survival for more than ten years prior to this, and we believe that the population increased substantially after the 2017 count.”
The Isle of May is home to the third largest population of Atlantic puffins in the UK, after St Kilda and the Shiants. The island is also home to tens of thousands of other birds including shags, guillemots, razorbills and kittiwakes.
Field workers at UKCEH and NatureScot spent several days sweeping back and forth across the whole island counting each hole in the ground and assessing whether it was excavated by a puffin or rabbit.
A sample of plots was then checked carefully to determine whether they were occupied by puffins and this correction factor was applied to the whole island count.
David Steel, NatureScot’s Isle of May National Nature Reserve manager, said: “The count is a mammoth undertaking, involving 13 people crossing the island counting every puffin burrow.
“We didn’t know what to expect when we began. In the last seven years puffins have faced a lot of challenges so there was a fear that numbers were going to be down.
“As the count progressed I began to get a sense the result might be better than expected — in one area alone there were 11,000 puffins.”
He added: “People come from all over the world to see the iconic Isle of May puffins so it’s fantastic news that the population of these brilliant and hardy birds has increased.
“Seabirds across the UK are facing multiple challenges, including marine heatwaves, climate change and of course in recent years for some species, bird flu, so we’re delighted with this news.
“We will be monitoring these birds closely as the summer progresses and hope they continue to have a good year.”
Puffins are renowned for their colourful bills and comical behaviour. The UK holds around 10% of the world’s population, with around 5 million of the birds.
There have been serious concerns about the species’ fortunes, however, and in 2015 the International Union for Conservation of Nature (IUCN) upgraded its status from “least concern” to “vulnerable”.
UKCEH has been monitoring colonies on the Isle of May for 50 years, and its long-term research has shown that species have struggled with the impacts of climate change.
Rising ocean temperatures can reduce the availability of puffins’ food sources, particularly sandeels, which affects their survival rates and ability to produce offspring. In addition, periods of heavy storms in recent years have killed large numbers of birds.
While puffins have been exposed to bird flu, there is no evidence of large-scale mortality among puffins on the Isle of May.
