PUFFIN numbers in one of the UK’s largest colonies have fallen amid a tightening food supply and extreme weather conditions.
The number of burrows occupied by puffins on the Isle of May, in the Firth of Forth, has fallen by around 30% in two years.
NatureScot – who manage the island – say they found around 36,500 puffin burrows on the island in the latest survey, compared with 52,000 in 2024.
The Scottish Government’s nature agency blamed the drop in numbers on violent storms and rising ocean temperatures, which have restricted the supply of food.
Researchers described the decline as “disappointing and concerning” and warned that an increase in extreme weather events, predicted by climate scientists, could make the future even bleaker for the puffins.
NatureScot Isle of May Reserve Manager David Steel said: “This decline is disappointing and concerning.
“Puffin numbers on the island fell sharply in the 2000s and recovered in the 2010s but have now dropped again.
“The decrease appears to be linked to a combination of ongoing pressures on seabird food supplies, poor winter survival and increasingly extreme weather conditions.
“Unfortunately, this mirrors similar challenges that are affecting seabirds more widely.
“All of this underlines the importance of continued monitoring and conservation work at sites like the Isle of May National Nature Reserve, where data and research are playing a vital role in helping us to understand these trends and respond.”
Puffins can spend up to eight months of the year out at sea, only returning to land to breed in early spring.
They generally mate for life, and pairs often return to the same nesting spot each year where the female lays a single egg.
The UK Centre for Ecology & Hydrology (UKCEH) has been monitoring seabird colonies on the Isle of May for 50 years, and have long warned about species’ struggles with the impacts of climate change.
They worked on the island survey with NatureScot Rising and found that rising ocean temperatures has impacted the availability sandeels – one of the puffin’s principle food sources.
This has heavily impacted their survival rates and ability to produce offspring, while periods of heavy storms in recent years have killed large numbers of birds.
Mark Newell, UKCEH’s field manager on the Isle of May, said: “We believe that the puffin population has recently suffered from a series of extreme climate events, including marine heat waves and intense storms affecting survival in three of the last five winters.
“The concern for puffins and other seabirds is that climate scientists are predicting an increase in the frequency and severity of extreme events in future.”
Field workers at UKCEH and NatureScot carried out the count by sweeping back and forth across the whole island for six days, counting each hole in the ground and assessing whether it is excavated by a puffin or rabbit.
A sample of plots were then checked carefully to determine whether they are currently occupied by puffins, and this correction factor is applied to the whole island count.
Although the number of burrows was similar in 2026 and 2024, the occupancy rate was significantly lower this year.
Posting on social media a spokesperson for the Scottish Seabird Centre said: “Bad news from our friends at the IsleofMay National Nature Reserve today.
“Puffin numbers on the island have dropped by around 30% since the last burrow count in 2024.”
They added: “Tackling climate change must be central to protecting these iconic species for the future.
“In addition, better management of our seas is urgently needed to reduce other pressures and give seabirds the best chance of recovery.”
This year the Isle of May celebrated 70 years as a National Nature Reserve (NNR).
The Isle of May is located in the north of the outer Firth of Forth, approximately eight kilometres off the coast of Fife.
There are no permanent (human) residents, but the island was the site of St Adrian’s Priory during the High Middle Ages, and attracts approximately 11,000 visitors per year.
