Seal pups thrive on the Farne Islands

A grey seal pup
Published : 19 Dec 2018 Last update : 21 Jan 2019

The number of Atlantic grey seals born on the Farne Islands off the coast of Northumberland has increased by 50 per cent in five years. 

This year National Trust rangers counted 2,602 seal pups, compared to 1,740 in 2014.  

A large amount of sand eels (the seals' favourite food) and few predators are thought to be behind the increase in numbers.

A flourishing population of seal pups is also a sign that the sea surrounding the Farne Islands is in good health. Several areas of the sea are protected and fishing has been limited.  


Counting seal pups

National Trust rangers, who live on the islands for nine months of the year, count the seals every four days in the autumn once the pupping season begins. Watch how our rangers keep track of the pups by marking them with vegetable dye and find out why counting them is so important.

Thomas Hendry says: “A lack of predators and a plentiful supply of sand eels – which makes up about 70 per cent of the seals’ diet – has helped bolster our seal pup numbers.  

“This new record for the grey seal colony is certainly a milestone and could be good news for the health of our seas around the islands, indicating a good food supply due to fishing being limited partly due to several protected areas of sea around the islands.   

“Over the next few years we will monitor the effect of a growing seal population and to manage the island habitats accordingly.”

The rangers have also noticed that the seals have changed the place of their rookeries (breeding sites).  Previously most of the pups were born on the islands of North and South Wamses, but now many seals try to breed on Brownsman and Staple islands, which offer better protection from storms and high seas.

Record-breaking year for seals further afield

Seal pup numbers have also hit record highs at Blakeney Point in Norfolk, where rangers counted more than 3,000 pups in December, compared to 2,000 in 2014 and 1,000 in 2012. A peaceful and quiet environment is thought to be behind their success. 

Leighton Newman, a ranger at Blakeney Point, says: 'We are also fortunate to have a really supportive local community and visitors to the reserve.

'They have helped keep disturbance of the seals to a minimum, sticking to waymarked routes, staying clear of fenced off areas and ensuring that the seals have the space they need.'

National Trust volunteers helped the rangers count the pups between October and December. 

Seal pup and mother

Did you know?

Seal pups are born with bright white fluffy coats. Although they can swim at an an early age they don't normally leave the colony until they are two or three weeks old. This is when the seals shed their white coat and their dense waterproof fur has grown through. 

There are around 300,000 grey seals in the world and half of them live in British and Irish waters. The grey seal is a protected sea mammal, so the increase in numbers at the Farne Islands, which is home to the UK's largest seal colony, is good news for the global population.