I ddarllen y blog yma yng Nghymraeg cliciwch yma os gwelwch yn dda
For many people, autumn’s arrival mean leaves turning and falling off trees or creating new highways and byways for wildlife to forge their way through. Others might associate autumn with jays burying acorns or hedgehogs gorging on food in preparation for the harsh winter ahead. For RSPB Ramsey Island staff however, autumn’s arrival is heralded by grey seals coming onto the island’s shores for pupping season.
Image by Lisa Morgan: Grey seal on RSPB Ramsey Island.
The Pembrokeshire coast has the largest population of breeding Atlantic grey seals in the Irish Sea and Southwest Britain, whilst RSPB Ramsey Island supports the largest proportion within this region. Main pupping season takes place on RSPB Ramsey Island between late August and the end of October, meaning that autumn presents the perfect opportunity to witness this wonderful natural spectacle first hand.
Grey seals give birth on RSPB Ramsey’s open beaches and in numerous sea-caves around the island which can make it very difficult to see exactly how many pups are born each year. What we can do, however, is count the number of pups born on the big beach sites to give us an idea of how the population is doing as a whole. Using this counting method, an average of 320 pups can be seen on RSPB Ramsey each year. Nevertheless, we believe that these animals only represent around 50% of the total pups born on the island, and that the actual figures could reach between 500 – 760 pups.
So many seals come to pup on RSPB Ramsey Island that they can give birth in the most unlikely – and random – of places. Each year, five or six cows will give birth in the island’s busy harbour, oblivious to boats, people, sheepdogs and quad bikes – with one grey seal even giving birth in front of 40 school children last year! After a big storm, seals can end up on harbour steps and visitors will have to almost walk over them when landing. At this point, RSPB Ramsey Island staff will sometimes use a broom to stop the mothering grey seals from biting visitor’s legs.
When born, pups will weigh an average of 14kg. Yet, when it comes to being weaned at between 16 and 18 days old, and subsequently abandoned by their mothers, the pups will have ballooned to an average weight of 45kg. To achieve this great natural feat, the mothers must provide 2.5litres of fat-rich milk each day to support their growing pup. And to raise their growing brood, mums will use 30,000 calories a day – the energy equivalent of a human eating 285 bananas each day!
Image by Lisa Morgan: Grey seal and her young on RSPB Ramsey Island.
Many of RSPB Ramsey Island’s grey seals are creatures of habit, giving birth on the same beach, on the same day, each year. Some, however, make the decision to move between sites, with some moving onto our neighbouring island over at Skomer. To help identify the same females from one year to the next, RSPB Ramsey Island wardens use a clever piece of ‘spy’ software, where photographs are taken and individual spots and markings are analysed. Then if the same grey seal is spotted again the software would flag a ‘match’, allowing RSPB Ramsey Island staff to discover the animals’ movements outside pupping season. The island’s seals have been spotted as far north as Anglesey and as far south as Cornwall. However, even without the software, RSPB Ramsey Island Warden, Lisa Morgan, can identify over 250 individual seals by eye alone!
The island’s seal breeding season brings many day visitors to the island in the autumn. Our iconic seabirds may have left for winter at sea, but autumn brings hundreds of grey seals to RSPB Ramsey from all across the Irish Sea. For this very reason, RSPB Ramsey stays open until the end of October each year.
For island visiting information until the end of October, please email ramsey.island@rspb.org.uk