A total of 408 pups were born within the Skomer Marine Conservation Zone last year!
With seabird monitoring coming to an end, August might seem like the perfect time for our Skomer wardens Nathan and Slywia to take some time out. However, the island’s Grey seals have other ideas. From the middle of the month pups start to be born on Skomer’s beaches and in the island’s sea-caves and so begins another busy 4 months of fieldwork and monitoring.
Island staff deliver the seal monitoring contract each year for Natural Resources Wales. Together with the Skomer MCZ staff who monitor pup births on the beaches around the Marloes peninsula, they produce an annual report which covers the whole of the Skomer Marine Conservation Zone.
Last year the first pup of the season was born on 9 August at Matthew’s Wick, a deep cove on the Neck. This year the first pup was born in the same place on the same date!
16 pups were born in August 2019, 144 in September, 73 in October and 5 in November.
September clearly remains the peak of the pupping season with a frantic three weeks from mid-month onwards. And the busiest pupping sites, known as rookeries, were South Haven (54 pups), North Haven (42 pups), Matthew’s Wick (39 pups), Driftwood Bay (29 pups) and The Wick (21 pups).
A total of 408 pups were born within the Skomer Marine Conservation Zone last year, of which 170 were born on the Marloes Peninsula.
The team monitor each pup from birth or soon after, following its rapid development from a long, thin newborn to a barrel-shaped, fully-moulted juvenile 3 weeks later. Healthy pups, with attentive mothers should triple their birth weight in this time and this is important. From as little as 16 days old they are weaned and abandoned by the cow, who returns to the sea to feed after a period of fasting since giving birth. The pup is now independent and alone, ready to face the elements and learn to catch and eat solid food for the first time without parental guidance. In 2019, 77% of Skomer pups were known or assumed to have survived to reach this stage.
The survival of pups from birth to weaning and later when they leave the relative safety of the rookery, is highly variable. You will remember the violent autumn storms of October 2017, with ex-Hurricane Ophelia quickly followed by Storm Brian, resulting in high pup mortality across Pembrokeshire’s pupping sites. Although adult seals were able to abandon the beaches and head for the safety of deep water, young white-coated pups on beaches bounded by steep cliffs had no means of escape. We wait to see what the 2020 season will throw at us, but I cannot recall another year with two named storms before the end of August. Luckily, only 5 pups had been born on Skomer as Storm Francis raged last week and they all made it in one piece.