Cornwall Mammal Group
Conservation:
Grey seals are one of the rarest seal species with about 35-50% of the world population
found in UK waters. The UK has special responsibility for the grey seal under Annex II of the EU Habitats Directive. All seals are protected in the UK under the Conservation of Seals Act (1970) although shooting of seals is permitted under certain conditions where conflicts with fishing interest occur. Grey seals are a key species in the Isles of Scilly SAC designation. The Seals Protection Group is actively campaigning for more comprehensive protection for seals.
Recognition:
gREY seal-(Halichoerus grypus)
Order: Carnivora, Cornish Name: Ruen
The Cornwall Seal Group has developed an extensive database, from many years of
observation and photography, which allows around 1000 individual grey seals to be
recognised. This has enabled the group to study seal movements between Cornwall,
Wales, Ireland and France and to
demonstrate how the animals use many different sites over the year. This information is critical to planning
conservation at a regional scale. The Cornish Seal Sanctuary, at Gweek, near Helston, has been rescuing, rehabilitating and releasing seals around the Cornish coast for more than 50 years.
Distribution:
Grey seals have been recorded all around the Cornish coast and the Isles of Scilly. They occur around the UK but with the strongest populations in western Scotland. Worldwide they are limited to the North Atlantic and the Baltic with two apparently separate populations in the eastern and western Atlantic.
Records:
2007-2012: 1779
2002-2007: 1768
Pre-2001: 1407
Total: 4954
The grey seal is the most commonly seen seal around Cornwall’s coast. They range in colour from white to black and from cream to chocolate brown. Unique fur patterns allow individuals to be identified. The large doglike head with a Roman nose is clearer in adults. They have large, dark eyes and closer up the
long, sensitive whiskers and parallel nostrils can be seen. The fore flippers are webbed and have 5 long claws, each of the powerful rear flippers is also tipped with 5 claws. The grey seal is the UK’s largest land-breeding animal and males can reach weights of 350 kg and be up to 2.8 m in length. They tend to have plainer and darker fur patterns and the ‘roman’ profile of the nose is more pronounced. Females have shorter, narrower faces and lighter coats with more spots; they may reach 2 m in length and 250 kg in weight. Pups are around 1 m long at birth and covered in long cream or white fur for the first 3 weeks, which then moults to reveal their permanent adult coat
pattern. Occasionally a common seal may haul out alongside groups of grey seals. Common seals have shorter, snubbed noses and broader foreheads, more circular when face on than the oval face of the grey seal. Closer to, the grey seal’s nostrils are almost parallel, whilst those of the common seal are more ‘V’ shaped.
Although grey seals are most often seen on the beaches and around the coast, research by the Cornwall Seal Group has shown that individuals travel widely around the coasts of Western Europe. The seals need 4 distinct habitats—sheltered and inaccessible beaches and islands where they can pup and haul out to moult and rest, sea caves with areas above high water where the pups are born, feeding
grounds of open seabed up to 120 m deep, and open water
connecting these habitats. Their preferred prey is sand eels, but a wide variety of other fish species is also taken and a typical seal consumes about 5 kg/day.
Grey seals come ashore all year round but the largest groups are seen in the spring during the moult, and in the autumn as they assemble at traditional pupping sites controlled by dominant ‘beachmaster’ bulls. After mating the fertilised egg does not implant for up to 3 months and the single pups are mostly born between September and December in Cornwall. The mother feeds the pup a rich milk for the first 3 weeks of its life and during this time it grows from 10 kg to 40 kg. Pup mortality is relatively high and dependent to a large degree on weather and sea conditions during the early months. Males are sexually mature at 4-6 years but are rarely successful in competing for access to females before 8-10years. Few males survive beyond 25. Adult females breed at 6-8years and may live to 35, the oldest recorded being 46!
The only natural predator of the grey seal is the killer whale.
Deliberate killing is rare in Cornwall out animals may fall foul of fishing gear and litter—many seals around the Cornish coast have injuries from net entanglement and fishing lines.
Did you know?:
Grey seals breathe out when they dive; the average dive lasts 12 minutes and can reach depths of 120 m. The seals’ nostrils are relaxed when they are closed: they contract muscles to open them. In gaelic mythology selkies are grey seals that shed their skin to appear as humans. The scientific name means hook-nosed sea pig.
Survey Methods:
Coast walk transects and boat surveys. Photographic ID allows individual seal movements to be monitored. Grey seals favour particular sites, which can be monitored. Stranding records,
especially of pups, allow more detailed recording.
Tracks and Trails:
Seals may leave trails in the sand when they haul out of the water, clearly showing the clawed front flippers either side of the drag marks from their body. When haul out sites become crowded their howls, growls and snarls may be heard from the cliffs and their strong, sweet musky smell may be detected.
