Grey seals are a joyous sight in Scottish waters. RSPB Scotland’s Rebecca Lianne Shaw, one of our fantastic Dolphinwatch volunteers, shares five facts about these wonderful creatures.  

Five facts about grey seals

1. Whose nose is it anyway?

Grey Seals are pretty distinctive from their cousins, the Common seal. While Common seals are known for being the ‘Labradors of the sea’, with their characteristically squashed heads, adorably round large eyes and distinctive V shaped nostrils, grey seals do not get awarded such a cute nickname. In fact, their scientific name ‘Halichoerus grypus’ can be translated to “hooked nose sea pig”. Often referred to as a roman nose, grey seals do exhibit a largely prominent nose with a wide set of parallel nostrils. This species also demonstrates sexual dimorphism - the bulls are not only bigger in body size but have longer noses than the females. This can make it quite easy to distinguish who is who in the water.

grey seal bull on sand
Grey seal, adult bull moving up a sandy beach. Ben Andrew (rspb-images.com)

2. Baby, baby, baby

Grey seals come to shore at various sites across the UK coastline, in seal terms these are known as haul out sites. Some of these areas are designated sites – such as the Ythan Estuary in Aberdeenshire, which attempt to avoid human disturbance to the hauled-out seals. Anytime between September and November, female grey seals will haul out in preparation for the breeding season. A female will normally have just one pup which will stay with its mother for around three weeks. As the pup does not have an insulating layer of blubber yet, it is born in a fluffy white fur known as lanugo. This keeps the pup nice and warm whilst learning from its mum during its first few weeks of life. It will normally shed the fur between 27-29 days after birth when they then moult into an adult pelage, or what we’d more commonly refer to as a coat.

newborn seal pup lying on back
Grey seal, newborn pup sleeping upside down on beach. Ben Andrew (rspb-images.com)

3. Fasting for the Future

During the winter months of the breeding season, both male and female grey seals will congregate on haul out sites with males typically coming to shore later than the females. They are what is known as ‘capital breeders’ – they will reproduce using only energy that is stored in their blubber reserves. This means that they will fast for the duration of the breeding period, which can be up to 20 days for females and 50 days for males. During this period, you can notice that the seals will display a lot of ‘resting’ behaviour to conserve their energy stores!

several seals lie on beach
Haul out, Ythan Estuary. Rebecca Lianne Shaw.

4. Deep Sea Divers

When not spending time onshore, seals are normally offshore foraging for food. A grey seal’s diet largely depends on what species are available in their surrounding environment, but around the UK coastline common prey species are sandeels, whiting and flatfish. They are therefore known to dive, as these prey species are benthic dwellers meaning they are usually found on the bottom of the seabed. Seals are known to be built for diving and do so at a wide range of depths ranging from around 50 metres up to an incredible 300 metres!

5.Threats

Despite having a healthy population of Grey Seal’s residing around the UK’s shorelines, estimated to be 150,000 individuals in 2018 – making up 40% of the world’s population - they are still suffering from a wide variety of threats. Overfishing of prey species, marine disturbance and illegal shooting are some of the pressures that threaten the integrity of the population. However, one issue that is very pressing within the current climate is that of pollution. Seals across the UK are being affected by the plastic plight, with entanglement being one of the main welfare reasons worrying conservationists.

It is not only the large pieces of plastic that we are seeing affecting populations, but also the smaller microplastics that are causing harm. Nurdles are small pieces of plastic (less than 5mm) that scatter the lining of our beaches’ sands across the UK in their thousands. Ingestion of these small pieces can cause blockages and accumulation of toxic chemicals. It is estimated that at least 53 million nurdles enter the British seas each year.

You can help our fight against the plastic pollution by safely collecting rubbish you find around your local area, taking part in a great nurdle hunt or by joining an organised beach clean when it is safe to do so again.

Click here to watch our grey seal favourite facts video with RSPB Scotland's Niamh Byrne.

Anonymous