What’s the difference between seals and sea lions?

The confusion between the two comes from the fact that they are both pinnipeds (fin-footed, carnivorous marine mammals). However, seals and sea lions are in fact two separate families called Phocidae and Otariidae. The only other pinniped family is Odobenidae, of which the only living species left is the walrus.

A distinctive trait to differentiate the two is whether they have visible ears. ‘Earless’ seals (Phocidae) do not have external ear flaps. However, ‘eared seals’ (Otariidae), such as sea lions, do. Seals are generally smaller than sea lions - though there are exceptions to this, like elephant seals which can weigh up to 4,000 kilograms!

The way they move out of the water is also very different. Sea lions have larger front flippers than seals. As such, they are generally much more confident and agile walkers on land than seals. They can rotate their hip bones and support their weight so that they push off the ground and almost gallop.

Sea lions are incredibly social animals and are known to be very noisy, as well as smelly when they gather on land. They make barks and grunts to communicate with one another.

Seals are much quieter than sea lions but are also known to gather on land with one another. This is generally to rest, moult and avoid predators such as Orcas, sharks and even other seals like leopard seals.

During mating season, seals become more social and will gather in small groups to find a partner. Though seals may attack one another over a single female, their fights are generally less aggressive than sea lions - though as always, there are exceptions to this.

On the other hand, male sea lions or bulls are highly territorial during mating season. They form large breeding colonies where they compete for dominance against one another in order to claim their right to mate with a group of females throughout the season.

If you live in the UK then there is one vital thing between knowing the difference between seals and sea lions: sea lions are not native to our shores. Beach walkers will not see any groups lazing around our coast like they might at Pier 39 in San Francisco. On the other hand, the UK is home to two species of seal, the harbour (common) seal and the grey seal.

These species of seals can be found across all four nations that make up the UK from the Moray Firth in Scotland, the Pembrokeshire coast in Wales, Blakeney Point in England and Strangford Laugh in Northern Ireland.