When is a seal not a seal? The case of the Galápagos Fur Seal

In the world of Pinnipeds (carnivorous, fin-footed, semi-aquatic marine mammals), there's more than meets the eye.  The most common pinnipeds are seals (phocidae) and sea lions (otariidae), however it turns out that the Galápagos Fur Seal however is not actually a true seal. 

Galápagos Fur Seals, like similar fur seals elsewhere are not actually true seals (phocidae). They are actually the smallest members of the otariidae family, meaning they have external ear flaps, like their larger distant-cousin, the Galápagos Sea Lion.  So, technically, it should be referred to as a Galápagos Fur Sea-Lion, but that just gets confusing.  So why is it called a seal?

Primarily, it’s due to the observable differences in shape and size.  Galápagos Sea Lions have dog-like heads with pointy snouts, whereas Galápagos Fur Seals have shorter, blunter muzzles and larger eyes. Galápagos Sea Lions have much longer slimmer necks, whereas the Fur Seal has a short, thick neck, almost indiscernible from the rest of its body. The major difference between the two species is that sea lions have a single coat consisting of short coarse hair, whereas the fur seals have a dense under layer of fur in addition to the coat of coarse hair. That is why they are locally referred to as “dos pelos” meaning two coats or skins.

Galápagos Fur Seals live a more solitary existence and prefer spending more time at sea. When they do come ashore, they are found primarily on rocky coastlines. Sea Lions by comparison are far more social, living together in large "rafts", and prefer to spend their time ashore on sandy beaches. Both Galápagos Fur Seals and Sea Lions give birth to a single pup at a time, and feed on fish and cephalopods. Fur Seals can dive extraordinarily deep, and have been observed at depths exceeding 550 feet. Despite this, they are extremely susceptible to the effects of El Niño, when warm waters decrease the sardine population and push the thermocline and their cephalopod (squid, cuttlefish, octopus) food source far deeper.

At one time, Galápagos Fur Seals were hunted to near extinction. Due to bans on hunting, populations are now stable and rebounding. Despite this, they are still found in far fewer numbers than their Sea Lion cousins.  You will likely encounter Fur Seals on eastern route around the rocks surrounding Prince Philip Steps on Genovesa (Tower) Island.  On the western route, you will have the opportunity to get much closer to observe them at Puerto Egas, on the western coast of Santiago Island.