In A Nutshell
Even though they belong to the same order of mammals, seals, and sea lions have a very different physical makeup. From their fins to their ears, seals and sea lions look different at a glance once you know what you’re looking for. They also have a very different social and family dynamic, and even sound very different. Seals tend to spend much of their time alone, while sea lions are happiest in large groups of hundreds of individuals.
The Whole Bushel
Seals and sea lions belong to the same sub-order of marine animals (that also includes the walrus) called Pinnipedia. Pinnipedia means “fin-footed” and refers to the flippers that are distinctly different between seals and sea lions. Sea lions have large, powerful front flippers that they use while swimming to power themselves through the water. They steer with their heads and bodies, letting their flippers do the heavy work. Their front flippers are also strong enough to support their weight while they are on land, allowing them to essentially walk on all fours and making them much better adapted to land life than seals are. Seals, on the other hand, have short, stubby, and relatively weak front flippers that can’t support their weight well on land. When on land, they’re forced to wiggle along like a caterpillar instead of walking. And in the water, they use their stronger rear flippers to move them along, and their short front flippers to steer.
Sea lions have distinctive ear flaps on the sides of their heads, while seals have no outer ear structure. A seal’s ears are only tiny holes on the sides of their heads that are invisible from any real distance.
Seals are generally the more soft-spoken of the two, though things can get a little loud when males are competing for territory or females. Most of the time, seals speak only in soft grunts. Sea lions have a much wider range of vocalization, barking, grunting, and growling at each other. Females often talk to their young, and can both recognize and find their offspring by the sound of their voice.
Seals are much more solitary creatures and spend most of their time in the water, where they are much more comfortable and will hunt alone. When they do come to land for an extended amount of time, they often number in the thousands and it’s usually only during breeding season. Sea lions live in huge groups that contain hundreds of individuals. They are often seen “hauling out,” laying on land together and enjoying the sun. Even when there’s no suitable spot available, they congregate in groups in a unique behavior called rafting. Rafting sea lions will gather together to rest in a massive, floating group.
Sea lions, in line with their more communal nature, undoubtedly have the more doting mothers. Females give birth in the summer to a single pup that will continue to nurse for anywhere up to a year. Even though they can eat solid food by the time they’re three months old and can hunt and swim with the adults at two months, they’ll stay with their mother until they’re a year old. Seal mothers abandon their single pup three weeks after birth, leaving the baby on the beach and going in search of another mate.
When it comes to staying underwater, sea lions far outclass their heavier cousins. Sea lions can stay beneath the water for up to 40 minutes and have been known to dive to depths of up to 180 meters (600 ft). The maximum dive time for a seal is only about 16 minutes underwater.