Seals have a perfectly streamlined body – nothing sticks out in a way that could hinder them from gliding through water. There seems to be something missing from their round, smooth, head though. Where are the ears? And if there are none, how can seals hear? Do seals have ears?
Yes, they do! Just because you cannot see something does not mean that it is not there. Seals simply do not have external ears that can be seen from the outside, but when you get close enough, you can see the tiny holes at the sides of their head. The inside of their ears looks like those of other mammals, though.
Seals can hear much better underwater than above water. On land, their hearing is similar to other mammals, although a bit less receptive. A reason for this is that their ear canals, which are particularly long, are often blocked by wax, and unlike humans, they cannot simply go to the ear specialist and get it cleaned out.
All in all, their lack of external ears does not make a big difference compared to other mammals when it comes to hearing above water. The underwater hearing skills of seals are much more impressive, though. Their lack of pinnae – the scientific name for the part of the ear that is visible from the outside – makes them much better at picking up from which direction a sound comes than animals that have ear flaps.
How Do Seals Navigate?
Aside from their sense of hearing, what are the other methods seals utilize to find their way around? Especially seals living in the Arctic or Antarctic must have impressive skills, since they largely live under ice and have to locate their breathing hole regularly. It is theorized that they use visual landmarks like the light shining through thin or thick ice, to find their way. They also seem to have an excellent spatial memory and are presumably able to remember routes that they swim often very well. Other researchers pose the theory that seals use the magnetic field of the Earth to find their way.
In clear waters where they do not have to find their way under the ice, seals even use the stars to navigate! Harbor seals have impressive visuals skills and experiments have shown that they are capable of identifying single specific stars out of a projection of the Northern Hemisphere night sky.
Why Do Seals Slap Their Bellies?
Slapping their bellies is a means of communication for seals. Since they are able to hear sounds with a really low frequency, they can hear a belly slap even underwater. Additionally, it is also a tool of visual communication, and this gesture can display aggression or be used in courtship.
What Are the Differences Between Seals and Sea Lions?
Sea lions and seals look quite similar, and they both belong to a group of marine mammals called pinnipeds, meaning fin-footed or flipper footed. This group contains three families: the true seals, sea lions (or fur seals), and walruses. While most people are able to recognize a walrus when they see one, given its size and its impressive protruding teeth, the differences between seals and sea lions are less obvious.
Only true seals, though, do not have ear flaps, which means that when the animal you are looking at has pinnae, this means it must be a sea lion.
They also look very different when they move on land. Sea lions have large front flippers, and when they are on land they walk on all four of their flippers. Seals, on the other hand, have smaller front flippers, and on land, they move by flopping along on their belly.
At sea, seals propel themselves through the water by moving their back flippers back and forth like the tail of a fish. Sea lions, on the other hand, paddle with their front flippers and use their back flippers to steer.
Sea lions are also much louder than seals. They communicate in barks that can be heard over long distances, whereas seals produce softer grunts.
Lastly, sea lions tend to congregate in groups – a herd can comprise about 1,500 animals! – whereas seals are more solitary.