Seals and Sea Lions: An Affectionate Portrait (Marine Life)

What are Pinnipeds?
"Pinniped" - meaning "feather-or fin-footed" - describes a family of chubby marine mammals often lumped together as seals. The family includes walruses, eared seals such as the sea lion, and earless or "true" seals. In this book, we'll be looking at the pinnipeds most often seen along the Pacific coast of North America: harbor seals, California seal lions, and northern elephant seals.

About 25 millions years ago, the first eared seal made its appearance, having evolved from a bearlike ancestor. (True seals came somewhat later by was of an otterlike ancestor.) Today over 30 species of pinnipeds live in nearly every ocean of the world. These pinniped cousins have distinct looks and lives. They can be as massive as an 6,000-pound southern elephant seal, or as small as a 125-pound ringed seal. Some are quiet, other, non-stop vocalizers.

What do these family members have in common? First, they are comfortable in two worlds: on land and in the sea. They share a common body shape - muscular, sleek, well-padded with blubber. With these flippered bodies, pinnipeds flash through the water with acrobatic grace and speed. On land, we often find their movements amusing, but they don't do badly here, either. Some seals can slide 100 feet a minute on their bellies. There are two-ton pinnipeds that can climb steep sand dines - even cliffs. Depending on species, pinnipeds haul out on land to rest, mate, to give birth, to nurse pups, and to molt.
-from the Introduction