Graceful acrobats under water, the California sea lions and harbor seals play as they would in the wild in the 225,000 gallon pool on the zoo's main mall.

Although awkward on land, these marine mammals have streamlined bodies perfect for diving, swimming, and taking those underwater curves at high speed.

Harbor seals can dive as deep as 300 feet and stay submerged for more than 20 minutes.But they do not lead a completely aquatic life as both seals and sea lions must return to land to give birth and nurse their young.

The differences between these two gregarious mammals are most apparent on land. Sea lions have four well-developed flippers: two front ones that power them through the water and support the body on land, and two hind flippers that rotate forward beneath the body so they can "walk" on shore. Harbor seals have much smaller foreflippers and broadly-webbed back flippers that more closely resemble a tail. On land, seals "crawl" on their bellies.

A closer look reveals another difference; while sea lions have small external ears, harbor seals do not have ears you can see. Both animals, however, can hear quite well.

 

California sea lions are found off the rocky west coast of North America and around the Galapagos Islands. Harbor seals are more widely distributed in northern Atlantic and northern Pacific regions, generally living around ocean shorelines and islets.

Both are insulated with a thick layer of blubber to stay warm in chilly sea waters. Lincoln Park's Sea Lion Pool is maintained between 40 and 46 degrees Fahrenheit. The fat also contributes to their boyancy and provides extra energy during fasting and nursing young.

Seals and sea lions are carnivores, eating fish and shellfish. Their large eyes are especially adapted for low light conditions and clear viewing underwater. Long whiskers may be used in murky water to detect from fish swimming by. Killer whales, sharks and man are among their predators.

Species data sheets:

Photos at left © James P. Rowan Photography

Photo above © Greg Neise