Facts About Sea Lions

From the Marine Mammal Center, California

1. Sea lions are social animals and groups rest closely together on land at chosen "haul-out" sites or float together in "rafts."

2. Sea lions, seals and walruses are collectively called pinnipeds, Latin for "feathered feet."

3. Sea lions feed on squid, octopus, herring, rockfish, smelt and hake.

4. During breeding season, males establish and protect territories, both on land and water.

5. California sea lions are known for their intelligence, playfulness and noisy barking. (Trained "seals" in zoos and aquariums are usually sea lions!)

6. A member of the eared seal family of Otariidae, the California sea lion is "Zalophus Californianus" to scientists.

7. Males are usually darker than females.

8. As male sea lions age, the fur on the tops of their heads (and around their whiskers) gets lighter. Check it out!

9. Grown males reach 1,000 pounds and 7 feet in length. Females can grow to 350 pounds, 6 feet in length.

10. Despite their name, they look more like dogs than lions. (What's more, they "bark" and their young care called pups!)

11. To tell males from females, look for the bump or "crest" males develop on their heads around five years of age. Pier 39's [in San Francisco] visitors are typically males.

12. Killer whales and great white sharks are their greatest natural predators.

13. Sea lions may be mistaken for dolphins when they "porpoise," or jump out of the water, to make faster time swimming.

14. They range along the Pacific Coast from Vancouver to the southern tip of Baja.

15. They usually breed on offshore islands from the Channel Islands to Mexico and occasionally on Ano Nuevo and the Farallon Islands in Northern California.

16. Special contracting nose muscles allow sea lions to seal their noses (useful when diving).

17. Sea lions have external ear flaps, seals do not!

18. They can remain submerged for 10 to 15 minutes, but sea lions are mammals so they must surface for air.

19. Sea lions coexist with Pier 39's marina tenants, thanks to management's thoughtful decision to vacate K-dock, leaving the sea lions undisturbed.

20. Pups are born in June or July.

21. Females recognize their pops on crowded rookeries mainly through smell and vocalizations.

22. Sea lions weigh 12 to 14 pounds at birth.

23. Pups nurse for at least 5-6 months, sometimes up to one year.

24. No one really knows why the first group of mostly male sea lions began "hauling out" on Pier 39's K-dock in 1990, but the abundant food supply and protected environment keep them coming back year after year.

25. California sea lions are various shades of chocolate brown.

26. Sea lions are polygamous. A mature male may breed with 3 to 40 females in a season, depending on his size and strength.

27. Sea lions are warm-blooded animals with a thick layer of blubber under the skin, to insulate them against the cold.

28. Sea lions tear profusely to cleanse their eyes of excessive salt and other impurities. They don't cry.

29. Sea lions in the wild may live up to 18 years. Those in captivity have been known to live 23 years or more.

30. Sea lions can swim up to 25 mph in short bursts.

31. They often dive to depths of 360 feet, sometimes to depths of 800 feet.

32. Since they're animals of habit, it's a good bet (but not a sure thing) that the sea lions will keep returning to Pier 39.

33. California sea lions are protected by the Marine Mammal Protection Act. It is unlawful for unauthorized persons to feed, handle of harass them.

34. Like humans, sea lions can develop diseases such as pneumonia, cancer and epilepsy.

35. One of the biggest dangers to sea lions today is becoming entangled in plastic pollution.

36. Sometimes a spotted harbor seal will haul out with the sea lions who always rest a few feet away, giving the seal "its space."

37. Sea lions will bite if provoked.

38. If you see a California sea lion or other marine mammal that seems to be in distress, call the Marine Mammal Center at (415) 289-7325.

39. You can help sea lions (and seals and sea otters and whales and dolphins) by becoming a member of the Marin Mammal Center. Write to them at the Marin Headlands, Golden Gate National Recreation Area, Sausalito, California, 94965 or call (415) 332-5080.

Sea lions and seals are not the same thing. However, both are present along the California coastline. Three of these are protected and on the endangered species list: the Steller sea lion, the northern fur seal, and the Guadalupe fur seal, all of which resemble California sea lions.

Sea lions and seals are all protected under the Marine Mammal Protection Act, which says it is not acceptable to use lethal action against these animals unless they pose an immediate danger to one's catch, gear or person -- and even then, it is only allowed after all non-lethal methods have been used.

Animals like Steller sea lions are fur seals are endangered and may only be killed if they pose a direct threat to someone's life.

A popular myth is that killing seals is the only way to prevent them from eating one's catch. However, loud noises used properly can deter sea lions, and other sound devices are being developed to make fishing boats unattractive to these animals. Also, fishing crews should hang onto unwanted fish or parts rather than throwing them overboard -- as these fish attract sea lions and seals.

Likewise, it is not easy to kill a swimming seal or sea lion -- people believe a gunshot is a quick and humane way to kill these animals, but many are maimed or blinded and die slowly. These animals eventually wash up onto shorelines.