Wednesday, March 16, 2011

A sea lion at the pier near the Crissy Field Warming Hut

A sea lion consumes from 15 to 20 pounds of fish a day [1]. This one is looking for fish in the San Francisco Bay around the pier east of Fort Point near the Warming Hut. There are people fishing here and maybe some fish will slip off the pier. This sea lion is begging for it.

Sea lions, like other pinnipeds, typically show well-developed cognitive and learning abilities. Our friend here probably associates the presence of human beings above the water surface with the occasional drop of fishy remains. Although some sea lions are afraid of people, this one enjoys watching them. Biologists refer to this behavior as habituation. For example, Zalophus on some Galápagos Islands is rarely frightened by people [2]: Sea lions on islands in the Galápagos frequently visited by people seem to be more tame than those inhabiting the less accessible, more remote islands. At the Golden Gate, sea lions have to get used to surfers and boat traffic and fishermen are their friends (although not vice versa). Further out at sea, around the Farallon Islands their attention surely will focus more on sharks.

References and further reading
[1] Tom Stienstra:
California WildlifeA Practical Guide. Avalon Travel Publishing, Inc., Eneryville, California, USA, 2000; pp. 332-336.
[2] Marianne Riedman: The Pinnipeds
Seals, Sea Lions, and Walrusses. University of California Press, Berkeley, 1990; page 315.

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