Sea Lions Slowly Return to San Francisco's Pier 39

Sea lions are returning to San Francisco's Pier 39 after an abrupt disappearance that left tourists disappointed and experts baffled.

The number is fluctuating. But the population appears to be making a slow return after mysteriously ballooning to about 1,700 during Thanksgiving week, then dwindling to a handful in the following days.

Jim Oswald of the Marine Mammal Center says a couple dozen sea lions were lounging Tuesday on the floating docks.

Marine experts say the animals come and go regularly, leaving in the fall to breed and give birth to their young in the Channel Islands.

Oswald says the large numbers seen in November, and their sudden departure, were unusual but not worrisome. He says they were probably looking for food.