After pulling on waterproof overalls, Jane Tollini rolls out a small plank at the San Francisco Zoo and walks across to Penguin Island. Her 52 tuxedoed charges need a big breakfast of smelt and herring before the throngs of curious onlookers descend to catch a glimpse of the city's latest celebrity exotics.
Tollini sings a little ditty to a penguin she named Grubby to get him to eat his glucosamine-spiked herring. (Yes, penguins have joint problems too.) Taking a pause from her crooning, the zookeeper says, "You know how cowboys sing to their cattle, I sing to my penguins. It's common."
Tollini is mother hen to the colony of Magellanic penguins that has captivated and mystified experts and penguin lovers around the world with their strange behavior of late. Like their migrating brethren in the wild, the San Francisco birds have been swimming nonstop for weeks, barely pausing to sleep or eat.
It all started on Christmas Eve, when six penguins from Sea World in San Diego were introduced to the verdant outdoor concrete pool that had been home to the penguin colony since 1984.
The San Francisco penguins had grown used to the easy life at the zoo. Free food, free health care and Tollini's loving attention made them so lazy that they rarely even made it to the edge of the island to jump in for a swim. "It's like we give them room service here," Tollini says, adding that the birds long ago realized there was no need for migrating any more.
But the six new penguins changed that. They came from a colony that had retained their migratory habits despite captivity. When the new birds moved into the Penguin Island exhibit, they started swimming almost immediately. After about an hour the rest of the birds followed suit. They have been swimming ever since.
Magellanic penguins are native to South America and live in coastal areas of Argentina, Chile and the Falkland Islands. They also are known as "jackass penguins" -- not for their demeanor, but for the mule-like braying call with which they communicate.
Every year the birds, which stand 18 inches tall, weigh about 8 pounds and pick mates for life, make a 2,000-mile migration before settling into their breeding burrows in February.
Since Christmas Eve, all 52 birds have been trying to re-create their migration in the 130-foot-by-40-foot pool.
They are very determined. When keepers drained the pool for a routine cleaning, the birds jumped in and walked in circles. They weren't going to stand for "migration interuptus," Tollini says.
Public interest in the colony has only grown with each quick lap around the island.
Word got out of the ceaselessly swimming critters and now the birds -- identified by Tollini with names like Don Vito, Filthy and Ravioli -- have been featured on at least 288 television news programs across the country, says Nancy Chan, the zoo's public relations director.
Chan says she has received e-mails and phone calls from around the world, including a note from a man in New Jersey who believed that the penguins' behavior could be a sign that a major earthquake is about to occur. The added attention has brought hundreds of people to the zoo, and has left experts and amateur penguin enthusiasts befuddled and searching for an explanation.
Watching Saturday as several dozen of the birds "porpoise" or jump out of the water while swimming fast, Gracie Wade of San Jose, wonders about the endless swimming. "Did this just sort of click a switch in their brain that said, 'Oh yeah, we're supposed to do this?' "
Nearby, Steve Lafond waxes philosophical on the futile migration of the captive penguins. "It's endless swimming to nowhere," he says. "It's pretty cool."
Lafond's 10-year-old daughter, Corie, however, is more interested in the nearby sea otters. She says she likes them better because, as opposed to the introverted penguins, the otters "actually want to know what goes on outside the glass."
Peter Shannon, the zoo's associate curator of birds, says he is at a loss to explain the penguins' behavior.
"We don't know why the introduction of the six new birds changed the entire colony's behavior," he says while watching 10 birds dart effortlessly through the water.
Ken Ramirez, director of training and husbandry at Chicago's Shedd Aquarium, calls the media frenzy surrounding the birds "a lot of hubbub." He thinks that the San Francisco penguins are now just doing what they normally would be doing in the wild.
"It's a natural time for them to swim," he says, adding that the arrival of the new penguins "might have triggered some natural instinct."
Wendy Turner, curator of birds at Sea World, says that, being typical San Franciscans, the northern birds were just really laid back until the "San Diego Six" came along.
"They were just used to hanging out on land," she says, hinting at a slight aquarium rivalry between Sea World and the San Francisco Zoo. "When they went up there they said, 'This is great, we can swim forever in it.' The San Francisco penguins followed our birds."
With an exasperated look on her face, Tollini says she is at a loss to explain the phenomenon in any scientific way. "All you can do is hypothesize. Six convinced 46 to do it when, after 19 years, they didn't have a clue to do it." Her only explanation is simple, and typically San Franciscan. "I think they have been reintroduced to their inner penguin," she says.