>BBC
>Friday, 17 January, 2003, 11:36 GMT
>Penguin puzzle perplexes US zoo
>
>
>The penguins swim en masse from dawn to dusk
>
>Penguins have become involved in a marathon swimming session at San
>Francisco Zoo.
>Feathers appear to have been ruffled when six new birds were introduced to
>the colony in November.
>
>Somehow these animals showed they are worthy of being followed
>
>The newcomers from Ohio took to the pool immediately and the other 46 joined
>in.
>
>But instead of occasional dips, the penguins started swimming frenzied laps
>of the pool from dawn to dusk.
>
>Nothing has deterred the birds: when zookeepers drained the pool for
>cleaning, they simply jumped in and waddled around the bottom.
>
>Migration theory
>
>Some experts believe the arrival of new birds from Ohio may have confused
>the existing colony of Magellan penguins.
>
>One theory is that they are trying to migrate as penguins would in the wild.
>
>
>The birds come out of the pool to grab food and then go straight back in
>Magellans typically travel up to 2,000 miles (3,200 kilometres) in search of
>food, but captive birds have not shown this type of behaviour before.
>
>Another possible explanation is that the new birds set an example to be
>followed by the others in their repeated laps of the 130-foot (40-metre)
>long pool.
>
>Ian Hiler of the Audobon Aquarium of the Americas told the San Francisco
>Chronicle newspaper: "Usually there are one or two dominant birds.
>
>"Somehow these animals came up and showed they are worthy of being
>followed."
>
>Behaviour change
>
>Keeper Jane Tollini has looked after penguins for 18 years, but she is
>baffled by the apparently bird-brained behaviour.
>
>"The minute the six hit the pool, not only did they get in the pool and stay
>there, they convinced the other birds to do likewise," she said.
>
>They see me, see the fish, run past me, grab the fish and keep going
>
>"We've lost complete control."
>
>The marathon swimming sessions are a marked change for the San Francisco
>penguins.
>
>They used to line up to collect fish from Ms Tollini, who can tell them
>apart and has a name for each one.
>
>"I am kind of like a drive-through restaurant now," she said.
>
>"They see me, see the fish, run past me, grab the fish and keep going."
>
>The phenomenon could be nearing its end, however.
>
>Ms Tollini thinks there may be a return to the old routine next month, when
>the onset of the breeding season may lure the birds back to their burrows.
>