The penguins at Asahiyama Zoological Park in Asahikawa, Hokkaido, have gained weight lately, for good reason.
It's too cold to swim.
"Asahikawa is actually too cold for these penguins, so they stop swimming in the pool in winter," Asahiyama zoo spokesman Takehiro Nakata said in a telephone interview. "But they are fed regularly so they need exercise."
King and Gentoo penguins are used to temperatures of about minus 10, but the mercury sometimes drops as low as minus 18 in Asahikawa, Nakata said.
That's why the zoo began its famous Penguin Walk in 2002, Nakata said. Forcing the birds to walk outside their protected pen gives them much-needed exercise.
"The walk is partly to maintain their health," Nakata said. "But it is also in their nature to walk long distances to obtain food."
The Penguin Walk is one of the most popular winter attractions at the zoo, which is arguably the most popular one in the country.
This season's walks began Friday with 15 to 16 King and Gentoo penguins strolling along a 500-meter snow-covered promenade in full sight of visitors.
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