PORTLAND (AP) - Although snow and ice have forced the Oregon Zoo to close its gates to visitors four days this year, the animals inside still need food, warmth and somebody to clean up their messes.

A hearty band of caretakers have braved the winter storm blowing through Portland to reach the zoo's West Hills location, where blustery days provide extra challenges.

When the staff and animals have the zoo to themselves, as they did Tuesday and Wednesday, one of the state's largest tourist attractions loses out on cold cash from visitors. On a typical zoo visit, a person spends $9 for admission, food, special exhibits and souvenirs. A dreary weekday in January draws about 500 visitors, bringing in $4,500; a sunny summer day can attract 3,000 people, Zoo Director Tony Vecchio said.

"I'd rather have our worst January than a mediocre June," he said.

Warm-weather attendance will determine whether the zoo meets its bottom line, Vecchio said. Still, he hates to see the zoo deserted.

Managers decide each morning whether to open based on the parking lot and pathways. Even when weather keeps people away, animals stay put. Zoo animals require basics such as cleaning indoor stalls and feeding, though even those tasks require creativity. About half the usual 21-person keeper staff reported to work Wednesday, some in heroic fashion. One keeper started on foot at 3 a.m. from Northeast Portland; others combined bus, walking and hitchhiking trips.

Once staffers arrive, they don't leave until all the animals are cared for, said curator Jan Steele. Two maintenance workers spent Tuesday night working on frozen pipes, and the crew has pitched in to help keepers. Each animal gets food and a basic stall cleaning, complicating work for keepers who usually put charges outdoors while making the place spick-and-span.

Some animals don't fare well in frigid weather. Elephants' ears are sensitive to frostbite, and if a pachyderm took a spill on the ice, keepers couldn't help it up without special equipment. Tall animals with wiry legs, such as giraffes, are especially prone to slipping.

But leopards, tigers, beavers, otter and elk all thrive in snow. They've been spotted romping in it, though leopards gravitate to their heated rocks, too.

"The ones with outdoor access are very relaxed," Steele said. "They're thinking this is kind of nice. There's no public here, and nobody's messing with them. It's kind of a snow day."