PORTLAND, Ore. — If you think your kids are real animals when it comes to breaking toys, consider the problems facing the nation's zookeepers who must find ways to entertain lions and tigers and bears.
Consider Gordon Noyes, whose job is to find playthings that will stand up to the antics of Conrad and Yugyan, two 1,200-pound polar bears at the Washington Park Zoo.
"They like to try to sink their teeth into toys," said Noyes, a zookeeper for nearly 25 years who has spent the last 15 of those taking care of the bears.
Noyes must find playthings for the bruins that are hard enough to withstand the bears' bites, yet soft enough to bounce off the glass windows surrounding their enclosure.
"We used to buy chipped bowling balls for the bears, which they really liked. But with the glass windows in the new exhibit area, we can't do that anymore," Noyes said.
The bears like toys that are moveable, that they can control, he said.
He has been experimenting with different types of balls and floats to see which ones the bears prefer. Although he's learned plenty about the punishment his charges can hand out, he hasn't yet determined if the bears have a favorite toy, or what that might be.
"The males like large floats they can jump on," he said. "But the females can get intimidated by the big ones, so we'll put in some smaller floats. Our youngest female was very timid at first, but has come to enjoy playing with things."
Noyes said several toys are given to the bears at the same time to avoid fights. For Yugyan and Conrad, fewer than four toys can lead to an argument. He also withholds a toy for a day or two so it will seem new and interesting.
Bruce Brewer, assistant curator of mammals at the Brookfield, Ill., zoo said he also tried, and rejected, used bowling balls.
"We got some bowling balls made without holes so the animals wouldn't break their teeth on them. The polar bears thought they were terrific, but we had to take them away when we discovered the balls were the perfect size for plugging the drains in their moat," Brewer said.
The balls proved just as problematic for the lions. One male liked a ball so well he adopted it and refused to let the females near it for two days. The big cats also took to batting the balls back and forth and bouncing them off the walls of the cage, which left holes, Brewer said.
The zoo now uses aluminum beer kegs in the polar bear exhibit. Since the kegs float, the bears can jump on them or bat them back and forth with their paws. The kegs haven't plugged the drain yet.
Although many zoos have had to use unlikely objects from other industries as toys, that trend is changing. Joan Schultz of Grayslake, Ill., decided to start her pet toy business, Boomer Balls, after she had trouble finding playthings that would stand up to her bull terrier, Boomer.
"Other people had marketed the balls as toys for pigs being raised in confinement, but farmers found it was cheaper to sacrifice a pig once in a while than to buy toys for distraction," Schultz said.
Schultz first marketed the balls to the show-dog industry. Within a few months, she was selling the toys through local pet shops and looking for ways to expand the business. The zoo market offered a unique solution.
"Some people feel putting toys in a zoo exhibit detracts from the natural beauty of the animals. But often animals without something to do will just lay around. The balls help show off the activity of the animals," she said.
Boomer Balls are available in 10-, 7- and 4 1/2-inch diameter sizes, with plastic an eighth of an inch thick. The 10-inch ball also is available in a three-eighths inch thick model.
Schultz said she guarantees the balls against puncture for one year, and replaces any that are chewed through. In two years of sales, only balls used by pit bulls have been returned.
"The pit bulls have a way of getting their jaw on the ball that is really tough on it," Schultz said. "Once they get a hold on it, they use a can opener motion that just destroys it."