Zoo food au naturel a treat for animals
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WASHINGTON — The tiger speared his prey with a claw and dragged it across the grass. The animal ripped it open, inhaled its scent, chewed its innards. Sniffing the air around him, he dived in for another helping.
The prey actually was a frozen ball of animal blood wrapped in burlap, and keepers at the National Zoo threw it to their male tiger, named Rokan, to offer him a more savage feast than his usual ready-to-eat diet.
Behind Rokan's unusual meal is a concerted attempt by zoos to introduce more of the wild side into captive life. Some facilities, pushing this idea to its controversial limit, feed roadkill to their carnivores in public view.
At the Folsom City Zoo in Northern California, cougars, wolves or bears can spend days consuming a dead deer. They pluck its fur, gnaw its bones, stash it in trees for safekeeping. The animals like the activity so much that the zoo feeds them carcasses to calm them during fireworks shows at the park next door.
The National Zoo, which has debated carcass feeding but not pursued it beyond that, received a taste of how it might work a few years ago when a white-tailed deer jumped into the cheetah enclosure. No one witnessed the event, but the partially eaten carcass was there for all to see when the zoo opened Nov. 5, 1996.
"Some visitors saw it and were upset," recalled John Seidensticker, senior curator of mammals. "It was removed. I would have argued to keep it, at least let (the cheetah) have it."
Although rejecting carcass feeding for now, the zoo employs a variety of other activities to encourage wild behavior. Keepers hide food under leaves or inside hollow tubes to make it harder to get. They place perfume samples or urine of other animals inside cages to stimulate exploration. They give their animals puzzles to solve and toys with which to play, similar to those available for household pets.
Adding these "enrichment activities" reflects cultural changes in zoos, where animal rights and welfare have a growing role. Beginning this year, U.S. zoos must provide enrichment experiences for their animals or lose accreditation.
"Animals are evolved in the wild to finding food, finding mates and defining territory," said Benjamin Beck, associate director of the National Zoo. "They come to the zoo, and we solve all those problems for them. What we are doing with enrichment is simulating the challenges they would face in a wild environment."
At the Folsom City Zoo, keeper Lee Houts said exploring, guarding and eating a carcass give animals a challenge and purpose on which they thrive. She said some initially squeamish visitors now seek out carcass feeding, and prominent signs warn off those who might object.
"We have found our community considers it to be a public service we provide," said Houts, noting that carcass feeding also is a good use for roadkill. "It's important for carnivores to do what they are intended to do, and the (carcass) animals are dead anyway."
Carcass feeding, like other forms of enrichment, represents a change of philosophy for zoos, requiring keepers to give up some control so their animals can have more. Some Folsom City Zoo animals refuse to go inside at night while feeding on a carcass. Cats sometimes scuffle over meat, so far without injury.
The National Zoo has taken a few steps in the direction of carcass feeding. Snakes get dead rodents, and birds of prey get dead fish. A small fishing cat catches and eats live goldfish. But fear of criticism and concern about logistics have stopped the zoo from going further.
Would visitors object to seeing Simba gnawing on Bambi at the nation's zoo? The public would have to be prepared, and roadkill would have to be screened for glass or other risks.
"There's a lot of mixed feelings here about it," cat keeper Mindy Babitz said. But "it would be fabulous. (The animals) would love it."
Zoo officials say they know that animals benefit from enrichment because it prevents boredom, which leads some to chew their fur, pace for hours or bang their heads against the bars of cages. Another measure of success is whether animals show skills and behaviors that they would exhibit in the wild.
For primates, the most intelligent animals, keepers provide individualized activities. The zoo's female orangutans like to paint, but the males do not. Two orangutans participate in flashcard quizzes, and although there is a food reward, keeper Rob Shumaker said the mental challenge is what motivates them.
"They are anxious to come to work every day, close to mealtime or not," he said.
National Zoo officials say that they would like to provide enrichment for all creatures but that it takes more work and time than traditional care.
For zoo visitors, enrichment efforts mean that animals are active more often, whether they are playing, foraging or exploring.
Among the zoo's most ardent enrichment advocates is Bob King, assistant curator for small mammals, whose specialty is inventive food delivery systems for the marmosets and shrews and other creatures.
He puts insects in hollowed-out coconuts, drizzles gum arabic on logs and hangs a cloth mop with mealworms in it. Some animals hunt for hidden goodies before eating food that is in plain sight. King thinks his animals are happier.
"You never can know exactly that," he said. "We look at behaviors — species-specific appropriate behaviors. If you have a foraging animal digging for food, that is successful."