In custody again but chattering only among themselves, the seven chimpanzees that briefly escaped Thursday from their habitat at the Kansas City Zoo are offering no clues as to exactly when they hatched their plan to go over the wall.
Maybe it was spontaneous.
Or it could have been plotted long ago.
When animal escapes happen — and they do — zookeepers know the reasons, which can be human error or the more naturalistic designs of modern zoos.
In the chimp case, Kansas City Zoo director Randy Wisthoff and other experts on Friday acknowledged that the peripatetic primates certainly had the tools they needed:
• Big brains.
• A scalable tree branch.
“My assumption is that the chimps were planning this for a long time,” said Matt Schindler, president of Wichita-based WDM Architects, which in part specializes in zoo exhibit design. “Sometimes when they have nothing but time on their hands, they can do a lot of thinking and figure out ways to get out of things.”
Oh yeah, speaking of those hands, don’t forget:
“They have thumbs,” Wisthoff said. “They have the ability to use — whether you want to give this credit or not — to use and make tools. Because of that, it becomes a constant vigil on our part to prevent that process from taking place.”
Zoo animal escapes happen rarely, about five times a year on average over the last five years, said Rob Vernon, spokesman for the Association of Zoos & Aquariums, which represents and accredits 213 zoos and aquariums in 47 states.
Most often, Vernon said, animals escape because of zoo staff error, typically after a door or enclosure is left often.
In March, the staff at the Spring River Zoo in Roswell, N.M., left the water running into a moat that helped confine a baby bear cub. The moat filled up enough to allow the cub to swim across, scale the exhibit cage and clamber onto its roof. The zoo was evacuated as the New Mexico Department of Game and Fish was called to use food to coax the bear back into its habitat.
“The bear was running around on the roof, on the edges of the roof, all the way back and forth,” zoo director Elaine Mayfield told the local media.
At the Houston Zoo, also in March, a pack of six mongooses escaped outside their holding area in the children’s portion of the zoo.
Zoo spokesman Brian Hill wouldn’t say Friday how the mongooses got out, but he said they never entered the public area and were all back in place by the next day.
“For a couple of the mongooses, keepers were able to coax them into the kennels just by calling them. … ‘Here mongoose, here mongoose.’ Yes, it worked,” he said.
At the Kansas City Zoo two years ago, the staff was forced to wrangle two gorillas back into their enclosures.
“We had a couple of gorillas that got in the back” hallway, Wisthoff said. “They didn’t get out into the zoo. That was keeper error. Two keepers were working together, and one assumed that door had been shut and locked and it hadn’t been.”
Escapes also sometimes occur as a consequence of more naturalistic exhibits designed to better mimic an animal’s natural habitat.
The exhibits are designed with safety being paramount — not only to prevent animals from coming in contact with humans, but also to prevent humans from getting at the animals. Tall walls, deep moats and electrified fences are all used.
But sometimes nature can interfere when tree branches fall over and create bridges or ladders, or when moats fill during rainstorms.
Last June, a red panda escaped from the National Zoo in Washington and was later found wandering down residential sidewalks and in backyards. An investigation showed that the panda probably climbed out of its enclosure using tree branches that were hanging low during a rain.
On Friday at the Kansas City Zoo, Wisthoff said, his staff spent much of the day and would continue working through the weekend if need be to inspect and clear the chimpanzee habitat of any deadfall or tree branches that might be used for another escape attempt. Wisthoff said the keepers inspect every animal enclosure every day for anything that might aid an animal in exiting.
“We do that with every exhibit, whether it is chimp or cheetah or tiger,” he said.
As the staffs at the Denver and Indianapolis zoos know, there is always intelligence.
Last year in Denver, a meek, 17-year-old howler monkey named Rose broke out of her habitat by chewing through her steel mesh enclosure. Shy and skittish, she was not considered a dangerous “Code Red” animal. She was found sitting in a planter outside her exhibit.
In March, a 9-year-old male orangutan, Rocky, and his adoptive mother, Knobi, broke out of their primary enclosure and were found in an inner enclosure in the Indianapolis Zoo’s new $26 million International Orangutan Center, scheduled to open to the public in May.
The animals were never near the public, although 60 visitors were asked to wait inside the zoo’s dolphin exhibit until the animals were collected. Rocky and Knobi are two of the eight orangutans that had been placed in the exhibit in order for them to acclimate to their home and for the zoo to test the enclosure’s vulnerabilities.
Rocky was found after zookeepers discovered he had dismantled the enclosure’s webcam.