Dallas A cheetah could do it. So could a chimpanzee. But no one expected a stocky, knuckle-dragging 340-pound gorilla to leap across a 12-foot-wide moat and a wall that separated him from visitors at the Dallas Zoo.
But zoo investigators say that is exactly what happened the day 13-year-old Jabari escaped and went on a 40-minute rampage in March, snatching up a toddler with his teeth and injuring three other people before being shot to death by officers.
The gorilla's flying leap has astounded primate experts and is leading some to rethink the design of the gorilla exhibits at the nation's zoos.
"All it does is give you pause and you think, 'This may be one championship gorilla here, but I've got to be careful because maybe I've got one, too,"' said Terry L. Maple, former director of Zoo Atlanta for 17 years, who has written about gorilla behavior.
At the Dallas Zoo, animals in the gorilla enclosure are roughly at visitors' eye level. Zoo officials who conducted a three-month investigation announced this week that they believed Jabari got a running start and sailed over the trench, clearing the 14-foot wall and an electrical wire atop it that is supposed to give a mild shock.
Some experts speculate Jabari may have been doing a "display run," a showy charge that younger males perform for females or other audiences. Others say he could have been motivated by fear, anger or desire to breed.
Dallas Zoo officials believe he leaped because they could not find evidence of human error, such as open doors, or any objects that could have aided his escape. But zoo director Rich Buickerood acknowledged, "We still have not had anyone come forward yet to say they actually witnessed the event."
As a result, some experts are a bit skeptical that the gorilla made such a leap.
Whatever happened, Jabari's escape moved the zoo to renovate the exhibit where younger gorillas stay, raising the walls to at least 15 feet, adding "gorilla speed bumps" to break up long, flat stretches, and installing "hot vines," electric wires that resemble plants.
"Everybody who knows anything about gorillas is concerned about this, and everybody should be re-evaluating their safety mechanisms as we speak," Maple said.
Gorillas -- though powerful, quick, agile in the trees and believed by some experts to be as intelligent as chimpanzees -- are heavy-boned and were thought to lack the ability to leap long distances.