Seven chimpanzees use ingenuity to escape their enclosure at the Kansas City Zoo

It wasn’t careless zookeepers that were responsible for the escape of seven chimpanzees from their Kansas City Zoo enclosure on Thursday afternoon.

It was clever chimpanzees.

That was zoo director Randy Wisthoff’s explanation for the unauthorized excursion that prompted a “Code Red” response among zoo employees, an hourlong lockdown of zoo visitors and finally a careful roundup.

“Chimps are so smart,” Wisthoff said.

One of them, he said, either found or broke off a 5- or 6-foot log or branch, leaned it against a wall and clambered to the top. Then that chimpanzee — the “ringleader,” Wisthoff called him — persuaded six friends to join him.

At one point, three of the seven chimps went over the wall into an area accessible only to zoo employees. Well before then, however, the zoo had activated its emergency protocols, which included gathering visitors into locked and secure areas.

At no time was the public in danger, Wisthoff said.

The breakout happened about 3:30 p.m., and it took about an hour for zookeepers to herd the animals, in groups of two or three, back into their enclosure.

The chimps were lured with fruit and greens such as carrots, celery and lettuce, their usual feed.

“It was almost their dinnertime already,” Wisthoff said.

But for the last reluctant animal, zookeepers brought out a bag of malted milk balls.

“That was the clincher,” Wisthoff said.

All employees were aware of the dangers the chimpanzees could have posed, Wisthoff said. Of the seven, the largest weighed about 150 pounds.

“They are tremendously strong,” he said.

On Friday, the 100-acre area normally occupied by 12 chimpanzees will be closed as employees check for security breaches.

Employees are careful to police the area and remove large branches, Wisthoff said. That made him wonder whether the log used Thursday had been broken off recently.

About 1,800 people visited the zoo Thursday. Those that remained stayed put during the lockdown.

“We spent an hour in the birdcage,” said the Rev. Celeste Ward, pastor of Emmanuel Repentance Temple of Kansas City, who visited with family members. Zoo employees were respectful in explaining the emergency, she said, and gave them several free zoo passes.

Over in the penguin exhibit, visitor Mari Cintron easily kept three children entertained for the hour they were secured there.

“We just visited with the penguins,” she said. “It was very calm.”

But while some visitors spent the hour enjoying animals, Brie Huffman of Raymore was detained with two friends and many others in a food storage area. Although she grew weary of the heavy smell of animal feed, she appreciated the eight free zoo passes given to her.

“They are good until Dec. 31,” said Huffman. “I will be using all of them.”