Chimp Hugs Woman Who Saved Her Life 20 Years Ago

On a January morning in 1974, a group of lab chimps who hadn't seen sunlight for six years were given the opportunity to run from their cold, steel cages onto the grass. But they were too scared to budge.

"They were terrified to get out of the security of their transport cage," Linda Koebner, an animal behaviorist and their caretaker, says in a segment from a 1999 documentary called "The Wisdom of the Wild." "Whether it was afraid to step on the grass, they hadn't been on anything but hard bars for years, or just the feel of the wind and the sun. They just huddled in the doorways and wouldn't come out."

But eventually Koebner, who was a graduate student at the time, eased them onto the grass.

The chimps, who'd been used for hepatitis research, were no longer needed in labs because a vaccine had been found.

And so they would be released onto a preserve in southern Florida, but they would need Koebner to teach them how to be wild.

Koebner, who eventually founded Chimp Haven in Louisiana, spent the next four years with the chimps.

"Chimpanzees have provided us so much in this world," she says in the film. "So much knowledge about ourselves, about our social lives, about our dispositions, because they are so much like us as beings."

But eventually, it was time for Koebner to move on.

Then, two decades later, she returned to say hello to the few who remained.

"It's been so long," she says in the film. "Oh, you look great."

She hadn't had any contact with them at all for the past 18 years, so she kept a respectful distance at first.

Then, as she gets closer, she reaches her arm out. "Do you remember me?" she asks again.

A chimp named Swing, with a huge grin on her face, reaches out her hand to take Koebner's. Within seconds, they're hugging, and then another chimp, named Doll, gets in on the action too.

"These chimpanzees have taught me about resilience," Koebner says. "All of these have gone through such tremendous adversity, and yet they're forgiving, and they're whole again."

Because they share 98.8 percent of our DNA, chimps have long been used as "ideal" models to test drugs and vaccines.

But, in the United States last fall, chimpanzees were listed as an endangered species, bringing experimentation on them to an end. And they are having their day in the sun with a new documentary that illuminates their plight.

Sadly, though, there are still hundreds living in labs, waiting to be officially retired to a sanctuary.

If you'd like to help former lab chimps live a better life, you can donate here or here.

Watch the full video, in which Koebner also says goodbye to a chimp friend for the last time, here: