Chimp attack victim stable after 6-hour surgery

>> student from texas is showing signs of improvement after he was mauled by chimpanzees at a wildlife sanctuary in south africa . this morning we're learning more about what may have led to the brutal attack. here is the latest. good morning.

>> reporter: good morning. andrew 's parents are due here at the hospital any morning now. they have traveled right around the world to be at his bedside to comfort him as he comes around from the long procedure to save his life. andrew oberle recovering well after six hours of surgery yesterday. he's stable and being sedated by a team of doctors.

>> i think under the circumstances of having multiple injuries like that, he is doing well. we really are hoping for a positive outcome.

>> reporter: this is the chimp sanctuary still closed to visitors this morning. we were allowed inside to see some of the 33 animals here. each one rescued from poachers, all from a life of an entertainment act. a life that left some psychologically damaged and dangerously volatile. oberle was here on a study trip, an anthropology from the university of texas with a passion for chimps. just before the attack he was giving a presentation about their behavior to a group of tourists. then he was said to cross a fence into a no-go zone. eyewitness accounts said he stepped on a rock jammed into a fence to try to prevent one of the animals from passing by. that may have enraged some of the chimps nearby.

>> i've seen chimpanzees in a lot of different kinds of conditions. i've never seen chimpanzees angry in all my life.

>> reporter: he helps manage the sanctuary. he was on the scene moments after the attack when the chimpanzees moved on him.

>> when they turned on me, there was no other method of confrontation. it was a territorial dispute and i was another threat moving in.

>> reporter: with oberle on the ground, eugene used his knowledge of their behavior to try to calm them down but it didn't work.

>> i climbed out of the vehicle, charged them, fired warning rounds in order to get them to disperse. that usually would do the trick. but in this event, it did not work.

>> reporter: eventually they became restrained. but andrew oberle was by then seriously injured and on his way to hospital. and every member of the sanctuary involved will now be interviewed but also offered trauma counseling to help them come to terms with what they saw. interestingly enough none of them involved said what they witnessed will prevent them from working with chimpanzees in the future, natalie.

>> a lot of prayers for his recovery, here. thank you