Andrew Oberle, the University of Texas-San Antonio graduate anthropology student attacked by chimpanzees in South Africa, was transferred Thursday from a regional hospital in Nelspruit to a larger hospital in Johannesburg.

ABC News reported that his family and doctors opted to move him so he could get better medical care. His parents flew in from the states to be with their son. “His parents are, well, they’re quite traumatized,” said Robyn Baard, a spokeswoman for the Mediclinic hospital in Nelspruit Wednesday. “They have requested privacy.”

Before leaving for South Africa, his father told ABC News that, when he recovers, Oberle will likely go back to doing what he loves: working with chimps. “I’m sure if he’s able to do it, that he is probably going to be right back there when he can,” Andrew Oberle Sr. said. “That is what he wants to be doing.”

Oberle’s roommates— Anthony and Marissa Reimherr and his wife, Marissa—created a Facebook page to collect donations for his medical care and get the word out on his condition. More than $22,000 had been raised as of Thursday.

CNN gave this account of the attack:

Witnesses to the attack said that Oberle went into a no-go area because he seemed to want to remove a stone close to one of the animals that could have been picked up and thrown around, Cussons told CNN.

Oberle crossed one barrier and approached a second one, which is a main fence with 24 strands of electrical wiring, Cussons said. Two male chimps grabbed Oberle and tried to drag him under the fence, but were not able to yank him into their enclosure.

Cussons said he estimates the attack lasted 15 minutes.

At some point, people tried to stop the chimps, and Cussons shot two rounds in the air to see if that might get them to retreat, he said. One of the chimps then charged at Cussons, he said. Cussons shot that chimp in the abdomen, he told CNN, and it seemed to shriek as a kind of signal to other chimps that there was a more powerful threat present. The chimps then backed off, he said.

Oberle was rescued and transported for medical care.

Oberle first volunteered at the chimpanzee sanctuary, the Jane Goodall Institute’s Chimp Eden, in 2010, CNN reported.

According to the San Antonio Express-News, Oberle moved to San Antonio to attend St. Mary’s University. He had hoped to enroll in a doctoral program after completing his master’s degree this coming fall.