Two critically endangered primates leaving Audubon Zoo

The gorillas, a male Western Lowland Silverback Gorilla named Casey, and a male Sumatran Orangutan named Berani, are both headed to different zoos, according to a video posted by the Audubon Nature Institute.

Casey will head to the Louisville Zoo, while Berani is destined for the Denver Zoo.

The moves are part of a strategic Species Survival Plan that is designed to ensure the breeding population of certain endangered species stays at a manageable level and to ensure genetic diversity.

Courtney Eparvier, Curator of Primates for the Audubon Zoo, said extinction is imminent for both species that the pair of primates represent.

The main threat is habitat loss, Eparvier said.

Casey will leave for Louisville on June 12, while Berani will head to Denver on June 23.

"We spend a lot of time building relationships with these guys," Eparvier said. "We hang out with them every day. So saying goodbye to both Berani and Casey is going to be very emotional for us as well because we care about these animals so much. But we know that they are going to be so happy at their new facility and well taken care of."