HILO — Two infant binturong out of a litter of three at the Panaewa Rainforest Zoo have died of natural causes. A third, which was rejected by the mother, is thriving as zoo staff hand-raise the young bearcat.

The first bearcats born in captivity in Hawaii since the 1980s, the trio was discovered by zoo staff on Feb. 10. The animals are native to Southeast Asia and are endangered in portions of their range.

Veterinarians believe one of the bintlets died from falling as the mother led it climbing inside the cage. The second appears to have succumbed to salmonella.

"When they're out in the open, there's always that risk," said zoo manager Pam Mizuno.

"Keoki," the surviving male, lives in a metal cage in the zoo office. He weighs over four pounds and recently had his first vaccination.

"He's going to move us out soon," Mizuno said. "He's active and climbing all over the place."