During his last year at the Memphis Zoo, Koga lived alone. The move came after a recommendation from the Association of Zoos and Aquariums Species Survival Plan, which encourages interaction for the naturally social animals.
At the Buffalo Zoo, Koga joins four females. He was introduced to two of them on Thursday.
From an article in the Buffalo News: "Koga laid passively on his back, sat up on his haunches or calmly chewed escarole and carrots as the curious Sidney and Lily gently patted and poked him.
'Theyre testing him to see if hes a good guy or not,' said Cyndi Griffin, head primate keeper at the Buffalo Zoo.
"After living without females for years, Koga, too, seemed mystified rather than annoyed or afraid.
'Hes really laid back; hes not upset by anything,' Griffin observed. 'Hes doing exactly what a silverback is supposed to do.'"
Koga was the Memphis Zoo's last gorilla. Two gorilla brothers may replace him in the fall.