Zoo sues for return of the late Koko’s gorilla companion

CINCINNATI — The Cincinnati Zoo is suing for the return of a gorilla loaned to a California conservatory as a companion for Koko, the late gorilla famed for mastering sign language.

In a complaint filed Thursday against The Gorilla Foundation, attorneys for the zoo said Ndume, a 37-year-old silverback gorilla, has lived in isolation to his detriment since Koko’s death in June.

The zoo sent Ndume to the foundation in 1991 under a contract that was revised to say he would be transferred after Koko’s death. In the months that followed, the Gorilla Species Survival Plan recommended Ndume move back to the zoo where he was born.

The complaint alleges that the foundation violated the contract when it refused to coordinate Ndume’s planned return.

Francine Patterson, an animal psychologist who cared for Koko and is co-founder of The Gorilla Foundation, wrote in a September letter addressed to zoo officials that a move would harm Ndume by causing unnecessary stress. She said it would also exacerbate an “ongoing suffering after the loss of Koko.”

In the letter, Patterson said Ndume screamed, banged and shoved objects for 14 consecutive hours after overhearing talk of a transfer — behavior the gorilla had never before exhibited at the foundation. Patterson said gorillas’ ability to understand human speech is underestimated and that the foundation’s “decades of experience communicating with them confirms their ability to do so.”

Ron Evans, curator of primates at the zoo, acknowledged that every transfer has its risks, but Ndume’s isolation presents a greater concern.

An official with People for the Ethical Treatment of Animals said in a statement that Ndume deserves the opportunity to thrive and socialize with other gorillas.

Patterson acknowledged Ndume’s need for a social group but emphasized that he is not technically alone. “He is with a strong family support group of human great apes, from whom he takes great comfort,” she wrote.

A federal judge in San Francisco will decide Ndume’s future.