Two male western lowland gorillas, 26-year-old Jontu from the Saint Louis Zoo in St. Louis in Saint Louis, Mo., and seven-year-old Zachary from the Brookfield Zoo in Brookfield, Ill., swapped hometowns in the name of conservation and survival of this critically endangered species.
Jontu
Jontu’s move from St. Louis to Chicago was based on a breeding recommendation by the Association of Zoos and Aquariums Western Lowland Gorilla Species Survival Plan®, a conservation breeding program that manages a genetically healthy population of this species in North American zoos. The recommendation took into consideration Jontu’s personality and genetics.
This move was made with plans to strengthen the western lowland gorilla population by allowing Jontu to lead a family group. He will be joining a group with females to provide stability for the family at Brookfield Zoo.
“Jontu is well known at the Saint Louis Zoo for his regal appearance and confidence as a leader in the bachelor group,” said Helen Boostrom, the zoological manager of primates at the Saint Louis Zoo. “Despite his stature and serious demeanor, he has a very playful and gentle side. The primate care team is going to miss him greatly but is very excited for this new chapter in his life.”
Zachary and the Gorilla Bachelor Group
Zachary was born at Brookfield Zoo in 2015, where he lived with his family at Tropic World. He will join the Saint Louis Zoo’s bachelor group of gorillas, Joe, 25, and Bakari, 18, at Jungle of the Apes. This move also was a recommendation by the Western Lowland Gorilla SSP.
Gorilla bachelor groups are a common type of social group that consists of adult males, also known as silverbacks, and young adult males that live and travel together until they can become part of a breeding group.
The Saint Louis Zoo has a long history with the AZA Western Lowland Gorilla SSP. The Jungle of the Apes team pioneered forming the first bachelor group of western lowland gorillas in managed care and the first successful integration of two bachelor groups.

Gorillas and Conservation
Although western lowland gorillas are the most common of four subspecies of gorilla, they are critically endangered and face the threat of complete extinction in the wild. The Saint Louis Zoo supports western lowland gorillas through the SSP and the Saint Louis Zoo WildCare Institute Center for the Conservation of Congo Apes.
Top Photo Credit: JoEllen Toler © Saint Louis Zoo
Bottom Photo Credit: Jim Schulz © Chicago Zoological Society - Brookfield Zoo
Edited by Sarah Gilsoul, a writer and communications program assistant at AZA.
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