Male silverback, Oliver
Posted August 2021
Three Western lowland gorillas, who transferred from the Columbus Zoo and Aquarium in April, have settled into their habitats at the Milwaukee County Zoo and can be seen by visitors.
Male silverback, Oliver, and females, Nadami and Dotty, completed their quarantine time in an off-exhibit area at MCZ (all arrivals to the Zoo spend at least 30 days in quarantine for their health and safety), and visitors can see them in the indoor Apes of Africa habitat. (Although the gorillas have been acclimated to the outdoor habitat also, this observation area is not yet open to visitors due to COVID-19 protocols.)
Oliver, Nadami and Dotty lived well together as a family unit at the Columbus Zoo. Animal Care staff at MCZ say 32-year-old Oliver is a very laid-back gorilla, and he’s content to sit back and observe what’s happening around him. He steps in only when necessary. Even though he is hearing impaired from an illness when he was young, he communicates well with his troop and his keepers.
In communicating and training with Oliver and the other apes, keepers use hand cues paired with verbal cues to ask for behaviors like shoulder presentations, to help the animals participate in their own healthcare. Keepers say Oliver is very intuitive and follows the female gorillas’ cues.
At 17 years old, Dotty started off being very respectful and calm, especially with the keeper staff. Now that she’s more comfortable, her personality is showing, and she often vocalizes with her care staff during feedings if they’re taking too long or if she’s offered a food item she doesn’t prefer!
Nadami, who is 10 years old, is a bit more hesitant around the other gorillas, but very sweet when interacting with keepers. As the youngest of the three gorillas, she spends most of the time moving around the exhibit, often seen making gestures toward Oliver and Dotty in the hope of initiating play behavior.
After the quarantine time was completed, keepers allowed the gorillas to see the new public habitat areas before they were introduced to them, and had access to areas they were already comfortable with, always having the choice of where they wanted to be. Once comfortable in a new space, keepers discontinued access to the additional areas. Overall, everything progressed smoothly. The family group has adjusted to anything new that has been presented to them, and they’re slowly getting more comfortable as a cohesive group.
The Milwaukee County Zoo is also home to two male gorillas, 29-year-old Maji and 26-year-old Hodari. Maji and Hodari are half-brothers, who have the same mother, and have spent most of their lives together. Bachelor groups like Maji and Hodari are necessary in zoo populations to provide the social needs of other non-breeding males. They are managed and cared for as a separate group, and even though they won’t be introduced to Oliver’s troop, from the start Maji and Hodari could hear, smell and see the new gorillas in the quarantine area.
Early on, Maji liked to bang around and generally make his presence known to the family group, while Hodari had a more positive reaction to the new residents. Maji also shows more posturing with the new gorillas which is typical behavior when two silverbacks see one another. Because of this, in the holding area, keepers constructed a visual barrier, so the family group has some down time and doesn’t feel the need to be wary of the display between Maji and the group. It doesn’t seem necessary for Oliver to initiate any displays, but sometimes he reacts to Maji’s displays. On occasion, the females display back at Maji.
Both Nadami and Dotty, who are excellent genetic matches for Oliver, have received Species Survival Plan® (SSP) recommendations to breed with him at the Milwaukee County Zoo as part of the efforts to help protect the future of the species. Future breeding most likely won’t occur for a while (both females are on birth control) so the gorillas have time to fully acclimate to their new home. During this time, keepers continue to work on building strong relationships with the group and work on behaviors that may be necessary for a future pregnancy such as abdominal ultrasounds.
Keepers say it’s been great fun getting to know the new animals, as all gorillas have unique personalities and specific needs. One of the gorilla keepers goes on to say, “It’s great figuring out their personalities and making that connection so we can cater to their individual preferences. “I can’t wait for the public to fall in love with these new gorillas as well!”
For more information, please contact the Zoo’s Marketing and Communications Department at 414.256.5466.
According to the International Union for Conservation of Nature (IUCN), Western lowland gorillas are listed as critically endangered. Habitat loss and deforestation have historically been the primary cause for declining populations of Africa’s great apes. However, experts now agree that the illegal commercial bushmeat trade has surpassed habitat loss as the primary threat to ape populations – particularly for Western lowland gorillas.