Around midnight on June 12, a pair of chimpanzee siblings arrived safely at Chattanooga Zoo after traveling from their home at Houston Zoo. Willie, a 22-year-old male, and Sally, a 40-year-old female, would soon be introduced to the four chimpanzees already residing at Chattanooga Zoo: Scott, Shirley, Brandy and Katrina.
“Willie and Sally were specifically selected to join our troop due primarily to their personalities, behaviors and ages,” said Lacey Hickle, director of animal care and conservation at Chattanooga Zoo. “They’ll also help us maintain a slightly larger troop size, which is beneficial for all the chimps’ social needs, and Willie will help ensure we have a male presence in the troop for years to come, which is important for a patriarchal species like chimpanzees who tend to have a leading alpha male in the group.”
Chimpanzees are an extraordinarily intelligent, social and territorial species. In the wild, they are known to attack unfamiliar chimpanzees from other troops, making a strategic and careful introduction process vital to their safety and wellbeing.
“Many months ago, we wrote an introduction plan based on knowing our chimps' personalities to decide who we should introduce first,” said Bri Towers, lead primate keeper at Chattanooga Zoo who previously worked with Willie and Sally as a Houston Zoo keeper. “We sent our plan to the Species Survival Plan (SSP) Chimp Husbandry and Training group for feedback and tips as well.”
Initially, Willie and Sally were housed apart from the other four chimpanzees, and a divider sheet was hung up in their indoor space so the two groups could hear but not see each other. After a week, the divider was removed during supervised visual introductions. Next, Chattanooga Zoo’s animal care team started face-to-face introductions between the current residents and the newcomers.
“We started physical introductions with Scott (a 39-year-old male) and Brandy (a 41-year-old female) because they remained calm and showed signs of interest during visual intros,” said Towers. “However, Brandy was not a fan of Willie at first. She even tried to chase him around a few times.”
For the next day of introductions, Shirley (another 41-year-old female) took Brandy’s place and went with Scott to meet the new chimpanzees face to face. This introduction was more successful, including an immediate hug shared between Sally and Shirley.
In the following days, all six chimpanzees at Chattanooga Zoo spent time together and began to reform their social structure in a process that Towers described as “surprisingly good.”
“Chimpanzees are community-oriented primates, and their complex social dynamics are hierarchical,” said Towers. “It’s really important to let the chimps resolve their altercations and tensions on their own without us intervening, even though there’s potential for injury. Thankfully, in our case, intros consisted of some screaming and attempts at intimidation, but no one really touched each other. They just have to get it out of their systems and determine the social order — that’s just how their social structure works.”
Some of the exact details of their social order are still being observed by animal care staff — such as the continual transition of alpha male status from Scott to Willie — but all chimpanzees are now living together in full contact with minimal issues between individuals. All six chimpanzees can be seen in their habitat in Chattanooga Zoo’s Gombe Forest section.
For a more robust retelling of chimpanzee intros at the Zoo, visit Chattanooga Zoo’s blog at www.chattzoo.org/blog/new-chimps.
To learn more about Chattanooga Zoo and to purchase tickets, visit www.chattzoo.org. Chattanooga Zoo is home to over 150 different species, and tickets start at $11.95 for children, $12.95 for seniors and $14.95 for adults.