Advancing Chimp Welfare: The ChimpCARE Tool

Lincoln Park Zoo has long been an active advocate for animal wellbeing, continually striving to further human knowledge in issues surrounding animal welfare—including primates, of course. Thanks to the HBO series Chimp Crazy as well as the reintroduction of the Captive Primate Safety Act, the animals most closely related to us are in the news right now.

Recently, zoo scientists underwent a comprehensive review of the effects of chimpanzee care on chimpanzee wellbeing in zoos, aquariums, sanctuaries, and research facilities. Their results led them to create a brand-new ChimpCARE Tool that is designed to help organizations adapt their chimpanzee care based on the most up-to-date science.

“This project allowed us to synthesize information from nearly two hundred sources and streamline it into a single online tool people can use to make decisions to improve chimpanzee wellbeing,” says Katie Cronin, Ph.D., of the zoo’s Animal Welfare Science Program.

Determining the State of Chimpanzee Research

Prior to creating the tool, they reviewed all the available information on how different approaches to caring for chimpanzees impacts their wellbeing. This review, published in the journal Applied Animal Behaviour Science in June 2024, included space, diet, enrichment, social life, nesting, and relationships between humans and animals. The goal was to “set the stage for evidence-based decision making regarding future practices,” the study noted. Today, there are around 1,200 chimps living in human care in the U.S.,

To understand how chimps are cared for, the study authors—Laura Angley and Gillian Vale, Ph.D., of the Lester E. Fisher Center for the Study & Conservation of African Apes, and Cronin—analyzed 182 publications about chimpanzee welfare science.

Social Lives: Researchers agree that companionship for chimps with others of their species is one of the most essential ways to promote chimpanzee wellbeing. What’s not yet clear is how to determine the exact size and composition of chimp groups for maximum wellbeing, largely because chimpanzees have different personalities and needs. However, current literature suggests that groups of seven or more chimps is a good goal, especially if the group includes multiple males. Age diversity can offer some benefits, but breeding and the presence of infants haven’t necessarily been shown to increase welfare.

Space: The researchers found that chimpanzees will begin to change their behavior to avoid conflict when space becomes limited, and small spaces can result in less social cohesion. When chimpanzees are provided with more space, and more naturalistic, useable spaces (think climbable walls, for example), and the option to move away from others if they choose, their wellbeing improves.

Diet: Most of the diets for chimpanzees in human care are based on the diets of wild chimps and the nutritional needs of humans—but this may not be sufficient. Chimps may require more fiber than zoo and sanctuary diets currently allow for, but this is an area where much more research is needed. Feeding chimpanzees in a way that encourages them to spend time searching for food as they would in the wild supports good wellbeing. Additionally,feeding more diverse diets, feeding at unpredictable times, and spreading food out to minimize aggression and increase search times can enhance welfare.

Nesting: Nest-building is an important part of chimpanzees’ daily lives. Many people don’t know that these large-bodied animals build new nests every night in the wild, typically up in the trees! The quality of nests can improve sleep in some apes, which in turn increases their brain function. This study notes that providing chimps with a variety of clean, dry nesting materials such as branches and blankets daily, which they can use to createnests at different heights, is a good way of supporting their welfare.

Relationships With Humans: Chimps in human care can encounter strangers (like zoo guests) daily. But they also have people, such as keepers, with whom they may develop social bonds. Chimpanzees differentiate between familiar and unfamiliar people. In modern zoo and sanctuary settings that offer visual and auditory barriers as well as space where chimps can retreat to, chimpanzees can be comfortable in the presence of visitors.  Research does show that positive reinforcement training is an integral part of chimp welfare and management, fostering a strong relationship between humans and apes while potentially improving social behavior and play and decreasing stress-related behaviors.

Conclusions: Angley, Vale, and Cronin point out that one of the issues with their research is that it does a lot of generalizing—and chimps come from many different backgrounds that are not necessarily accounted for when looking at broad patterns in the current science.

“Furthermore, the individual differences in chimpanzee personalities and preferences are well documented, underscoring the emerging need to focus on offering choices to the chimpanzees in our care so they can be partners in tailoring their worlds to support positive welfare,” the study notes.

The ChimpCARE Tool: Taking the Next Step

After Lincoln Park Zoo researchers determined what scientists know and what they still need to discover, they put that knowledge to use.

Before now, there has been no comprehensive, chimpanzee-specific tool designed to help people adapt or plan their care of these animals based on current data. So, Lincoln Park Zoo developed one. Zoo scientists compiled all the papers they’d analyzed to come up with a free web-based resource that evaluates chimp care practices for their effects on chimpanzee welfare. It’s called the ChimpCARE Tool—and it stands for Community, Advocacy, Research, and Education.

The tool can serve several functions. It can allow users to advocate for enhancements to care or habitat design, prioritize actions that may have positive effects on welfare, track progress over time to quantify improvements, and plan for future habitat designs or husbandry actions. It also allows institutions to measure their own preparedness to care for chimps. Data are not stored nor shared, so people can use it privately to determine how to best care for chimpanzees. And the Lincoln Park Zoo team remains available to help users through the process.

“One of the greatest things about the ChimpCARE Tool is that it produces a report for users that indicates areas of strength and opportunities for improvement, and explains the rationale behind why,” Cronin explains.

The ChimpCARE Tool is available for free online. It is also being introduced to other institutions and facilities through Zoom sessions and being shared through the Association of Zoos and Aquariums and the North American Primate Sanctuary Alliance. To access it and find out more information about how it can be used, visit chimpcare.org/tool.

Funding for the development of the ChimpCARE Tool and continued support has been generously provided by The Arcus Foundation.