Date of Award

May 2016

Degree Type


Degree Name

Master of Science



First Advisor

Trudy Turner

Committee Members

Pat Gray, Fred Anapol


Animal Welfare, Chimpanzee, Enclosure Use


Current research continues to identify the cognitive and social abilities of chimpanzees, as well as the imperative to provide a complex environment in captivity that allows them to practice and use their minds appropriately (Ross 2009). The goal of this research is to investigate how chimpanzee social relationships change based on the available amount of enclosure space in a captive setting. The project’s study group is made up of six captive born chimpanzees housed in a naturalistic enclosure at the Lincoln Park Zoo in Chicago, Illinois. Data is taken daily as a part of a long-term study at the Lester E. Fisher Center for the conservation of great apes. Research has shown that choice is an important aspect of animal welfare. This study looks at the interindividual distance between dyads of chimpanzees and how the distance changes when the enclosure space changes. Multilevel analysis was used to create an expected pattern of distance between four different space conditions using both average distance and relative distance. The expected pattern shows the order of spacing across the different conditions, meaning the relative interindividual distance between two individuals is expected to be the largest when the animals are locked inside and the smallest when the animals are locked outside. It was found that the animals do spread out further when they have a larger amount of space when looking at the average distance between dyads. When looking at the relative distance between dyads, it was found that the animals use a higher percentage of space when there is less available and dyads always follow the expected pattern of interindividual distance. Female dyads were shown to be the closest in this group. Dyad differences do occur across the four conditions and are discussed using known chimpanzee social patterns. Welfare implications and research showing how naturalistic enclosures promote natural behavior in captive settings is addressed.

Ross, S et al. (2009). Space use as an indicator of enclosure appropriateness: A novel measure of captive animal welfare. In Applied Animal Behaviour Science. 121:42-50.