Central Washington University researcher Mary Lee Jensvold, Ph.D. studies methods of promoting positive relationships between captive chimpanzees and their caregivers.
The relationships between captive non-human primates and their caregivers are critical to animal welfare. Research shows friendly relationships can improve quality of life; adversely, agonistic relationships can decrease quality of life. Meanwhile, there is evidence of the negative effects of the presence of caregivers and their activities. While caregivers in and of themselves should not be stressful to their charges, their behaviors and the nature of their interactions are likely the basis for stress. One method to mitigate the potential negative effects and to promote positive relationships is for caregivers to employ species-specific behaviors in their interactions with their charges.
With funding from an Animal Welfare Institute Refinement Award, I tested the effect of the use of these behaviors with chimpanzees at The ZOO Northwest Florida in Gulf Breeze. The facility houses three chimpanzees: Zachary, Mr. Zoo Good and Patrick. Prior to collecting data, I trained their caregivers on the meaning of chimpanzee behaviors and how to understand them.
During Chimpanzee Behavior Condition (CBC) data collection, a caregiver used chimpanzee behaviors and vocalizations while interacting with the animals. In Human Behavior Condition (HBC) data collection sessions, a caregiver presented human behaviors and used speech instead. These interactions were natural and usual; caregivers followed the lead of the chimpanzee or the normal routine. This included grooming, playing, serving meals, presenting enrichment or simply observing the chimpanzees as part of the daily check. The chimpanzees were never forced to participate. The caregiver could end the session at any time, but was encouraged to stay for at least 10 minutes.
From videotapes of data collection interactions, data coders recorded the behavioral contexts for each chimpanzee as they occurred. Since the HBC had 78 minutes more data than the CBC, I created a sample of only the first 5 minutes of each data collection interaction, for an equal comparison. The sample showed significant differences in the chimpanzees' response to the conditions. The chimpanzees engaged in more play and grooming in CBC than in HBC, in which they were lessinteractive.
In human interactions, partners often mirror each other's behaviors. If one partner crosses his legs or scratches his head, the other may do so as well. Studies show that when the partners match each other's behavior, the interaction is perceived by outside observers as more positive. Individuals report that when a partner matches his or her behavior, he or she likes that person more. Use of mirroring behaviors can have tremendous impact in client-therapist and student-teacher relationships. Likewise, the results of the current study can have a tremendous impact on the relationships between caregivers and chimpanzees.
The chimpanzee behavioral training included many play behaviors, including play faces and chimpanzee laughter, as well as grooming and submissive behaviors. These are all used by caregivers at my home institution, the Chimpanzee & Human Communication Institute. We have found that the submissive behaviors reduce inter-group aggression. Thus, the use of species-specific behaviors can also improve relationships within the captive group. These findings strongly suggest that caregivers should change their style of interaction to enable appropriate, friendly responses and positive relationships.