Gorillas can be one of the most entertaining organisms in any place they occupy. Ranging from their sluggish posture, to criss-crossing their legs, sticking their tongues out and climbing on one another, they cause one to smile. However, they are widely known for being housed in zoos across the globe where “over 700 million people visit zoos and aquariums each year” . Zoos are a staple activity for children and families. However, the COVID-19 pandemic in 2020 greatly impacted this variable and suddenly, there were no visitors allowed in the zoos. With this great change to the atmosphere, scientists pondered the impact of the absence of visitors on the behaviors of animals in zoos. Mary Masman, Clarice Scarpace, Angelina Liriano, and Susan W. Margulis were curious about this and explored the relationship between gorilla behavior and visitors by conducting an observational study.
At first, they hypothesized, based on previous studies, that there will be no great difference in behavioral patterns with the absence of visitors. Uniquely, they had twelve years of behavioral observation completed before the pandemic which allowed them to carry out this study. The data that was used pre-pandemic was from 2019. This experiment was done at the Buffalo Zoo in Buffalo, New York in an indoor gorilla exhibit. It included two alcoves that hid the gorillas. Next, there were four viewing windows that surrounded the exhibit which allowed visitors to see them. There were five gorillas being observed in the study; one adult male, two adult females, one sub adult female, and one juvenile male. These gorillas were observed and each observer took turns to observe one gorilla at a time (20-minute periods). Each of the gorilla’s activities were recorded at one minute intervals based off of eight behaviors: inactive, locomotion (moving across the ground, climbing), auto-groom (scratching, itching, rubbing, or other self-enforced cleaning), regurgitation and reingestion, pluck (pulling their own hair out), forage (actively searching or eating substrate or other food), out of view (the gorilla itself was beyond the view of the observer), and manipulate object (grabbing, moving, or touching an object). Observations were taken three to five times a week.
The researchers found that there was no significant difference when comparing the group frequency behaviors but there were patterns that occurred. Regurgitation and reingestion were almost twice as frequent in 2019 than in 2020. It was also noted that gorillas were out of view from the public when visitors were absent; 28.16% were out of view in 2020 compared to 18.18% in 2019. Also, manipulation of objects was higher when visitors were present. However, there were significant changes in behavior in individuals. One adult female spent significantly more time out of view, auto-groomed, manipulated objects and regurgitated and reingestion significantly more when visitors were present. Even though not by a significant amount, both sub adult gorillas manipulated objects more often with visitors present and one auto-groomed more than when visitors were present. The adult male auto-groomed more in the presence of visitors and was out of view more when visitors were present. He also engaged more in plucking when visitors were present.
Even though these results showed significant changes amongst individuals, it did not change the behavior of the entire troop of gorillas during the COVID-19 pandemic. These results suggest that visitors have no significant impact on this troop of gorillas. However, while these differences were not significant, the absence of visitors may cause boredom for the younger gorillas because visitors seem more excited when they are in active play. For some gorillas, specifically the adult male gorilla, they demonstrated the opposite. Overall, four out of five gorillas spent more time out of view during the pandemic (no visitors). In addition, four gorillas manipulated objects in the presence of visitors. For example, throwing a blanket over their head while running back and forth. Gorillas enjoy interacting with people, especially younger ones. They are curious about the world around them and enjoy entertainment, which in this case are humans, especially if they exert a reaction from them like clapping and smiling. This means there is a positive correlation between gorillas and human-interaction.
Masman, Mary, Clarice Scarpace, Angelina Liriano, and Susan W. Margulis. 2022. “Does the Absence of Zoo Visitors during the COVID-19 Pandemic Impact Gorilla Behavior?” Journal of Zoological and Botanical Gardens 3, no. 3: 349-356. https://doi.org/10.3390/jzbg3030027
