Green Monkeys and Ancient Instincts: Undergraduate Students Support Research that Unlocks Behavioral Mysteries

Oct. 2, 2024

By Stephanie Godward, Communications and Marketing Director, College of Arts & Sciences

Isabella Bastien’s fascination with animal behavior inspired her to spend the summer researching green monkeys in Saint Martin, where she hiked trails on the island while examining their anti-predator behavior — despite the fact that they have not been exposed to native predators for nearly 200 years.

“The monkeys are invasive to the island, and their native population is in West Africa,” Bastien said. “In West Africa, they exhibit a lot of anti-predator behavior; if a leopard comes on the ground, they make a certain call, and then everyone runs up into the tree, and vice versa if an eagle is in the sky. There were some research studies that showed that the monkeys in Barbados were afraid of images of the predators from West Africa, and they have been there for a long time — far too long to still remember what their native predators look like.”

Bastien, a junior individualized major in animal behavior, wanted to research if the green monkeys in Saint Martin somehow remembered and reacted to the actual calls of the native predators from West Africa. She conducted this research alongside Hunter Huffman, a junior biology major on the ecology track who is minoring in creative writing. They were both mentored by Rose Amrhein, biology PhD candidate and Graduate Teaching Assistant.

Bastien’s undergraduate research was funded by both the Mentored Undergraduate Research and Creative Activities Grant (MURC) and Summer Research Opportunity Program grant for undergraduate students. The application process for MURC is now open and students can apply before the Oct. 15 deadline.

“Undergraduate research helps introduce students to what it's really like working in a lab. Regardless of what type of work they start doing, they build skills of adaptability, perseverance, and precision that they can carry with them to any future science career,” Amrhein said. “International field research like ours provides greater insight into the challenges and joys of fieldwork. Students learn ways to communicate and collaborate with local people and study animals in their natural environment, while dealing with an array of environmental challenges. I find these experiences are particularly helpful to undergraduates in building their confidence as researchers and choosing their future paths."

The team conducted trials in Saint Martin on eagle calls and leopard calls, and tested them against controls. They hiked to areas where the green monkeys are known to be, patiently observing them until they were in sight. Once they spotted the monkeys, the team set up speakers discreetly to play different sounds: control noises, as well as leopard and eagle calls. Using advanced recording equipment, they monitored the monkeys' behaviors and vocal responses to each sound. They aimed to observe whether the monkeys reacted to predator calls by either moving to safety or making alarm calls to warn each other. The research focused on both their actions and vocalizations in response to potential threats.

“We found that the monkeys were still afraid of the eagle calls, and we were surprised by that,” Bastien said. “Somehow, they still recognized that it was an eagle call, and they still responded correctly to it, which is just so interesting. They are still for some reason afraid of eagle calls and have somehow retained the anti-predator behaviors throughout all of the generations, which is so strange because the monkeys usually learn through observational learning. So somehow, they are still using the call or making sure to teach others the call for some reason, even though there are no eagles there on the island.” 

Through this process of inquiry, Bastien is left with more questions following her findings. Future studies could further investigate the underlying mechanisms of this retention, exploring the role of genetic inheritance versus learned behavior in maintaining these crucial survival responses.

“I think it would be interesting to see if maybe there is some underlying genetic factor to the green monkeys retaining these fears,” she states. “I know that in humans, trauma can affect your DNA, and it can be generational. And I thought maybe this kind of fear of these predators could be applied to humans.”

Bastien initially pursued a biology major on the ecology track but realized through lab experiences that animal behavior was her true passion. She found that some of her initial courses weren’t directly aligned with this interest, so she chose an individualized major to focus more specifically on animal behavior. Her major is a combination of a minor in biology, a minor in conservation biology, a certificate in applied geospatial technologies, and a concentration in animal behavior. This decision allowed her to take a broader range of animal behavior and ecology courses than she would have been able to access otherwise. Growing up in the small town of Glasgow, KY, and later living in Brazil, she sought the resources of a larger city like Louisville, though the size of the campus still offers a comfortable, smaller feel.

Bastien has specifically enjoyed experiencing the community that forms around a research experience.

“It’s wonderful, and that’s not exclusive to our lab – that is just how the Biology Department is here,” Bastien said. "We have a really supportive environment, and we are like a family. Everybody builds each other up, and I know that I can ask Rose and Dr. Perri Eason anything – any question I have – which is amazing support to have. I love doing research and want to get my hands into everything.”

Huffman said that this experience helped him to grow personally and professionally.

“This was a great experience as it provided me with more familiarity with field work, which is an incredibly important skill in ecology,” Huffman said. “It also allowed me to see first-hand the hiccups and problem solving that come with the scientific process. I would definitely say that this experience helped me grow as a researcher and field ecologist.”

Looking ahead, Bastien plans to continue doing research as an undergraduate student, and her ultimate career goal is to conduct animal behavior research in a university setting. Her favorite part of research is discovering something new that perhaps no one else knows yet.

“I just love that feeling of—I did that, we found that out, and now we can tell other people about it. It is just really satisfying,” she states.