Taboga, Costa Rica - November 28, 2024 A video from the Capuchinos de Taboga Research Project shows a field researcher delicately collecting urine samples from wild capuchin monkeys using a basket attached to a stick. This meticulous "clean catch" method is crucial for avoiding contamination and provides the foundation for groundbreaking research on how climate change affects wildlife. The study, led by University of Michigan doctoral student Jordan Lucore and published in Science Advances, reveals that higher temperatures significantly weaken the immune performance of these monkeys, with younger individuals being the most affected. When temperatures reach 86°F for about two weeks, the monkeys’ generalized immune systems—the first line of defense against threats—begin to falter. The research is part of the Capuchinos de Taboga Research Project, which has studied the cognition, endocrinology, and behavior of Costa Rica’s white-faced capuchins since 2017. Lucore and the team analyzed a biomarker called neopterin, measurable in urine, to assess immune performance. The younger monkeys were found to be especially vulnerable, as their adaptive immune systems are not yet fully developed. The findings challenge assumptions about endothermic animals like mammals, which are expected to regulate body temperature effectively. “Eighty-six degrees Fahrenheit is not that hot,” Lucore said, emphasizing the study's alarming implications for understanding climate change’s effects. The study involved contributions from U-M professors Jacinta Beehner and Thore Bergman, Emory University professor Marcela Benítez, and a dedicated field team. Long-term impacts of this immune decline on health and reproduction are still unknown, but the research provides critical insight into how rising temperatures could disrupt the survival of even resilient species like capuchins. “Climate change is happening, and it’s going to affect fundamental systems we need to survive,” Lucore said. The video offers a rare glimpse into the precision required for such research, underscoring the urgency of understanding and mitigating these changes.