COS 3-1 - Risk-assessments in the foraging behavior of Artibeus jamaicensis

Animals must forage to survive to adulthood and reproduce, however foraging might expose prey to predators. To avoid consumption, animals adopt antipredator behavior, such as shifting the habitats they forage within, or prey may also shift their foraging time based on predator vigilance. Many nocturnal mammals adjust their foraging habits based on visibility of moonlight and this may be caused by evading visually oriented predators; this avoidance behavior is known as “lunar phobia”. Lunar phobia has been broadly supported in tropical frugivorous and nectivorous bats, and one study at the Barro Colorado Island (BCI) radiotracked Artibeus jamaicensis, Jamaican fruit-eating bats, and found a correlation between decreased foraging time with the waxing moon. In Gamboa, Panama, we tested for shifts in foraging behavior using the time at which A. jamaicensis landed on a platform with banana as a proxy for risk-aversive or risk-prone behavior. We exposed bats to: simulated light (white and half-moon light, full-moon), auditory (owl call + ringtone), and visual cues (owl model + box). When we included all trials where bats flew to the platform before 20 minutes in our generalized linear mixed model, we found that bats approached the food platform slower in simulated full-moon light. When we excluded bats that did not fly before 20 minutes, we still observed a latency to approach the platform in simulated full-moon light, however, bats were also observed to fly faster in ringtone trials. These results differ from previous work and we hypothesize that satiated bats, like those in this study, fly slower to food sources than unsatiated bats. Our work provides a standardized methodology for testing antipredator behavior and decision making in frugivorous bats. By determining how bats behave under various foraging conditions, we may begin to tease a part the relationship they share with their predators and their environment.