Optimal hunting conditions drive circalunar behavior of a diurnal carnivore
Broekhuis F., Grünewälder S., McNutt JW., Macdonald DW.
© 2014 © The Author 2014. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved. Foraging requirements and predation risk shape activity patterns and temporal behavior patterns widely across taxa. Although this has been extensively studied in small mammals, the influence of predation and prey acquisition on the activity and behavior of large carnivores has received little attention. The diurnal activity described as typical for cheetahs (Acinonyx jubatus) has been explained in terms of their avoidance of antagonistic interactions with other larger predators. However, a recent study revealed that cheetahs are frequently active at night, especially during periods of full moon. Being both predator and "prey" in an environment with comparatively high densities of larger and competitively dominant nocturnal predator species, we investigated whether cheetah nocturnal behavior could be explained by favorable conditions for 1) predator avoidance or 2) prey acquisition. We used a data set of continuously recorded behavior created using machine-learning techniques on behavioral data collected in the field to transform recorded 2D activity values from radio-collars into 3 distinct behavioral states (feeding, moving, and resting). We found that 32.5% of cheetah feeding behavior occurred at night and that, in the dry season, nocturnal feeding behavior was positively correlated with moonlight intensity. Our results suggest that nocturnal and circalunar behavior of cheetahs is driven by optimal hunting conditions, outweighing the risks of encountering other predators. Using novel methodology, the results provide new insights into the temporal distribution of behavior, contributing to our understanding of the importance of moonlight and season on the behavior patterns of diurnal species.