Integrating climate variability, behavior, and species interactions in a large carnivore guild

Environmental change has contributed to our planet currently undergoing a “6th mass extinction”, in which 40% of vertebrate species have experienced severe population declines. Identifying the mechanisms underlying species responses to environmental change is a pressing challenge and essential to mitigating global biodiversity loss. Global environmental change remains a leading threat to biodiversity, and altered species interactions are a primary driver through which climate variability impacts populations. In particular, changes in predation and intraguild competition (i.e., competition between species that share the same food resources) are among the proximate mechanisms most widely implicated in climate-driven population declines. Animal behavior can strongly mediate how individuals and species respond to environmental variability, and thus should mediate how climate variability impacts interspecific interactions like predation and competition. However, little research has examined the behavioral mechanisms driving climate impacts on species interactions, particularly at top trophic levels. This research will advance our understanding of how animal behavior mediates changes in upper-level trophic interactions by assessing how climate variation affects the behavior and interactions of four African large carnivore species in Botswana. In addition, this work will build local capacity for wildlife research by providing training for African field assistants, as well as providing training for undergraduate, graduate, and postdoctoral researchers. Finally, by partnering with a local environmental education program, we will integrate our research into a new learning module on local wildlife. Because altered patterns of predation and competition are primary mechanisms by which global environmental change leads to population declines, it is critical to understand how and why climate variability modifies species interactions. Animal behavior is likely an underappreciated pathway through which climate changes alter these interactions, providing a key missing link between environmental change and ecological patterns. The goal of this research is to understand the patterns, drivers, and consequences for predation and competition of individual- and species-level variation in the behavioral responses of top predators to climate variability. This work builds upon a unique behavioral dataset from high-resolution GPS and accelerometer data from four African large carnivore species, spanning an 8-year period that included three drought events and the hottest local temperature on record. We will couple behavioral observations and the collection of new collar-derived data to parameterize a machine learning model to classify behaviors (stationary, mobile, hunting, feeding). We will apply our classification model to retroactively identify behaviors in the historical data. We will then integrate these classifications with high-resolution environmental data to assess how climatic variation influences individual behavior and subsequently predation and intraguild competition. In Aim 1, we examine intra- and interspecific variation in behavioral responses to temperature and drought severity within the large predator guild, and evaluate the mediating role of two key predator functional traits – body size and hunting mode. In Aim 2, we examine how variation in climate-driven behavioral responses scales up to affect patterns of predation and intraguild competition. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.