Effects of an Extreme Weather Event on Primate Populations.

OBJECTIVES: With contemporary, human-induced climate change at a crisis point, extreme weather events (e.g., cyclones, heatwaves, floods) are becoming more frequent, intense, and difficult to predict. These events can wreak rapid and significant changes on ecosystems; thus, it is imperative to understand how wildlife communities respond to these disruptions. Primates are perceived as being a largely adaptable order, but we often lack the quantitative data to rigorously assess how they are impacted by extreme environmental change. Leveraging detections from a long-term camera trap survey, this opportunistic study reports the effects of an extreme weather event on a little-studied population of free-ranging primates in Gorongosa National Park, Mozambique.

MATERIALS AND METHODS: We examined shifts in gray-footed chacma baboon (Papio ursinus griseipes) and vervet monkey (Chlorocebus pygerythrus) spatial distribution and relative abundance following Cyclone Idai-a category four tropical cyclone that struck Mozambique in March 2019.

RESULTS: Baboon spatial distributions were impacted in the first month after the cyclone, with more detections in areas where flooding was less severe. Spatial distributions renormalized once floodwaters began to recede. We describe vervet monkey spatial distribution trends, though sample size limitations inhibited statistical analysis. Primate relative abundance did not appear to substantially decrease following the cyclone, suggesting troops were able to adopt behavioral adjustments to evade rising floodwaters.

DISCUSSION: These findings highlight the behavioral flexibility of Gorongosa's primates and their ability to adapt to extreme-if temporary-disruptions, with implications for primate conservation in the Anthropocene and research into how rapid climatic events may have shaped primate evolution.