1. How does sociality impact vulnerability to climate change?
Sociality shapes bees’ life histories, physiological traits, and behavioral repertoires. These traits can broadly influence how bees respond to climatic variables, and therefore their vulnerability to environmental change (Figure 1). Group living has been proposed to provide buffering effects against environmental variability (Kennedy et al., 2018; Komdeur and Ma, 2021), which may explain why cooperatively breeding animals to thrive in regions characterized by strong climatic variability (Jetz and Rubenstein, 2011; Lukas and Clutton-Brock, 2017; Sheehan et al., 2015). While a considerable body of literature explores effects of climate change on bees that are social, many fewer investigate social effects at the species level, i.e., by assessing social behavior as a predictor variable across bee species. Where data do exist, patterns have been mixed. Some studies have found significant relationships between sociality and climate-relevant functional traits, like desiccation resistance and thermal tolerance (da Silva unpub., Hamblin et al., 2017). Others have shown that sociality was weakly or not at all associated with climate change responses, including phenological shifts (Bartomeus et al., 2011; Meiners et al., 2020) and responses to extreme weather events (Graham et al., 2021). More commonly, studies have evaluated sociality as a predictor of responses to anthropogenic landscape change. Social bees may be less susceptible than solitary bees to urbanization (Banaszak-Cibicka and Żmihorski, 2012; Harrison et al., 2018) and agricultural intensification (Forrest et al., 2015; Hall et al., 2019). While these studies are informative for suggesting general patterns of social resilience to environmental change, more work investigating climate variables specifically is necessary to understand social trait-related responses to climate change. A promising starting-place to generate predictions for these studies is by examining life history, behavioral, and physiological trait variation between social and solitary bees.