Anthropogenic change and the loss of behavioural diversity

Behavioural diversity is an important but understudied facet of biodiversity that enables wildlife populations to cope with rapidly changing environments. There are a growing number of studies showing that anthropogenic changes to the environment can reduce behavioural diversity in populations and species, which in turn may reduce their ability to tolerate or escape from new stressors when they arise. To understand the causes and consequences of behavioural diversity loss, we propose a conceptual framework for predicting generally expected patterns of behavioural diversity in a changed and changing world. To do so, we begin by describing the key sources of behavioural diversity: genetic polymorphism and behavioural plasticity. We then discuss how anthropogenic disturbances, such as habitat homogenization, reduced connectivity and the introduction of novel environments and entities, can impact behavioural diversity through the evolutionary forces of selection, flow, mutation and drift. We do so by reviewing the evidence base and highlighting important gaps in knowledge. Understanding the mechanisms of behavioural diversity loss is essential for identifying and mitigating the specific drivers of decline, helping practitioners to conserve this variation and improve the capacity of populations to adapt and persist under future environmental change.