Ultimate and proximate analyses of behavioral responses

Insects, being ectotherms, are particularly prone to the effects of a warming temperatures. Behavioral responses, which allow animals to rapidly cope with changing environmental conditions, represent some of the most immediately observed effects and best documented responses to climate change. However, such behavioral responses are rarely considered through the lens of Tinbergen’s different levels of inquiry, which remains a bedrock principle in the study of animal behavior. This approach, by carefully distinguishing adaptive, evolutionary, developmental, and mechanistic perspectives, allows an important distinction between proximate (how?) and ultimate (why?) answers to questions about behavior. In this primer, we explain the utility of these different levels of inquiry and how they can enhance our understanding of behavioral responses to climate change.