Mechanisms of Behavioural Change in Urban Animals: The Role of Microevolution and Phenotypic Plasticity

Abstract

A key question in evolutionary behavioural ecology is how species cope with changes in their environments. In the last centuries, humans have caused dramatic changes in our planet that have affected the way many animals behave. In order to live in cities, most animals are forced to adjust their behaviour and life histories to the new urban habitat. While growing evidence reports behavioural differences between rural and urban conspecifics as common and cross-taxonomical, the mechanisms underlying such differences in behaviour remain largely unknown. Recent research using animals with limited experience of their natural urban or rural environments points to the existence of intrinsic differences in behaviour between rural and urban conspecifics. This suggests that phenotypic plasticity might not be the only mechanism explaining behavioural differences between rural and urban individuals and that differences in individually consistent behavioural traits could also be the result of microevolution in the urban environment.

Knowing that urbanization is and will continue to be a major environmental challenge to most living organisms, it is urgent to understand the mechanisms allowing animals to cope with our urbanizing world. In this chapter, I focus on the existence of different behavioural phenotypes between rural and urban animals and on the possible mechanisms leading to such behavioural differences.