Understanding variation in behavioural responses to human-induced rapid environmental change: a conceptual overview

A key issue in animal behaviour is the need to understand variation in behavioural responses to human-induced rapid environmental change (HIREC) such as habitat loss, exotic species, pollution, human harvesting and climate change. Why do some individuals show maladaptive behaviours, while others show adaptive responses to evolutionarily novel situations? At present, we lack a unified conceptual framework for generating predictions and guiding empirical and theoretical work on this critical question. Drawing from the concept of ecological traps, I suggest that a conceptual framework for explaining this variation should include four main points: (1) behavioural responses (adaptive or not) are the result of cue–response systems, or behavioural ‘rules of thumb’; (2) limited or imprecise, unreliable information often underlies suboptimal behaviour; (3) the organism’s behavioural flexibility affects its response to novel situations; and (4) evolution (and development) in past environments has shaped cue–response systems, responses to imperfect information and degree of behavioural flexibility to be adaptive in past environments, but not necessarily in novel environments. The degree of match/mismatch between past environments and novel environments altered by HIREC is thus a key to explaining adaptive versus maladaptive behaviours. I suggest several existing frameworks that address these four points, and are thus potentially useful for explaining behavioural responses to HIREC: signal detection theory, adaptive plasticity theory, extended reaction norms and cost–benefit theory on variation in learning. I further discuss more complex aspects of reality that would be useful to add to these existing frameworks.

► Animals vary in how well they respond behaviourally to human-induced rapid environmental change (HIREC).
► Behavioural responses to HIREC reflect cue–response systems in an uncertain environment.
► Adaptive vs maladaptive responses depend on the match vs mismatch of past environments to novel ones altered by HIREC.
► I review several existing theoretical frameworks that can be adapted to generate predictions on responses to HIREC.