Figure 4. Animal behaviour can redefine ‘multiple stressor’ scenarios: When effects of stressors carry over into periods of time when the stressors are not present, this allows multiple stressors that are not correlated in time and/or space to nonetheless have ‘co-occurring effects’ on mobile organisms. Here, stressor 1 (S1) and stressor 2 (S2) co-occur in time and space (top right), co-occur in space only (top right), co-occur in time only (bottom right), or neither co-occur in time or space (bottom left). In these latter two scenarios, animal movement and space-use decisions can cause ‘multiple stressor effects’ if at least the first stressor experienced has carryover effects. The optimal decision (e.g., be active vs. inactive, move to an area with one stressor or an area with the other) in each of these scenarios depends on costs of avoidance in space or time and the relative strengths of stressor effects.