Individual versus pseudo-repeatability in behaviour: lessons from translocation experiments in a wild insect

1. Repeatability represents a key parameter in ecological and evolutionary research. Repeatability is underpinned by developmental plasticity and genetic variation but may become biased upwards by repeatable differences in environments to which individuals respond plastically. The extent of upward bias caused by the latter mechanism (causing “pseudo-repeatability”) is important yet rarely investigated in ecological research. 2. We repeatedly assayed a key behaviour (flight initiation distance) affecting longevity in a wild cricket population (Gryllus campestris). We used naturally moving, translocated, and forced-stationary individuals to study bias in repeatability caused by spatial variability in environmental conditions. 3. Our experiments acknowledged that translocations might themselves bias repeatability estimates if animals respond to handling procedures (a necessary component of translocations). Individuals were therefore either (i) repeatedly translocated and assayed, or (ii) a...