Modular Fowl: 'Behavioral Syndromes' as an Epiphenomenon

Individuals of many species differ consistently in their behaviour. Such 'personalities' or 'behavioral syndromes' appear to be heritable and are hence conceived as characteristics that are under selection pressure. The hallmark of behavioral syndromes is that they predict responses across a variety of contexts. We studied male fowl under naturalistic conditions and found that individuals in hierarchically-structured social groups appeared to have stable individual differences. We subsequently tested the same males in a lab virtual environment in which they were shown stimuli simulating three functionally orthogonal contexts: raptors (predator), rival males (territorial) and food in the presence of a hen (courtship). Crow rate and movement prior to stimulus presentation were correlated for ll contexts, but these were the only behavioural measures out of 10 used that seemed to reflect a behavioral syndrome . In particular, responses to each stimulus type failed to predict behaviour in other contexts. We conclude that extrinsic factors can be responsible for the appearance of 'personality' traits that could readily be mistaken for the product of endogenous ones.