Individual differences in learning ability are negatively linked to behavioural plasticity in a frequency-dependent game

Abstract

Behavioural plasticity can be costly, but is advantageous when it allows animals to adjust their behaviour to current conditions. Since individual differences in learning ability could be a source of differences in behavioural plasticity, the frequency dependence of payoffs within a foraging group may permit the coexistence of both plastic, fast-learning individuals and nonplastic, slow-learning individuals; in a frequency-dependent context the adjustments of a few benefit all. In this study, we investigated whether individuals that learned faster in a simple associative learning task were also more likely to adjust their behaviour in a social foraging game context than their slower-learning groupmates. We measured the associative learning ability of female Bengalese finches, Lonchura striata domestica, in a colour discrimination task and their degree of behavioural plasticity in tactic use when foraging conditions called for changes in the flock's producer–scrounger equilibrium. We found that behavioural plasticity was affected by learning speed. However, in contrast to our expectation, the slower learners were most plastic. We argue that behavioural plasticity in the producer–scrounger game context may require learning that is different from colour matching. We also propose that our results may be related to the fast–slow continuum; being proactive or fast and inaccurate could favour being responsive in simple asocial contexts while being reactive or slow and accurate could favour being plastic in more complex social contexts. Future empirical studies need to compare differences in behavioural plasticity in tactic use with learning speed measured in other types of learning tasks and with personality traits relevant to the fast–slow continuum.