Data from: Stable producer–scrounger dynamics in wild birds: sociability and learning speed covary with scrounging behaviour

There has been extensive game-theoretic modelling of conditions leading to
equilibria of producer–scrounger dichotomies in groups. However there is a
surprising paucity of experimental evidence in wild populations. Here, we
examine producer–scrounger games in five subpopulations of birds feeding
at a socially learnt foraging task. Over four weeks, a bimodal
distribution of producers and scroungers emerged in all areas, with
pronounced and consistent individual tactic specialization persisting over
3 years. Tactics were unrelated to exploratory personality, but correlated
with latency to contact and learn the foraging task, with the late
arrivers and slower learners more likely to adopt the scrounging role.
Additionally, the social environment was also important: at the broad
scale, larger subpopulations with a higher social density contained
proportionally more scroungers, while within subpopulations scroungers
tended to be central in the social network and be observed in larger
foraging flocks. This study thus provides a rare example of a stable,
dimorphic distribution of producer–scrounger tactics in a wild population.
It further gives support across multiple scales for a major prediction of
social foraging theory; that the frequency of scroungers increases with
group size.