Data from: Consequences of multiple simultaneous opportunities to exploit others’ efforts on free riding

Individuals within a group do not all act in the same way: typically the
investors (or producers) put efforts into producing resources while the
free riders (or scroungers) benefit from these resources without
contributing. In behavioural ecology, the prevalence of free riders can be
predicted by a well-known game-theoretical model -the Producer-Scrounger
(PS) model- where group members have the options to either search for
resources (producers) or exploit the efforts of others (scroungers). The
PS model has received some empirical support, but its predictions,
surprisingly, are based on the strict assumption that only one resource
can be exploited at a time. Yet, multiple simultaneous opportunities to
exploit others’ efforts should frequently occur in nature. Here, we
combine analytic and simulation approaches to explore the effect of
multiple simultaneous scrounging opportunities on tactic use. Our analyses
demonstrate that scrounging rates should increase with the number of
simultaneous opportunities. As such, the amount and spatial distribution
(i.e. clumped versus dispersed) of resources as well as the risk of
predation are key predictors of scrounging behaviour. Because scroungers
contribute to reducing the speed of resource exploitation, the model
proposed here has direct relevance to the exploitation and sustainability
of renewable resources.