Despite this counter-evidence, some polyspecific associations do form under three circumstances. Less conspecific competition, increased group size, and access to different resources helps explain increased foraging efficiency in mixed-species groups. Territory defence also improves with increased group size and less conspecific competition. Thirdly many polyspecific associations form when at risk from predation, because early warning and safety in numbers adds incentive to group with another species. Therefore, although not every species forms polyspecific associations, more research is emerging that these mutualistic behaviours are more adaptive than original theories such as kin selection and selfish behaviour suggest.…
