As demonstrated by honey bees, stingless bees, and many ants, collective foraging in large groups can be an extraordinarily effective strategy in certain environments. Communication is a key component of this foraging strategy. Empirical research with honey bees has shown that communicating location information via the waggle dance increases foraging success in some environments, but not others. However, exactly how communication drives foraging success is still unclear. It might (1) reduce individual searching time, making foragers more efficient and/or (2) direct foragers to higher quality resources. To test these hypotheses, we measured individual foraging success of honey bees across three different environments, and compared this to the benefits of communication to entire colonies measured in the same environments. In particular, we examined the success rate and time spent foraging for bees, depending on whether they had previously been successful (employed vs. unemployed) and whether they had previously followed a waggle dance (scout vs. recruit).
Results/Conclusions
First of all, we found that in environments where the benefits of communication were high, foragers had a higher success rate overall. In particular, dance recruits were significantly more likely to be more successful than scouts in those environments. This was not simply driven by an improvement in success rate in unemployed bees, as would be expected if the primary benefit of communication was to reduce search time. Rather, the increased success rate for recruits overall suggests that recruits may be visiting more consistently rewarding resources. Second, we found that that in environments where the benefits of communication were high, foragers spent longer on each foraging trip, suggesting they are either traveling farther or spending more time moving between flowers. If following dances helps reduce search time, we might expect to see unemployed recruits spending less time than unemployed scouts. However, this was not the case. In fact, recruits overall actually spent more time per trip, suggesting that dance recruits may be targeting specific, higher-quality resources that are either farther away, or consist of large flower patches. Together, these results suggest that honey bees colonies may benefit from communication primarily because it focuses foraging effort on higher quality resources.