The benefits of communication in pollen-foraging honey bees
In groups of cooperatively foraging individuals, communication may improve the group’s performance by directing foraging effort to where it is most useful. Honey bees (Apis mellifera) use a specialized dance to communicate the location of floral resources. Because individual bees spend a longer time dancing for more rewarding resources, communication could shift the colony’s foraging effort towards higher quality resources, and thus narrow the spectrum of resource types used. To test the hypothesis that dance communication changes how much honey bee colonies specialize on particular resources, we manipulated their ability to communicate location, and assessed the relative abundance of different pollen taxa they collected. This was repeated across five natural habitats that differed in floral species richness and spatial distribution. In three of those habitats, we also marked individual bees and videotaped them within an observation hive, so that we could assess how pollen foraging success might depend on whether an individual follows a dance before leaving the hive.
Contrary to expectation, impairing communication did not change the number or diversity of pollen (resource) types used by individual colonies per day. However, colonies with intact dance communication were more consistent in their resource use, while those with impaired communication were more likely to collect rare, novel pollen types. This suggests that communication plays an important role in shaping how much colonies invest in exploring new resources versus exploiting known ones. Furthermore, colonies that did more exploration also tended to collect less pollen overall, but only in environments with greater floral abundance per patch. In such environments, the ability to effectively exploit highly rewarding resources may be especially important. At the individual level, we found that foragers that followed dances brought back larger loads of pollen, suggesting that dance communication does help colonies exploit rich resources more effectively. This could help explain how communication benefits honey bee colonies, and also why it does so only under certain environmental conditions.