Why do honey bees prefer plants with many flowers?
The honey bee waggle dance, used to communicate the location of resources like food and nest sites, is a classic example of communication and social organization. Prior research has shown that this communication system seems to be particularly advantageous in environments with large, patchy resources such as blooming trees and shrubs, like the Asian tropics where honey bees first evolved. We set out to investigate whether individual foraging decisions could have evolved to reflect a preference for such large, patchy resources, because they could enhance group-level foraging efficiency even if individual foraging efficiency is low. First, to establish that honey bees prefer larger patches of flowers, we documented the visitation behavior of honey bees on natural flowering resources in California coastal sage scrub habitat at the Bernard Field Station (Claremont Colleges). We found that, within species, plants with more flowers do indeed have a higher rate of visitation per flower than plants with fewer flowers, meaning that competition on plants with more flowers is more intense. One explanation for this behavior is that honey bees may be willing to sacrifice individual efficiency for the colony’s long-term gain. To compare this hypothesis against other explanations for honey bees' preference for plants with many flowers, we also collected data on nectar content, flower density and plant height. We found that high flower density was in fact the best predictor of visitation rate, suggesting that honey bees may be choosing plants with more flowers simply because they typically also require less energy to forage from.