Researchers from the University of California, San Diego, discovered a species of bees that "shouts" when it finds food to deter eavesdroppers from pursuing the same food source.
Elinor Lichtenberg, lead author of the study and a postdoctoral researcher at Washington State University, and her colleagues observed the stingless bees and included two species from the genus Trigonathat.
In the wild,Trigona hyalinata, a species of bees, looks for nourishment discovered by the Trigona spinipes. The former usually goes to the same food source by eavesdropping on the shouts of the former, and attempts to steal the food source.
But, in a controlled study, researchers found the Trigona hyalinata avoided visiting food sources marked by Trigona spinipes to prevent themselves from being attacked. The eavesdropping species has the ability to take over the new food source after assembling enough members, but might risk being overpowered by other species.
The researchers created three models to illustrate the bees' decision-making process. They ran the model for T. hyalinata eavesdropping on T. spinipes, T. spinipes on T. hyalinata, and Melipona rufiventris on T. spinipes. Results for all models revealed that eavesdroppers usually stay away.
"Our study provides a new way of looking at how eavesdroppers affect the evolution of animal communication signals," Lichtenberg explained in a university news release.
Lichtenberg added that eavesdroppers were supposed to be attracted by conspicuous signals, such as shouting, and would be compelled to attack. But her study proved that for bees, eavesdroppers would usually perceive the shouting of other species as a sign that they should stay away.
This study was the first to focus on the behavior of the eavesdroppers in relation to locating food sources. Earlier studies focused on mating and predator-prey relationships.
Further details of the study were published in the July 8 issue of Current Biology.
