You might expect bees that have discovered a superior nectar source to whisper the news to hive mates to keep the location secret from competitors, but some do the opposite and 'shout,' researchers say.
Not with sound, they say, but by using information-rich pheromone trails that are a 'loud' signal of where the nectar source is.
It not only tells other bees in the colony the way to the prize but discourages other outside bees from attempting to horn in, Washington State postdoctoral researcher Elinor Lichtenberg reports in the journal Current Biology.
"It tells nestmates where to find good food and hints at a larger occupying force," Lichtenburg explains, citing her study of a species of stingless Brazilian bees.
The search for nectar sources can turn fiercely competitive among some bee colonies, she says, and the study's findings demonstrate how eavesdropping by competitors can unexpectedly impact the evolution of natural signals.
In the Brazilian Trigona spinipes species, sending out confident, unmistakable signals is intended to discourage eavesdropping related species from trying to raid the source of nectar, researchers say, by announcing clearly that the nectar site will be aggressively defended.
"In this stingless bee system, with aggressive colonies jockeying for limited resources, more conspicuous food-recruitment signals indicate a higher likelihood that a resource will be harder to wrest away," says biology Professor James Nieh at UC San Diego, who oversaw Lichtenburg's research while she was a student in California.
The "shout out" detected by an eavesdropping rival bee would only be of use to it if it could recruit enough nestmates to successfully invade and take over the nectar source, Lichtenburg says, whereas a much more effectual use of the rivals' energy and time would be to simply find another, different food source.
The communication strategy employed by T. spinipes is bold and yet risky, since it has to successfully convince rival bees that it would be outnumbered in competition for the food source -- which may or not be the case, Nieh says.
"It's a signal with honest aspects and the possibility of lies," he says, noting that eavesdropping "is part of the information web, the signals and cues that surround animals and play a key role in shaping ecosystems."
Still, the researchers report, the counterintuitive strategy seems to be remarkably successful for the bee species studied, with its distinct pheromones being an effective weapon to convince competing species to stay away from desirable sources of nectar.
The warning comes across "loud and clear," the study suggests.
