Researchers investigating swarming signals in honeybee colonies discovered that the tooting of queen bees helps to prevent fighting within the colony as well as signaling swarming events. The research, published in Scientific Reports, is the first time that the absence of queen bee “tooting” has been identified as the trigger for the colony to release a new queen.
Virgin queens are juvenile queen bees who could become the next leader were they set free from their wax cells, an escape that can only be facilitated by worker bees. While studying how vibrations in colonies indicate swarming behavior, researchers from Nottingham Trent University observed that queens emit loud tooting sounds as they walk among their loyal subjects, a noise that is met by a chorus of quacking from the captive virgin queens.
The loud tooting of queen bees isn’t a new discovery, but exactly why they did this was poorly understood before now. Researchers of the study say the behavior plays an important role in both swarming behavior and preventing in-fighting in the colony. Their observations revealed that if half the colony swarm with the mobile queen bee, the cessation of tooting in the hive signals the workers to release one of the virgin queens. Once the new leader is free, she stops quacking and starts tooting to indicate her succession to the throne and prevent any further would-be-usurpers from being released.
Like the trumpets at a coronation, the tooting serves an important function in indicating the presence of a leader, while the quacking lets the colony know that there are still virgin bees in waiting, ready to step in if needed. When there are no captive virgin bees left, The Silence of the Quacks tells the whole colony it's time to get moving as they swarm as a whole with the last remaining queen to avoid finding themselves left behind without a leader.
The study inserted ultra-sensitive vibrational sensors called accelerometers into the heart of hives to allow them to listen in for swarming cues as non-invasively as possible. The recordings revealed that the queen’s tooting began between four and seven days after the colony’s first swarming event and was followed by a to-and-fro of tooting and quacking that went on until the final mass-swarm, triggered by the cessation of quacks, which indicated only one queen remained.
“The previous common interpretation of this duet is that it is a sizing-up exercise between the mobile and captive queens,” said Dr Martin Bencsik in a statement, lead researcher and a scientist in the university’s School of Science and Technology. “Our work provides strong evidence that the queen tooting and quacking is actually a colony-level communication to aid the worker population in the orderly co-ordination of the release of queens."