The study suggests that male bees swarm together in specific aerial locations to find and attempt to mate with queens. The researchers found that drones also move between different congregation areas during a single flight.

Drones have one main purpose in life, to mate with queens in mid-air. Beekeepers and some scientists have long believed that drones gather in huge numbers of up to 10,000 in locations known as 'drone congregation areas'. Previous research has used pheromone lures to attract drones, raising concerns that these lures could have inadvertently caused these congregations. This new study is the first ever attempt to track the flight paths of individual drones and observe them in the absence of lures.

Similar mating sites, in which large numbers of males gather, have been observed in other animals but this is the first time males have been observed to move between multiple locations, hinting at the discovery of a new type of animal mating system.

The research is published today in the journal iScience and coincides with the UN designated World Bee Day (20 May), which aims to raise awareness of the importance of pollinators, the threats they face and their contribution to sustainable development.

To track the flight paths of drones, researchers attached a small antenna-like electronic device, known as a transponder, to the back of individual honeybees. When the transponder receives a radar signal from the transmitter, it absorbs its energy and converts it into a higher frequency signal, which is then detected by the radar antenna. As the transponders signal is twice the frequency of the initial signal, it is easily identifiable and cannot be confused with reflections of the original signal from objects in the surrounding environment, such as trees of buildings.