Drone competition at drone congregation areas in four Apis species

In Apis mellifera the estimated average number of drones visiting a drone congregation area (DCA) was 11 750 +/- 2 145. Drones of the species Apis cerana, A. koschevnikovi, A. dorsata and A. mellifera, which pursued a queen dummy moving in circular course, flew in a comet shaped formation. Median numbers of drones in a comet ranged from 9 drones ( A. koschevnikovi) to 31 drones ( A. mellifera). In none of the species we observed aggression between drones. Drone density behind the queen and distance to the queen seemed to be adjusted to avoid collisions between drones. The median flight speed ranged from 2.6 m/s ( A. koschevnikovi) to 4.1 m/s ( A. dorsata). The median duration of a drone's presence in the mating comet did not exceed 2 seconds. Drones of all species had the ability of high acceleration ( 10 to 20 m/s(2)). Either by overtaking or leaving/entering the comet drones seem to compete for more promising positions. Only drones flying in a limited space of not more than 2000 cm(3) behind the queen were successful in grasping the dummy.