Drones are male honey bees. Of the three basic types of bees (queen bee, worker bee, drone bee), only drones are male and drones are only male. They perform one function and one functional only: the drone bee exists to fertilize the queen. It does not pollinate flowers, produce honey, nurse, or build hives. It also does not sting (because a honey bee stinger is a modified egg-laying organ). The drone bee is also distinct from the other types of bees in that it has a fatter body than worker bees and enormous eyes that are twice the size of worker bees and queen bees. This is so they can better see the queen during mating, which happens in flight in “drone congregation areas.” A drone bee dies after successfully mating with the queen bee. Otherwise, the typical life expectancy of a drone is about 90 days.
Drone bees are produced when the queen bee does not fertilize an egg, or by a worker bee who lays non-fertilizing eggs. A colony begins to create drones during the early spring, and drone population reaches its peak in late spring and early summer.
Although the drone bee exists only to fertilize the queen, it does contribute to the hive in one other way. All types of bees, when they sense the hive’s temperature deviating from acceptable limits, either generate heat by shivering, or exhaust heat by moving air with their wings. The drone bee shares in this task with worker bees. In some species the drone bee will also buzz around intruders in an attempt to disorient them if the nest is disturbed.
The following video, starring Isabella Rossellini as a drone bee, is a terrific, fun, and simple summary of the role of the drone bee in the hive:
The word ‘drone’ comes from the Old English “dran or dræn” meaning ‘male honeybee’. In the 16th century it was given the figurative sense of “idler” or “lazy worker,” as male bees make no honey. Alongside “dran”, Old English also used the word ‘dore’ for male bees, but its meaning was broader, as is seen in ”dumbledore,” meaning bumble bee.
Honey Bees Mating and Drone Congregation Areas
Mating between the drones and a virgin queen takes place away from the colony, in mid-air mating sites called “congregation areas.” These, are specific locations where drones wait for the arrival of virgin queens to mate with. A congregation area is typically 10-40 meters above ground, and can have a diameter of 30-200 meters. They are typically located above open ground, away from trees or hills, where flight is somewhat protected from the wind (calm winds may be helpful during mating flight). The boundaries of a congregation area are distinct- queens flying a few meters outside the boundaries are mostly ignored by the drones.
Congregation areas are typically used year after year. Since drones are expelled from a colony during the winter, and new drones are raised each spring, inexperienced drones must find these congregation areas anew. This suggests that there are some environmental cues that define a congregation area, although the actual cues are unknown. At the same time, many congregation areas do not show such characteristics, such as those located above water or the forest canopy. Some studies have suggested that magnetic orientation could play a role, since drones older than 6 days contain cells in the abdomen that are rich in magnetite.
In a congregation area, drones accumulate from as many as 200 colonies, with estimates of up to 25,000 individual drones. This broad mixing of drones is how a virgin queen can ensure she will receive the genetic diversity needed for her colony. By flying to congregation areas further away from her colony, she further increases the probability of outbreeding. A single drone will visit multiple congregation areas during his lifetime, often taking multiple trips per afternoon. A drone’s mating flight averages 25-32 minutes, but can last up to 60 minutes, before he must return to the colony to refuel with honey. While at the site, the drones fly around passively, waiting for the arrival of a virgin. When the virgin queen arrives to the congregation area, the drones locate her by visual and olfactory cues. At this point, it’s a race to get your semen in that virgin, to be genetically represented in the newly founded colony. The swarming drones, as they actively follow the queen, reportedly resemble a “drone comet”, dissolving and reforming as the drones chase the virgin queen. Drones greatly outnumber the quantity of virgin queens produced per season, so even with multiple mating by the queen; very few drones will successfully mate (estimated at less than 1 in 1000). If needed, a virgin queen can embark on multiple ‘nuptial flights’, to be sure to receive enough semen from enough drones.
[Drone congregation area description adapted from wikipedia]