Once a year in the Australian outback, giant bees have brutal battles on the arid claypans.
In fact, so desperate are the males to mate with the few emerging females that they regularly kill each other in combat to get the chance, and occasionally some of the females get caught in the crossfire too.
These hot-blooded battles have been caught on film for the next episode of Natural Born Rebels: A Nature Miniseries, airing on PBS on May 9.
The insects in question are known as Dawson’s burrowing bees (Amegilla dawsoni). While each bee will dig its own nest into the hard ground of the arid claypans of Western Australia, the females will frequently aggregate in massive communities, sometimes with up to 10,000 individuals. By mating only once in their breeding season, intense competition is fostered among the males, which enter into a frenzy of fighting that ends in death for every single male.
Every year, the males emerge from their burrows a few weeks before the females and start to patrol the colony of females. It is thought that for every female burrowing bee, there are hundreds of males.
But not all the males look the same, with the sex being dimorphic in size. Some of the males grow much larger and are known as the majors, while many other males remain smaller and become the minors. It is only the majors that cruise the claypans, fighting furiously to mate with newly emerging virgin females. Sometimes the combat between major bees gets so intense that the females they are battling for get torn apart.
Rarely among bees, the females are not selective in any way with who they mate with. She releases a scent that drives the males into a complete and utter frenzy, turning on each other with brutal and deadly results. Only one will manage to carry her off and mate, after having wiped out many others.
The minors, on the other hand, stay out of the fray and patrol the margin on the lookout for any females that managed to sneak past the majors. Curiously, even though up to 90 percent of all females will mate with the larger major bees, they only make up roughly 20 percent of the males.
Following the destructive fray, any male that has not been killed by his compatriots simply die. For the rest of the year, the females will live fairly harmoniously, before laying their brood into burrows, and the cycle starts all over again.
Watch the bees in action in Natural Born Rebels: A Nature Miniseries episode The Mating Game, airing on May 9 on PBS at 8/7c.