The Bee Bachelor: Male Bumblebees Make the Ultimate Escape

Bees are traditionally viewed as hardworking insects, but what most people would be surprised to know is that male bumblebees leave home and fly away without looking back. Researchers from the University of Exeter have discovered that male bumblebees make no effort to remember the nest they've come from.

Upon leaving a flower they had just discovered, male bumblebees have been observed to perform a "learning" flight that shows them turning back and looking at the flower for them to remember how to locate it again. This is a marked contrast to the lack of effort the male bumblebees show when they leave the nest as solitary adults to start their bachelor life.

Female worker bumblebees, on the other hand, work to sustain the thriving colony and always come back to the nest with nectar and pollen by performing learning flights to remember the locations of both the flowers they fly to and the nest they came from.

University of Exeter PhD student Théo Robert was the one who discovered this behavioral pattern, prompting him to try an experiment. "Out of curiosity I placed a male on a feeder and found that its departure flight looked surprisingly similar to that of bumblebee workers. I was intrigued by this observation, and so we recorded more flights of male bees to understand whether they are capable of performing learning flights, but decide to do it only at locations that are important to them."

"It will be interesting to understand what neural differences may underlie the sex-specific behavior of males and females," said senior author Dr. Natalie Hempel de Ibarra from the University of Exeter. "Female bees have a rich behavioral repertoire that is widely studied, while the behavior of males is less studied and is therefore sometimes held to be simpler. In fact, male bumblebees have to do more than just mate after they have left their natal nest."

Migration, which includes the added benefit of avoiding breeding with sisters or cousins of male bumblebees, is key to pollination since they could travel as far as six miles. "Finding queens to mate with is not easy. Darwin found that to do so the males patrol stable routes. They learn these routes and deposit pheromones on plants along the way to attract females. There is still much for us to learn about their lives."