A team of scientists has discovered that male bumblebees purposefully avoid remembering the location of their birth. Once they leave home, they forget the area and never return. The findings are in a paper that was published in The Journal of Experimental Biology.
Bumblebees (Bombus terrestris) have excellent navigational skills and memories. They live in social, cooperative groups led by a queen. Males of this species leave their hive once mature to avoid mating with close relatives. Instead, they fly miles away from their birth nest to look for a new queen; their only purpose is to mate. Scientists know that female bees memorize the locations of both their nest and good areas for foraging. However, there had never been a similar study designed to test the abilities of male bees.
Researchers from the University of Exeter observed the flight behaviors of mature male bumblebees. They gave males access to artificial flowers containing a sweet nectar drink. Interestingly, after drinking the nectar, the males did the same learning “dance” that females perform. Females have a flight behavior that involves them looking back at the place to memorize it for later. This was the first time it had been observed in males, showing that male bumblebees can learn and memorize flower locations. The researchers wondered if this would extend to the location of their nest, a place they would never need to return to. After observing released males, the researchers noted that they never once turned back after flying away. In other words, male bumblebees can memorize flower locations but make no effort to remember their birthplace. This would serve an evolutionary purpose since the males should never have a reason to return home. By immediately forgetting where they had lived, the males can continue their journey and find an unrelated female to mate with.
The team’s findings provide new insights into how bumblebees learn and memorize locations. For the first time, researchers were able to provide solid evidence of male learning flights. These flight behaviors were limited to food sources, however, and not their birthplace. Although bees have been well-studied, the authors point out that we still have a lot to learn.
Robert et al. Male bumblebees perform learning flights on leaving a flower but not when leaving their nest. The Journal of Experimental Biology (2016).