Just because you're the smartest bee in the hive, doesn’t mean you’ll be any good at working. In fact, when it comes to collecting pollen, it often pays to be dumb.
New research by the Royal Holloway in London and the University of Guelph in Canada looked at how bumblebees' learning ability paired up with their foraging performance and contribution to the colony. The study is published in Scientific Reports.
Their results showed that slow-learning bumblebees foraged for considerably longer than the bees that were able to learn quickly during association-building tasks. There was also no difference in the rates of foraging between the two groups of bees, meaning the smart ones just foraged for less time and were worse at foraging overall.
"This study provides the first evidence of a learning-associated cost in the wild," Dr Lisa Evans, Plant & Food Research scientist at Royal Holloway, said in a statement. "Our results are surprising, because we typically associate enhanced learning performance and cognitive ability with improved fitness, because it is considered beneficial to the survival of an individual or group.”
The researchers looked at 85 bees from five different colonies and subjected them to a visual learning performance exam that tested how well the bees learned which colored flowers contained more pollen than others. Radio frequency identification tagging technology was used to track how quickly the bees made the association and how much pollen they collected in the wild.
When it came to adding up how much the bees had the collected, the slower bees were considerably better at collecting than the smart bees. This stands in opposition to what we tend to assume about bees, as we typically think that learning is particularly important to their success.
A previous study in 2008 produced opposite results, instead finding that fast-learning bees performed better and were more likely to keep track of which flowers held the most rewards. However, this new study disputes the validity of those results, as the current study followed the foraging performance of bees whose learning had previously been assessed, while the older study used different individuals. This, the current team say, could have swayed the results as a bumblebee's performance can vary depending on a colony's developmental stage and a worker's reproductive status.
The researchers posit a possible explanation for ther own findings: "Neural tissue is metabolically expensive to produce and maintain," Dr Evans adds. "Foraging is energy demanding, but so is learning. This may explain the significantly shorter foraging lifespan of fast-learning bumblebees."