Large bumblebees can find the best flowers

In a new study from the University of Exeter, researchers report that the biggest bumblebees take the time to memorize the location of flowers with the richest nectar. With a shorter flight range and less carrying capacity, smaller bees are not concerned with finding the best flowers.

Honeybees are known to perform “learning flights” after leaving flowers. The Exeter team discovered that bumblebees do the same thing, repeatedly looking back to memorize a flower’s location.

“It might not be widely known that pollinating insects learn and develop individual flower preferences, but in fact bumblebees are selective,” said study co-author Professor Natalie Hempel de Ibarra.

“On leaving a flower, they can actively decide how much effort to put into remembering its location. The surprising finding of our study is that a bee’s size determines this decision making and the learning behavior.”

The researchers designed an experiment in which captive bees visited artificial flowers that contained a sugar solution of varying concentrations. The experts found that, the larger the bee, the more its learning behavior varied depending on the richness of the solution.

Meanwhile, smaller bees invested the same amount of effort in learning the locations of the artificial flowers, regardless of whether the sugar concentration was high or low.

“The differences we found reflect the different roles of bees in their colonies,” said Professor Hempel de Ibarra..”Large bumblebees can carry larger loads and explore further from the nest than smaller ones.”

“Small ones with a smaller flight range and carrying capacity cannot afford to be as selective, so they accept a wider range of flowers. These small bees tend to be involved more with tasks inside the nest – only going out to forage if food supplies in the colony are running low.”

The study is published in the journal Current Biology.

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By Chrissy Sexton, Earth.com Staff Writer