摘要
Pollen collection is necessary for bee survival and important for flowering plant reproduction, yet if and how pollen extraction motor routines are modified with experience is largely unknown. Here, we used an automated reward and monitoring system to evaluate modification in a common pollen-extraction routine, floral sonication. Through a series of laboratory experiments with the bumblebee, Bombus impatiens, we examined whether variation in sonication frequency and acceleration is due to instrumental learning based on rewards, a fixed behavioral response to rewards, and/or a mechanical constraint. We first investigated whether bees could learn to adjust their sonication frequency in response to pollen rewards given only for specified frequency ranges and found no evidenee of instrumental learning. However, we found that absenee versus receipt of a pollen reward did lead to a predictable behavioral resp on se, which depe nded on bee size. Fin ally, we found some evide nee of mechanical con straints, in that flower mass affected sonication acceleration (but not frequency) through an interaction with bee size. In generalz larger bees showed more flexibility in sonication frequency and acceleration, potentially reflecting a size-based constraint on the range over which smaller bees can modify frequency and accelerati on. Overall our results show that although bees did not display instrumental learning of sonication frequency, their sonication motor routine is nevertheless flexible.
