Gone with the wind: effects of wind on honey bee visit rate and foraging behaviour

Abstract

Wind is an important yet understudied environmental influence on foraging behaviour. We investigated the direct and indirect effects of wind on foraging worker honey bees, Apis mellifera. Bees were trained to an array of artificial flowers providing nectar rewards in a location sheltered from natural wind. To examine the direct effect, fans produced four different wind speeds between 0 and 3 m/s at three different flower spacings: 5 cm (flowers touching) and 10 cm and 20 cm (flowers not touching). To examine the indirect effect of wind moving flowers, flowers were moved 10 cm at three frequencies between 50 and 110 cycles/min at zero wind speed. We recorded the number of successful flower visits, time spent flying, search time on a flower and hesitancy to take off. Bees visited significantly fewer flowers with increasing wind speed which was caused by a significant increase in hesitancy to take off. This difference in flower visits between wind speeds was highest at the 20 cm spacing. Flower movement had no effect on foraging rate; however, there was a significant positive relationship between flower movement and the total time spent flying. This was counterbalanced by a significant reduction in time spent searching for the nectary after landing on a flower at the higher flower frequencies. Our results suggest that it is the direct effect of wind on hesitancy to take off that has the greatest effect on honey bee foraging rate.