Does the Flower Constancy of Bumble Bees Reflect Foraging Economics?
Article first published online: 13 OCT 2004
Volume 110, Issue 10, pages 793–805, October 2004
How to Cite
Gegear, R. J. and Thomson, J. D. (2004), Does the Flower Constancy of Bumble Bees Reflect Foraging Economics?. Ethology, 110: 793–805. doi: 10.1111/j.1439-0310.2004.01010.x
- Issue published online: 13 OCT 2004
- Article first published online: 13 OCT 2004
- Received: February 14, 2004 Initial acceptance: April 19, 2004 Final acceptance: June 17, 2004 (S. K. Sakaluk)
We examined the effects of floral reward level and spatial arrangement on the propensity of bumble bees to exhibit flower constancy. In three separate experiments, we compared the flower constancy of bees on dimorphic arrays of blue and yellow flowers that differed either in reward concentration, reward volume, or inter-flower distance. Overall, flower choice patterns varied among bees, ranging from random selection to complete constancy. When flowers contained greater reward volumes and were spaced farther apart, bees showed less flower constancy and more moves to closely neighbouring flowers. Changes in reward concentration had no effect on flower constancy; however, more dilute rewards produced shorter flight times between flowers. In addition, there was a strong positive relationship between degree of flower constancy and net rate of energy gain when flowers were spaced farther apart, indicating that constant bees were more economic foragers than inconstant bees. Together, these results support the view that the flower constancy of pollinators reflects an economic foraging decision.