, Volume 61, Issue 2, pp 249–253

Pollen foraging by bumblebees: Foraging patterns and efficiency on Lupinus polyphyllus

  • Jared Haynes
  • Michael Mesler
Original Papers

DOI: 10.1007/BF00396768

Cite this article as:
Haynes, J. & Mesler, M. Oecologia (1984) 61: 249. doi:10.1007/BF00396768


Bumblebees foraging on vertical inflorescences start near the bottom and work upward, behavior commonly interpreted as a response to the greater amounts of nectar available in lower flowers. Lupinus polyphyllus, which produces no nectar, has more pollen available in upper flowers. Although bees are probably unable to detect this gradient, since pollen is hidden from their view, they still start low and forage upward. Therefore, we concluded that the bees' tendency to forage upward on vertical inflorescences is not tied to a reward gradient. In addition, bees use only about 15% of the flowers per inflorescence, although they could be much more efficient by visiting and revisiting every flower systematically. In general, revisits would not be penalized because most flowers contain enough pollen for several visits. Optimal foraging theory may not offer an adequate explanation for such gross inefficiency.

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • Jared Haynes
    • 1
  • Michael Mesler
    • 1
  1. 1.Department of Biological SciencesHumboldt State UniversityArcataUSA
  2. 2.Department of BiologyUniversity of PennsylvaniaPhiladelphiaUSA

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