Vertical Orientation and Color Contrast and Choices by Bumblebees (Bombus terrestris L.)
AbstractThe vertical inflorescences of several plant species are terminated by colorful bracts, which attract insect pollinators. The bracts contrast in color with the leaves below them, and are oriented perpendicular to the flowers on the inflorescence. We conducted laboratory experiments to determine the effects of color contrast and perpendicular orientation on the feeding choices of bumblebees. We first trained bees to feeders with color-contrasting perpendicular displays, composed of a horizontal and a vertical display component. We subsequently recorded the bees' choices among feeders that displayed only one of these cues. The bees preferred perpendicular displays that resembled the training model in the color of the horizontal component. None of them chose a color-contrasting display that was not perpendicular. We then evaluated the effects of the horizontal vs. vertical components of perpendicular displays on the bees' choices. After training bees to color-contrasting perpendicular displays, we allowed them to choose between displays that had either the same horizontal or the same vertical component as the training model. Foragers mostly oriented to the horizontal displays to which they had been trained. Our results suggest that (a) bumblebees can learn to associate three-dimensional perpendicular color-contrasting displays with food rewards; (b) these displays are processed hierarchically, with orientation dominating color contrast; (c) The horizontal component of perpendicular displays dominates the vertical component. We discuss possible implications of our findings for the evolution of flower signals based on extra-floral bracts.
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Bibliographic InfoPaper provided by The Center for the Study of Rationality, Hebrew University, Jerusalem in its series Discussion Paper Series with number dp439.
Length: 24 pages
Date of creation: Dec 2006
Date of revision:
Bee; Learning; Color Contrast; Perpendicular Orientation; Extra-Floral Display;
This paper has been announced in the following NEP Reports:
- NEP-ALL-2006-12-16 (All new papers)
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Tamar Keasar & Gad Pollak & Rachel Arnon & Dan Cohen & Avi Shmida, 2006. "Honesty of Signaling and Pollinator Attraction: The Case of Flag-Like Bracts," Levine's Bibliography 321307000000000599, UCLA Department of Economics.
- Tamar Keasar & Gad Pollak & Rachel Arnon & Dan Cohen & Avi Shmida, 2006. "Honesty of Signaling and Pollinator Attraction: The Case of Flag-Like Bracts," Discussion Paper Series dp438, The Center for the Study of Rationality, Hebrew University, Jerusalem.
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