Economic foraging in a floral marketplace: Asymmetrically dominated decoy effects in bumblebees

While most models of decision-making assume that individuals assign options absolute values, animals often assess options comparatively, violating principles of economic rationality. Such ‘irrational’ preferences are especially common when two rewards vary along multiple dimensions of quality and a third, ‘decoy’ option is available. Bumblebees are models of decision-making, yet whether they are subject to decoy effects is unknown. We addressed this question using bumblebees (Bombus impatiens) choosing between flowers that varied in their nectar concentration and reward rate. We first gave bees a choice between two flower types, one higher in concentration and the other higher in reward rate. Bees were then given a choice between these flowers and either a ‘concentration’ or ‘rate’ decoy, designed to be asymmetrically dominated on each axis. The rate decoy increased bees’ preference in the expected direction, while the concentration decoy did not. In a second experiment, we manipulated ..., a)  Study system
We conducted experiments with bumblebees (Bombus impatiens) (n=103) from commercially-reared queenright colonies (n = 8) (Koppert, USA); sample sizes per colony are shown in Table S1. Colonies were maintained in small boxes (~40cm3) on 30% (w/w) sucrose solution and honeybee-collected pollen (~0.5g/day, Koppert Biological Systems, USA). We connected colonies sequentially to a flight arena (l × w × h: 122 × 61 × 61 cm), using a clear plastic tube with sliding doors to control the entry and exit of bees into the arena. The floor of the flight arena was lined with green laminate and the sides and top consisted of black mesh screens. The arena was lit from above by a 40-watt LED light placed atop the arena and the room was illuminated with fluorescent light on a 12/12-hour light/dark schedule.
b)  Experimental arrays and floral stimuli
The vertical arrays used for experiments consisted of black corrugated plastic sheets with 24 holes for ‘flowers’ arranged in a 6 × 4 grid. ..., , # Economic foraging in a floral marketplace: Asymmetrically dominated decoy effects in bumblebees

[https://doi.org/10.5061/dryad.08kprr5bb](https://doi.org/10.5061/dryad.08kprr5bb)

There are two datasets: Decoy.data.csv and decoy4data.csv

## Description of the data and file structure

#### Decoy.data.csv

The concentration of the flower chosen was used to calculate the proportion of visits to each flower type out of the total number of visits.

Column A: Bee identification (number)

Column B: Bee identification (color)

Column C: Colony identification (letter)

Column D: Date of data collection

Column E: Treatment name (Binary, Trinary 1, Trinary 2)

Column F: Treatment renamed (Binary, Concentration trinary, Rate trinary)

Column G: Visit number

Column H: Trinary number

Column I: Visit number within a trial

Column J: Flower color (B=blue, Y=yellow)

Column K: Flower state (empty or full)

Column L: Concentration of sucrose reward (20%, 30%, 40%, or 50%)

Column M: Concentration ...