Bandwagon effects in a floral market: early pollinator acquisition offsets colour disadvantages in less attractive flowers

Kawaguchi, Lina 1 2 ; Ohashi, Kazuharu2; Konuma, Akihiro3; Toquenaga, Yukihiko2

Published Jan 14, 2026 on Dryad. https://doi.org/10.5061/dryad.qfttdz0qv

Data files

Jan 14, 2026 version files 22.74 KB

Abstract

Flowers with striking colours or scents are often considered to have an advantage in the competition for pollinators. However, if pollinators copy others to avoid exploration costs in changing environments, less attractive flowers may benefit from acquiring early visitors by drawing more subsequent visitors and offsetting their colour disadvantage. Previous studies provide partial support for this view, but mostly focus on pollinator behaviour at small spatial scales rather than on plant benefits in the field.

To investigate whether flowers benefit from acquiring early visitors in attracting subsequent pollinator visits, we conducted a semi-outdoor experiment in a large flight arena designed to replicate the significant information-gathering costs encountered in field conditions. By simulating a typical scenario where bumble bees are motivated to shift from a flower species with declining resource quality to newly blooming ones, we assessed the impact of early arrivals—mimicked by dead bees placed on flowers—on subsequent pollinator attraction.

When there were no early arrivals, bees showed a preference of approximately 90% for one of the two new flower colours presented. However, when early arrivals were placed in one of the patches, bees were strongly attracted to the occupied patch as well as to the one with their innately preferred colour. Notably, when their innate colour preferences and the presence of early arrivals conflicted, the two factors either canceled each other out or the preference was even slightly stronger for early arrivals. In other words, floral attractiveness was the primary cue when no other bees were present, whereas the late arrivals gave equal weight to early visitors. This shift in bees’ foraging decisions may partly reflect changes in how they sample new floral options.

Our results suggest that less attractive flowers may have a similar or even higher fitness than those with attractive colouration by gaining a head start in pollinator acquisition. This effect would be especially pronounced if the presence of conspecifics triggers a snowball effect on the choices of subsequent foragers. The use of social information by pollinators may thus represent an overlooked selective force driving the evolution of early flowers, highlighting a more multifaceted and dynamic role of pollinators in this process.

https://doi.org/10.5061/dryad.qfttdz0qv

Description of the data and file structure

This dataset contains three CSV files that describe the results of cage experiments conducted in our study. We investigated how the presence or absence of early-arrived conspecifics on newly emerged flower patches affects bees’ decision for the next foraging target with different floral colors.

1) CageExpData.csv

Raw data of the bee’s final patch choice and the patch first approached or landed on in each trial. The followings are the explanation of each column.

BeeID: ID of the test bee.
Colony: ID of the colony that the test bee belonged to.
Choice: Bee’s patch choice for the next foraging target (P: Purple, Y: yellow, O: orange, B: blue). For each bee, the patch that it preferentially visited (i.e., spent more time landing and collecting nectar) during more than 60% of trips (i.e., 9 or more out of 15) was considered the bee’s final choice. NA means that the focal bee did not shift from the old white flower patch to the newly emerged patch.
Treatment: Type of the treatment. UU means the control treatment where no early forager was present in either of the new flower patches. OU/UO means the early arrivals treatment where five fresh dead bees were added to either of the newly emerged patches. Order of the characters (OU/UO) indicates which patch was assigned to the “occupied” (or “unoccupied”). For example, the combination of OU and PY means that the early arrivals were present on the newly emerged patch with purple flowers.
ColourPair: Combination of flower colours used for the newly emerged patches in the test session. PY means purple vs. yellow, while OB means orange vs. blue.
FirstApproach: The patch each bee approached first during the test phase.
FirstLanding: The patch each bee landed first during the test phase.

2) Approach_to_Landing.csv

Raw data on the numbers of approaches and landings on flowers in each newly emerged flower patch during the experiment. The followings are the explanation of each column.

BeeID: ID of the test bee.
AppOnly: Total number of approaches to the flowers in each patch during the test phase that did not result in a landing.
Landed: Total number of landings on the flowers in each patch during the test phase.
InnPref: Whether the flower colour was innately preferred or not (0: innately less preferred colour, 1: innately preferred colour).
EarlyArrivals: Whether the early arrivals were present on the patch or not (0: no early arrivals, 1: early arrivals present).
ColourPair: Combination of flower colours used for the newly emerged patches in the test session. PY means purple vs. yellow, while OB means orange vs. blue.

*Total number of approaches to the flowers in each patch can be obtained by adding AppOnly and Landed.

3) ConsecutiveLandings.csv

Raw data on the numbers of consecutive landings on flowers in each newly emerged flower patch during the experiment. The followings are the explanation of each column.

BeeID: ID of the test bee.
Trip: Serial number of bee’s foraging trip (bout).
Landings: Number of consecutive landings on the flowers in each patch. In this dataset, as long as a bee continues visiting flowers within the same patch, we regarded landings as continuous even if they were separated by only-approach sequences. In other words, when a bee moved to the patch of white flowers or to the other newly emerged patch, we regarded the continuity of landings as interrupted.
InnPref: Whether the flower colour was innately preferred or not (0: innately less preferred colour, 1: innately preferred colour).
EarlyArrivals: Whether the early arrivals were present on the patch or not (0: no early arrivals, 1: early arrivals present).
ColourPair: Combination of flower colours used for the newly emerged patches in the test session. PY means purple vs. yellow, while OB means orange vs. blue.