Wild bumblebees use both absolute and relative evaluation when foraging

Foraging theory assumes that animals assess value based on objective payoffs, however, animals often evaluate rewards comparatively, forming expectations based on recent experience. This form of evaluation may be particularly relevant for nectar foragers such as bumblebees, where individuals can visit thousands of flowers daily that vary in nectar quality. While many animals, including bees, demonstrate reference-based evaluation in experimental contexts, it is unclear whether this occurs in the wild. Here we asked how daily experience with wildflower nectar influenced wild bumblebees’ reward evaluation. We measured the daily nectar concentration of bee-visited wildflowers (Penstemon spp.), before presenting foragers with conspecific flowers filled with a range of artificial nectar concentrations. We recorded bees’ acceptance of artificial nectar, probability of subsequent visits to flowers on the same plant, and residence time. While bees had a minimum threshold of nectar acceptability..., We collected data in June 2021 at two sites in montane meadow and mixed conifer forests. The first site was in the Humboldt-Toiyabe National Forest (Dog Valley Meadow, California), which was lower elevation and bloomed earlier. The second site was in Tahoe National Forest (Van Norden, California). Experiments were conducted using the four most abundant species of bumblebee (n=180): Bombus vosnesenskii (n=88), B. vandykei (n=16), B. centralis (n=52), B. vancouverensis nearcticus (n=5). We focused on two flower species within the genus Penstemon: P. rydbergii at Dog Valley and P. heterodoxus at Van Norden. Each testing day, we calculated the average concentration of nectar in Penstemon in the study meadow, before offering foraging bumblebees Penstemon plants containing artificial nectar that varied across a range of concentrations. This allowed us to determine whether bees’ acceptance of nectar rewards varied based on their short-term foraging experience. To calculate wildflower nectar co..., , # Absolute and reference-based evaluation in wild bumblebees

There are four annotated datasets: Fielddata.xlsx, field_data_accept.xlsx, field_data_visit.xlsx, nectar_data.xlsx

## Description of the data and file structure

In Fielddata.xlsx, acceptance and visitation are coded as proportional data. This dataset was used to generate several of the main figures.

Table of contents for field_data_visit

* Column A: bee identity - factor
* Column B: day number of experiment - continuous
* Column C: date of data collection - factor
* Column D: location of data collection - factor
* Column E: time interval for data collection - continuous
* Column F: time of day of data collection - continuous
* Column G: experimental treatment concentration (%) - continuous
* Column H: number of florets visited on previous flower - continuous
* Column I: average number of florets visited on previous flowers - continuous
* Column J: number of florets visited including revisits - contin...