Urban gardens foster year-round activity of bumble bee queens
Data files
Jul 10, 2026 version files 26.98 KB
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inat22.csv
18.32 KB
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README.md
3.62 KB
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Urban_Bombus_Data2022_23.csv
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Abstract
These data demonstrate year-round activity of the yellow-faced bumble bee (Bombus vosnesenskii). Through monthly surveys of fixed routes in San Francisco's East Bay in 2022 and 2023, we counted B. vosnesenskii queens and whether they were foraging or nest-searching. In typical bumble bee life cycles, nest-searching behavior begins in spring and lasts for about one month, before queens establish nests. In contrast, we observed 11 months of queen activity, with 8 months of nest-searching behavior. In addition to field surveys, we validated these results with iNaturalist data, hand-scoring images to caste (queen, worker, or male). In addition, we noted that four of the observed records were of mating queens and males.
Dataset DOI: 10.5061/dryad.qjq2bvqww
Description of the data and file structure
We collected field data to assess the seasonality of Bombus vosnesenksii queens in the San Francisco Bay Area. We used iNaturalist data from the same counties as our field data to contextualize the queen data with the rest of the life stages in this area. Any NA represents data not available.
Files and variables
File: Urban_Bombus_Data2022_23.csv
Description: Field survey data from 2022 and 2023 in Alameda and Contra Costa Counties in California, USA.
Variables
- Route: Identifier of which of 15 routes around Berkeley were taken. See Erickson et al. 2025 (DOI 10.1002/ecs2.70259) for more details on the routes.
- Date: MM/DD/YYYY
- Time: HH:MM in 24-hour clock
- Address: Nearest street address to location of observation
- Species: Specific epithet written. While only B. vosnesenskii was used in this paper because it was the most commonly observed species, we did observe other species occasionally. "Unk" means unknown species. Data for final presentation were filtered to only include Species == "Vosnesenskii"
- Caste: "Queen" was noted by large size and, if nest-searching, distinct behavior; "Worker" was noted for female worker bees, noted by their smaller size and female morphology. "Male" was noted for males, noted for their distinct male morphology. "Unk" was noted if caste could not be determined. For this paper,r we filtered for Caste == "Queen" as other castes were seen in such low numbers.
- Nest_search: 1 indicates nest-searching, 0 indicates not nest-searching
- Foraging: 1 indicates foraging, 0 indicates not foraging
- Note: Any notes written in the field while making the observations
File: inat22.csv
Description: iNaturalist records of Bombus vosnesenskii from 2022 within Alameda and Contra Costa Counties, California. Individual iNaturalist records are listed with the associated URL. Additionally, 'verify', 'caste', 'mating', and 'DOY' were added to the iNaturalist file. Due to licensing restrictions, the complete iNaturalist-derived dataset could not be deposited to Dryad but is available by request via email to srfinn@ucdavis.edu.
Variables
- url: iNaturalist URL for the original observation.
- verify: The ability for caste to be verified from the image. "yes" means the image was of quality to be able to verify caste and species, "unsure" means the image was not clear enough to make a judgement, "duplicate" refers to images that were clearly duplicate observations of another observation. Only observations marked as "yes" were used in the paper.
- caste: The caste score each image was given by hand. Caste designation was based on relative size and distinct morphologies of males versus females.
- mating: "yes" for visible mating in the image, "no" for no mating observed
- DOY: Day of Year, with January 1st being 1 and December 31st being 365.
Access information
Data were derived from the following sources:
- Erickson, E., C. B. Schultz, and E. E. Crone. 2025. Neither source nor trap: Urban gardens as habitat for nonmigratory monarch butterflies in Northern California. Ecosphere 16:e70259.
- iNaturalist community. Observations of Bombus vosnesenskii from Alameda County and Contra Costa Count,y California, United States observed between January 1st 2022 and December 31st 2022. Exported from https://www.inaturalist.org on April 11 2024.