DOI: 10.5061/dryad.w9ghx3g1w
title: Annual variation across functional traits: The effects of precipitation and land use on four wild bee species

description: Understanding the impacts of urbanization and climate change on organisms
 has become increasingly critical in ecology and conservation as these
 anthropogenic stressors negatively impact wildlife biodiversity,
 especially pollinators such as bees. We analyzed the demographic
 (abundance and sex ratio) and morphological (body size and wing wear)
 responses to urbanization and inter-annual variation of four common wild
 bee species across an urban gradient in Toronto, Canada. We
 observed more significant shifts in bee demography with inter-annual
 precipitation variation than with urbanization, with diverse patterns
 depending on species. The drier active season saw a decrease in abundance
 for Agapostemon virescens and Ceratina calcarata whereas Bombus
 impatiens and Xenoglossa pruinosa increased when compared to the previous
 year Wetter active seasons resulted in smaller body sizes and greater wing
 wear for all bee species examined. For larger bees (A. virescens,
 B. impatiens, and X. pruinosa), increasing urbanization resulted in
 significantly larger females only for A. virescens, whereas foraging
 effort reduced as urban intensity increased. The small, cavity-nesting
 bee, C. calcarata exhibited reduced body sizes and increased
 foraging effort with increasing urbanization. Moderate
 urbanization better supported most wild bee assemblages and morphology
 suggesting that moderate land use intensity provide green spaces and
 adequate resources for these bee species.
description: # Annual variation across functional traits: The effects of precipitation
 and land use on four wild bee species Dataset DOI:
 [10.5061/dryad.w9ghx3g1w](10.5061/dryad.w9ghx3g1w) ## Description of the
 data and file structure This supplementary file contains metadata
 information and various statistical analyses using temperature variables
 for the sample region, as well as abundance, intertegular width (body
 size), and wing wear (foraging effort) for four bee species. ### Files and
 variables #### File:
 ```Chau_et_al_2025_Ecological_Entomology_-_SupplementaryTables_-_UPDATED_Mar_04_2025.xlsx``` **Description:** ##### Supplementary Table S1 - Metadata Characteristics of the four bee species in terms of sex, trap method to obtain the bee, location of sample site, and various functional traits of the bee (sociality, nesting, diet, flight, origin (endemism), head width, wing wear, intertegular distance, and categorizations of body size. Metadata also includes impervious surface % of the sample sites and if the site is identified as low, medium, or high urban intensity. Date(DD-MMM-YYY) = the date of specimen collection Month = month of specimen collection Year = Year of specimen collection Specimen = The ID of the collected specimen Country = country the specimen was collected in Province = province the specimen was collected in City = city the specimen was collected in Locality = locality the specimen was collected in SiteID = ID of the site, labeled with L for low, M for medium, and H for high urban intensity Impervious Surface Percent = the % of impervious surface coverage within a 125 radius buffer around the sample site Family = The family the specimen belongs to Genus = The genus the specimen belongs to Species = species of the specimen Sex = F for female, M for male Urban Intensity = A qualitative categorization of urban intensity (low, medium, or high) based on % impervious surface coverage Trap Method = how the specimen was caught (pan, net, vacuum, blue vane) Sociality = the social behaviour type of the bee species (eusocial, subsocial, or solitary) Nesting = the type of nesting behaviour of the bee species (cavity or ground) Diet = diet type of the bee species (generalist or specialist) Flight = the typical phenology of the bee species during the spring/summer season; short if they are out only for a short period of time, long if they can forage for longer periods of time Origin = if the bee species is native to North America or introduced Head Width = in mm, the size of the head of the specimen Wing Wear = proxy of foraging effort, based on the average wing damage observed on both wings Intertegular Distance = in mm, a proxy of body size; measurement between the two wings Body Size = a categorization of overall body size of the species (small, medium, large) ##### Supplementary Table S2 - Weather Statistics Kruskal-Wallis analyses of various weather variables such as maximum temperature, minimum temperature, mean temperature, and total precipitation to determine if these variables varied annually, between seasons, or between sample years. Statistics are based on different time periods between the four years (2020, 2021, 2022, 2023). Sampling was done 2021-2023 but we include 2020 in case weather from previous year could impact results. Annual = all 12 months Spring = March-May Summer = June-August Fall = September-November Winter = December-February Forage Season = May-September Phenology (early) = May - July 15th (some bees come out early in the season) Phenology (late) = July 16 - September (some bees come out late in the season) Active Season = April to September (this is when bees are active) Non-Active Season = October-March (when bees are dormant in their nest, overwintering) ##### Supplementary Table S3 - Abundance Statistics Tests of difference in abundance for each bee species across the years and across urban intensity for males and females. Comparisons were done for the 4 focal species in this study: Agapostemon virescens, Bombus impatients, Ceratina calcarata, Xenoglossa pruinosa. Statistics done for all individuals, and then for males and females separately. ##### Supplementary Table S4 - Intertegular Distance Statistics Tests of difference in body size for each bee species across the years and across urban intensity for males and females. Comparisons were done for the 4 focal species in this study: Agapostemon virescens, Bombus impatients, Ceratina calcarata, Xenoglossa pruinosa. Statistics done for all individuals, and then for males and females separately. We also tested differences in body size for specific intensities (across years) or specific years (across urban intensities). Intensity: High = comparison of body size across the 3 sample years (2021-2023) only for individuals from high urban intensities Intensity: Medium = comparison of body size across the 3 sample years (2021-2023) only for individuals from medium urban intensities Intensity: Low = comparison of body size across the 3 sample years (2021-2023) only for individuals from low urban intensities Year: 2021 = comparison of body size across the 3 urban intensities (low, medium, high) only for individuals collected in 2021 Year: 2022 = comparison of body size across the 3 urban intensities (low, medium, high) only for individuals collected in 2022 Year: 2023 = comparison of body size across the 3 urban intensities (low, medium, high) only for individuals collected in 2023 ##### Supplementary Table S5 - Wing Wear Statistics Tests of difference in wing wear for each bee species across the years and across urban intensity for males and females. We also tested differences in wing wear for specific intensities (across years) or specific years (across urban intensities). Intensity: High = comparison of wing wear across the 3 sample years (2021-2023) only for individuals from high urban intensities Intensity: Medium = comparison of wing wear across the 3 sample years (2021-2023) only for individuals from medium urban intensities Intensity: Low = comparison of wing wear across the 3 sample years (2021-2023) only for individuals from low urban intensities Year: 2021 = comparison of wing wear across the 3 urban intensities (low, medium, high) only for individuals collected in 2021 Year: 2022 = comparison of wing wear across the 3 urban intensities (low, medium, high) only for individuals collected in 2022 Year: 2023 = comparison of wing wear across the 3 urban intensities (low, medium, high) only for individuals collected in 2023 ##### Supplementary Table S6 - Mixed-Effects Models Mixed-effects models to ascertain if increasing urbanization impacts either abundance, body size, or foraging effort in bees differently depending on their functional traits. Functional traits assessed were: * Body Size * Sociality * Nesting * Diet ##### Supplementary Table S7 - Fourth Corner RQL Analyses Fourth corner RQL to determine if increasing urbanization is tied to variation in abundance for the bees by considering their functional traits. ## Code/software All statistical analyses were conducted in R.