Urbanisation represents a rapidly growing driver of land-use change. While it is clear that urbanisation impacts species abundance and diversity, direct effects of urban land-use on animal reproductive success are rarely documented. Here we show that urban land-use is linked to long-term colony reproductive output in a key pollinator. We reared colonies from wild-caught bumblebee (Bombus terrestris) queens, placed them at sites characterised by varying degrees of urbanisation from inner city to rural farmland, and monitored the production of sexual offspring across the entire colony cycle. Our land-use cluster analysis identified three site categories, and this categorization was a strong predictor of colony performance. Crucially, colonies in the two clusters characterized by urban development produced more sexual offspring than those in the cluster dominated by agricultural land. These colonies also reached higher peak size, had more food stores, encountered fewer parasite invasions and survived for longer. Our results show a link between urbanisation and bumblebee colony reproductive success, supporting the theory that urban areas provide a refuge for pollinator populations in an otherwise barren agricultural landscape.
ASamuelson_UrbanBumblebee_ColonyData
Colony totals data file with data collected from field. Lat = Latitude; Lon = Longitude; Col = Colony identifier; Site = site name; Crith_suc & Apic_suc = Crithidia bombi and Apicystis bombi positive samples; Crith_fail & Apic_fail = Crithidia bombi and Apicystis bombi negative samples; Syntretus, Crithidia, Apicystis = parasitised (binary); Countave = peak no. workers; Tot_cuck = number of B. vestalis invasions; Cu_bin = B. vestalis invasions (binary), Tot_male = toal males; Tot_gyne = total gynes; Tot_rep = total males + gynes; G/M_thorave = gyne/male mean thorax width (mm); G/M_wmass = gyne/male mean wet mass (g); G/M_dmass = gyne/male mean dry mass (g); Q_week = week queen left experiment due to death or colony moribundity; Q_died = queen died (binary); Col_death_week = week colony became moribund; Col_status = status for survival analysis; Rep_wk = Week colony produced reproductives or became moribund; Rep_status = produced reproductives (binary); Ave_temp = average temperature (C); Ave_hum = average humidity (%); Sum_prec = total rainfall during experiment (mm); LU750, LU500, LU250 & LU100 = 750m, 500m, 250m & 100m radius clustered land-use variables; Prop_... = Proportion land-use variables for each radius; ...PC1 = Principle component scores for each radius.
ASamuelson_UrbanBumblebee_WeekData
Weekly colony measurements data file with data collected from field. Week = week number; Date = date; Time= time; Col = Colony identifier; Site = site name; Site.ID = unique colony; Tot_cuck = number of B. vestalis invasions; Cu_bin = B. vestalis invasions (binary); LU750, LU500, LU250 & LU100 = 750m, 500m, 250m & 100m radius clustered land-use variables; . Lat = Latitude; Lon = Longitude; Removed = colony moribund; Count1/2/3 = Repeated worker counts; Countave = mean worker count; Q_larv = gyne larvae count; Q_pup = gyne pupae count; Q_open = emerged gyne pupae count; Q_alive = queen alive (binary); Usurper = usurper B. terrestris present (binary); Cuck_A = alive B. vestalis; Cuck_I = injured B. vestalis; Cuck_d = dead B. vestalis; Cuck_tot = total B. vestalis; ET_clos = closed egg towers; ET_open = open egg towers; Male = male count; gyne = gyne count; Dead_W = dead worker count; Pollen/Nectar = pollen/nectar present in pots (binary); Wax_cover = wax cover (N = none, P = partial, F = full); Weight = colony weight (kg); Scale_malf = scale malfunction (binary); Ave_temp = average temperature (C); Ave_hum = average humidity (%); Sum_prec = total rainfall during experiment (mm); Prop_... = Proportion land-use variables for each radius; ...PC1 = Principle component scores for each radius.
ASamuelson_UrbanBumblebee_FatData.csv
Fat analysis data file with data collected from bee samples analysed in the lab, with sheets for males, gynes and workers. Week = week number; Date = date; Col = Colony identifier; Site = site name; Sitewk = Site and week; no = bee number; Thor1/2/3 = repeated thorax width measurements (mm); Thor_ave = mean thorax width (mm); Wet_wt_whole = wet mass whole bee (g); Dry_wt_whole = dry mass whole bee (g); Dry_wt_ab_BE = dry mass abdomen before ether (g); Dry_wt_ab_AE = dry mass abdomen after ether (g); Fat_wt_g = Fat mass (g); Fat_wt_mg = Fat mass (mg); Fat_mg.mm = fat mg/mm; Prop_fat = proportion fat content
