Data and analyses for manuscript: Observing farmland bumblebee behaviour: woodlands support nesting, foraging, and mating

Description

In temperate farmland, deciduous woodlands provide resources beyond foraging that may complement those of open habitats in supporting key pollinator communities such as bumblebees. Recent studies suggest woodlands influence niche partitioning both within and between species, yet a limited understanding of how bumblebees interact with woodlands constrains effective pollinator conservation strategies. Here we investigate (1) how bumblebees utilise woodland and open habitats across different life-history phases, (2) how habitat use varies among species, and (3) whether habitat use for reproductive behaviour increases with floral availability. We compared frequencies of three key bumblebee behaviours – nest-searching, foraging, and male patrolling (mate-seeking) – between deciduous woodland and field margin habitats from mid-spring to mid-summer at nine sites across agricultural landscapes in Norfolk, England. We then related floral availability to the frequency of nest-searching and patrolling behaviours. Between the habitats, nest-searching frequencies were similar, but Bombus terrestris L. was somewhat more likely than Bombus pascuorum Scop. to closely investigate woodland microhabitats. Overall foraging frequencies were also similar until early summer but exploited floral resources in each habitat were distinct and, among species, relative frequencies of woodland foraging differed greatly. In summer, male patrolling frequency was 10.8 times higher in woodlands, an effect driven by Bombus hortorum L. and Bombus pratorum L.. In contrast to foraging frequency, nest-searching and patrolling frequencies were independent of floral availability. These results indicate that woodlands complement open habitats to support multiple life-history requirements of farmland bumblebees, with the relative importance of these habitats varying among species. They further suggest that closed-canopy woodlands – poor in floral resources – could support bumblebee reproductive requirements, while tree thinning is likely needed to support summer foraging. We conclude that the preservation and management of deciduous woodlands are key elements of farmland bumblebee conservation and, therefore, the maintenance of pollination services.

Institutions

• University of East Anglia

  England, Norwich

Categories

Funders

• Natural Environment Research Council

  UK Research and Innovation

  England, Swindon

  Grant ID: NE/S007334/1
• Woodland Trust

  England, Grantham

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