Floral resource preference, occupancy, and detection of bumblebee species in northeastern Illinois

Schrage, Alma

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https://hdl.handle.net/2142/122066 Copy

Description

Title

Floral resource preference, occupancy, and detection of bumblebee species in northeastern Illinois

Author(s)

Schrage, Alma

Issue Date

2023-12-06

Director of Research (if dissertation) or Advisor (if thesis)

• Dreslik, Michael J
• Robinson, Jason L

Committee Member(s)

Matthews, Jeffrey

Department of Study

Natural Res & Env Sci

Discipline

Natural Res & Env Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• bumblebee
• bumble bee
• occupancy
• detection
• resource selection
• resource preference
• Illinois
• pollinator monitoring
• pollinator conservation
• pollinator

Abstract

Many pollinators, including bumblebees, are declining, and effective monitoring programs need to be developed to understand distribution and habitat preferences to better guide conservation management decisions. Without concrete information on detection probabilities, recommended survey efforts are often based on life history information for various bumblebee species, but such recommendations have not been vetted for efficacy. In Illinois, there has been a recent increase in bumblebee community monitoring due to the Federal listing of the rusty-patched bumblebee (Bombus affinis Cresson 1863). I conducted bumblebee assemblage surveys in grassland areas of nature preserves throughout northeastern Illinois and collected data on floral resource use and availability. I used compositional analysis of bumblebee floral resource use and floral availability data for floral taxa recorded on my survey transects at different preserves to identify floral preferences for bumblebee species. I determined two common bumblebee species, B. impatiens, and B. griseocollis, did not show significantly divergent preferences for floral taxa; they were significantly affected by site identity, suggesting they adapted their selection based on available resources. At larger spatial scales, six bumblebee species – B. impatiens, B. griseocollis, B. bimaculatus, B. auricomus, B. fervidus, and B. rufocinctus – showed significantly divergent foraging patch preferences, but again preference was driven primarily by site identity. As expected, due to flowering phenology, survey date was also a significant factor in foraging preference. To identify optimal survey effort, I modeled occupancy with imperfect detection for three common bumblebee species: B. impatiens, B. griseocollis, and B. auricomus. I found grassland area, survey date, observer walking speed, temperature, and observer experience were important for predicting occupancy and detection probabilities. My results suggest an optimal survey effort and a more nuanced approach are necessary for managing the floral resources of generalist pollinators with a relatively long colony lifespan and exhibiting foraging elasticity in response to habitat context.

Graduation Semester

2023-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Alma C. Schrage

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