Year of Award


Document Type


Degree Type

Master of Science (MS)

Degree Name

Systems Ecology

Department or School/College

W.A. Franke College of Forestry and Conservation

Committee Chair

Diana Six

Commitee Members

Janene Lichtenberg, Jim Elser


Bombus, pollinator, resource selection probability function, bumble bee, nutrient, floral resources


University of Montana

Subject Categories

Entomology | Plant Biology


Bumble bees (Hymenoptera: Bombus) are important pollinators in temperate ecosystems worldwide with seasonal caste variations involving queens, workers, and drones. Like all organisms, they must meet their nutrient requirements for successful growth and development by using several floral resources over time. When resource use is in greater proportion to its abundance on a landscape, that use is considered selective. To examine resource use within the context of abundance, a resource selection probability function (RSPF) was applied to examine floral resource use through a flowering season by a common bumble bee, Bombus vancouverensis. The RSPF framework was used to examine 1) resources used to meet nutritional requirements, 2) resources used by each caste, and 3) resources used during periods of high diversity. From June 3-August 10, 2022, floral resource abundance and phenology, and resource use by B. vancouverensis was collected at two sites in Western Montana, USA. Seven generalized linear models (GLM) were fit to examine early season (ES) and late season (LS) foraging. B. vancouverensis demonstrated selective use of two species during ES, and four species during LS. Selective use of these species may be the due to the superior or complementary nutrient profiles compared to other available resources. The use of RSPF in this study provides insights into resource use by B. vancouverensis and can be applied to other native pollinators and bumble bee ecology more generally. As land use alters floral resource availability and diversity and climate change and invasives alter plant community composition, understanding resource use may be crucial to bumble bee conservation.



© Copyright 2022 Rebekah Brassfield