UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Phenology, diet breadth, and persistence of the common eastern bumble bee in Vancouver's regional parks Platsko, Mary Melissa


Bees provide essential ecosystem services, and yet, their abundance, biodiversity, and health are under threat from a number of factors, including the introduction of exotic species. The common eastern bumble bee species, Bombus impatiens, was first brought to British Columbia’s Lower Mainland region for greenhouse pollination in the late 1990s. Bombus impatiens was discovered to have escaped captivity a few years later and has since become naturalized across the region. Despite B. impatiens being documented outside of greenhouses in locations around the Lower Mainland for at least 20 years, there has been little study as to how this introduced species is impacting native ecosystems. Over two field seasons, I collected data on the phenology, behaviour and plant interactions of both introduced and native bumble bees in nine regional parks in BC’s Lower Mainland. In total, I collected data from over 3000 bumble bee-plant interactions, with observations that involved 12 different species of bumble bees. Surprisingly, B. impatiens was the most commonly observed species of bumble bee in my surveys. I analyzed the phenology and plant interactions of B. impatiens and the four most abundant native bumble bees in my surveys in order to establish the degree of niche overlap between B. impatiens and common local Bombus species. I found that the abundance of B. impatiens workers peaked later in the year compared to three of the most common native Bombus, but overlapped considerably with another common native species, B. vosnesenskii. I also found that B. impatiens tended to interact with non-native plant species frequently, again, at a rate comparable to the native bumble bee B. vosnesenskii. Finally, I found that the plant community that B. impatiens tended to interact with was not significantly different from that of the four most populous native bumble bee species. My results indicate that B. impatiens has a strong temporal niche overlap with B. vosnesenskii and that further research is required to evaluate other routes of impact, including competition for nesting sites, on native bumble bees and other regional pollinators.

Item Media

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International