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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The decline and conservation status of North American bumble bees

Koch, Jonathan B. 01 August 2011 (has links)
Several reports of North American bumble bee (Bombus Latreille) decline have been documented across the continent, but no study has fully assessed the geographic scope of decline. In this study I discuss the importance of Natural History Collections (NHC) in estimating historic bumble bee distributions and abundances, as well as in informing current surveys. To estimate changes in distribution and relative abundance I compare historic data assembled from a >73,000 specimen database with a contemporary 3-year survey of North American bumble bees across 382 locations in the contiguous U.S.A. Based on my results, four historically abundant bumble bees, B. affinis, B. occidentalis, B. pensylvanicus and B. terricola, have declined by 72 - 96% relative abundance across their native distribution, while B. bifarius, B. bimaculatus, B. impatiens, and B. vosnesenskii appear to be relatively stable. Finally, I provide some notes on the distribution, abundance, and frequency of Nosema bombi infections in Alaskan B. occidentalis.

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