The western bumble bee was historically very common throughout the western United States and Canada. However, in the last 20 years it has declined by more than 90%. Disease is the probable cause.
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News of the Wild
Western bumble bee population declines sharply
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Western bumble bee ecosystem declines rapidly
COSEWIC Assessment and Status Report on the Western Bumble Bee
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Feds consider adding 10 species, including bumble bee, to
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