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A meadow bursts with bluish-purple and yellow blooms.
(Photo: © Scooter's Farm of Woodmont)

The Xerces Society works on a number of fronts to address the many issues that bumble bees and all pollinators face. Our approach to bumble bee conservation encompasses a coordinated effort in collaboration with partners and stakeholders that includes: research, advocating for necessary protections, establishing and communicating management guidelines, establishing and restoring pollinator habitat, and conducting outreach and education.


Causes of Decline

Bumble bees face many threats including habitat loss, disease, pesticide use, and climate change. Unlike honeybees which have large (>10,000 individuals) perennial hives, bumble bees produce smaller annual colonies (50-1,500 individuals). Due to their smaller annual population sizes, life cycle, and genetic makeup, they are uniquely susceptible to extinction.

Bumble bees commercially reared for agriculture are transmitting diseases to wild populations.

One of the biggest factors affecting all pollinators is fragmentation and loss of habitat.

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Widespread pesticide use further degrades habitat by removing flowering plants and poisoning pollinators.

Climate change is affecting bumble bees by changing bloom time and subjecting populations to fluctuating temperatures and weather extremes.

Commercially Reared Bumble Bees

A leading hypothesis for the decline of some of North America’s most imperiled bumble bees is that bumble bees commercially reared for pollination services helped amplify and spread a virulent pathogen (Nosema bombi) throughout North America to which wild bees had little resistance. Bumble bees are reared commercially for use as pollinators of agricultural crops such as greenhouse tomatoes and cranberries. It has been clearly documented that commercial bumble bees carry high pathogen loads and regularly interact with wild bumble bees near greenhouses and in open field settings, providing a clear mechanism for infection.



It has been consistently demonstrated that pesticides are having negative effects on native bees and their habitat.


Climate Change and Habitat Loss

Climate change may already be disrupting the relationships of plants and pollinators. This has the potential to shorten the reproductive season for bumble bees, particularly if late-season resources bloom earlier and reduce resources when the critical reproductive members of the colony (new queens and males) are active.

The changing climate also contributes to a larger factor associated with bee declines by fragmenting and degrading existing habitat. The loss of habitat to development, agriculture, and a changing climate is likely having a profound effect on all wild bees. Native prairies and grasslands are ideal for bumble bees, yet nearly all North American prairies and grasslands have been lost to land conversion, and what remains is heavily fragmented.


How We're Working to Protect Bumble Bees

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Seeking Protections under the Endangered Species Act

The Xerces Society has worked to gain Endangered Species Act protection for two of the most imperiled species in North America: the rusty patched bumble bee and Franklin’s bumble bee. In the fall of 2015, the rusty-patched bumble bee received a positive 90-day finding from the U.S. Fish and Wildlife Service in response to a petition authored and submitted by the Xerces Society and prominent bumble bee biologists in 2013, and subsequent lawsuit filed by the Xerces Society and NRDC in 2014. The U.S. Fish and Wildlife Service’s finding supported the assertion by the Xerces Society that the rusty-patched bumble bee is threatened with extinction as a result of diseases, habitat loss, and pesticide use. The agency is currently conducting a thorough 12-month status review of the species, and will determine whether or not this bumble bee warrants protection as an endangered species. To inform this review, the Xerces Society submitted comprehensive comments to the agency, including summaries of the recent scientific literature demonstrating the extent and type of threats that pesticide use—specifically neonicotinoid insecticide use—and diseases from managed pollinators pose to this species.


Leveraging Community Science to Expand Our Understanding of Distribution and Population Dynamics

In collaboration with several partners, we manage three community science projects: Bumble Bee Watch, which tracks and conserves bumble bees across the United States and Canada; the Pacific Northwest Bumble Bee Atlas, which collects data on species in Oregon, Washington, and Idaho; and, as of summer 2019, the Nebraska Bumble Bee Atlas.

With each project, Participants can submit bumble bee photos to a network of bumble bee experts that have been enlisted to help verify observations. On Bumble Bee Watch, we now have over 14,000 submissions⁠—with observations submitted from all 49 states that have bumble bees (only Hawaii does not) as well as all Canadian provinces and territories. These observations inform our outreach to landowners and state and federal stakeholders regarding opportunities for on-the-ground conservation work, and will help address questions about alterations to these species’ emergence times and shifts in their distribution due to climate change.


Training Land Managers, Conservationists, and Enthusiastic Volunteers

Over the past year, the Xerces Society has taught bumble bee identification and survey courses in California, Minnesota, Oregon, Massachusetts, and Washington. Over 300 agency biologists, land managers, community scientists, master gardeners, and homeowners learned about bumble bee identification, biology, ecology, conservation status, threats, conservation needs, and steps they can take to conserve bumble bees. Many of these courses were geared especially for federal biologists and provided them with training to better manage federal lands to support bumble bees and other pollinators. As a result of these courses, private and public lands in the West and Midwest have become much safer for bumble bees. Are you interested in having a bumble bee workshop near you? Contact us for more information.


Working to Ensure a Brighter Future for All Pollinators

The Xerces Society is engaged at all levels in protecting pollinators. Through education, advocacy, policy, and on-the-ground habitat restoration we are working to conserve the many pollinator species that support our ecosystems and food systems. To learn more about our pollinator conservation efforts, click here.

(Photos: Xerces Society / Sarah Foltz Jordan)