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The Xerces Society applauds efforts to protect this imperiled species


Expert Contacts

Rich Hatfield, Senior Conservation Biologist, The Xerces Society
(503) 468-8405  |  [email protected]

Sarina Jepsen, Endangered Species Program Director, The Xerces Society
(971) 244-3727  |  [email protected]

PORTLAND, Ore.; Monday, August 23, 2021---Responding to a petition from the Xerces Society and Dr. Robbin Thorp, the U.S. Fish and Wildlife Service will list Franklin’s bumble bee (Bombus franklini), as an endangered species under the Endangered Species Act (ESA), making it the first bee in the western continental U.S. to be officially recognized under the ESA. This species was listed as Proposed Endangered in 2019, and this serves as the final ruling for this species, officially providing legal protections afforded by the ESA.

Franklin’s bumble bee has one of the most restricted ranges of any bumble bee in the world. It is known only from southern Oregon and northern California and its entire distribution can be covered by an oval of about 190 miles north to south and 70 miles east to west.

“Franklin's bumble bee is confined to a very small historic range in the Klamath and Siskiyou mountains at the California–Oregon border,” said Leif Richardson, Conservation Biologist for the Xerces Society, and project lead for the California Bumble Bee Atlas. “The Fish and Wildlife Service decision to list the bee as endangered will help us locate, monitor and conserve remaining populations.”

A precipitous decline began in 1999 and despite an extensive amount of searching, Franklin’s bumble bee has not been seen since 2006. The primary threats to this species include: 1) diseases from managed bees, 2) pesticides and 3) a small population size.

The Xerces Society for Invertebrate Conservation and University of California at Davis entomologist Robbin Thorp formally petitioned the U.S. Fish and Wildlife Service to protect Franklin’s bumblebee in 2010. 

Robbin Thorp conducted surveys for Franklin’s bumble bee for more than two decades and was the first person to call attention to the decline in this and other formerly common bumble bees. He was a leader in bumble bee conservation, and passed away in June of 2019. 

“We welcome this decision by the Fish and Wildlife Service to extend ESA protection to Franklin’s bumble bee,” said Sarina Jepsen, Director of Xerces Society’s Endangered Species Program. “This bee urgently needs all of the help it can get.”

While many native pollinators have suffered declines related to loss of habitat and pesticides, the sudden decline of Franklin’s bumble bee and some of its closest relatives, including the rusty patched bumble bee, was likely initiated by a pathogen that spread from managed bees. This hypothesis was first introduced by Dr. Thorp, and has been extensively tested by a team led by Dr. Sydney Cameron of the University of Illinois, who determined that commercial bumble bees were likely responsible for spreading and amplifying this pathogen across North America at a time that coincides with the disappearance of Franklin’s bumble bee. The effects of this pathogen may have been compounded by insecticide use, loss of habitat and given its restricted historic range, a small population size.  

“The decline in bumble bees like Franklin’s bumble bee should serve as an alarm that we are losing important pollinators,” said Xerces Society Executive Director Scott Black. “We hope that the story of the Franklin’s bumble bee will compel people to prevent further pollinators across the U.S. from sliding toward extinction.”

To better understand the status of all bumble bees along the West Coast, and to encourage people to continue searching for Franklin’s bumble bee, the Xerces Society and conservation partners have launched two projects to harness the volunteer power of community scientists to help map bumble bees in the Pacific Northwest and in California.

The Pacific Northwest Bumble Bee Atlas is spearheaded by the Idaho Department of Fish and Game, Washington Department of Fish and Wildlife, Oregon Department of Fish and Wildlife and the Xerces Society. The California Bumble Bee Atlas is a partnership between the California Department of Fish and Wildlife and the Xerces Society. Both atlas projects collaborate with community scientists to collect information on bumble bees in Oregon, Washington, Idaho and California.

“If we hope to find Franklin’s bumble bee again, we will need all hands on deck,” said Rich Hatfield, Senior Conservation Biologist at the Xerces Society. “Hopefully community scientists can help us rediscover this bee, and provide us with information that will allow us to better understand and implement conservation measures to protect all of our region’s most vulnerable bumble bees.”


Read Franklin’s bumble bee Petition

Read about the Pacific Northwest Bumble Bee Atlas and the specific effort to help find Franklin’s Bumble Bee

Read about the California Bumble Bee Atlas

Read about Robbin Thorp’s legacy



The Xerces Society for Invertebrate Conservation protects the natural world by conserving invertebrates and their habitat. Established in 1971, the Society is a trusted source for science-based information and advice and plays a leading role in protecting pollinators and many other invertebrates. Our team draws together experts from the fields of habitat restoration, entomology, plant ecology, education, community engagement, pesticides, farming and conservation biology with a single passion: Protecting the life that sustains us. To learn more, visit or follow us @xercessociety on Twitter, Facebook or Instagram.