Franklin’s bumble bee added to endangered species registry
ASHLAND — The Franklin’s bumble bee will be the first bee in the western continental U.S. recognized as endangered under the Endangered Species Act, the U.S. Fish and Wildlife Service announced Monday. The rule goes into effect Sept. 23.
With the smallest range of any bumble bee in North America, the pollinator was found only in a 13,000-square-mile area of southwest Oregon and Northern California, from Sutherlin to Mount Shasta and the Cascades to Coast mountain ranges, with Mount Ashland one of the last areas where it could be found.
A single worker Franklin’s bumble bee was last observed in the Rogue River-Siskiyou National Forest — the species’ primary native habitat — in 2006 on Mount Ashland. Field surveys in 1998 identified nearly 100 bees.
According to the Rogue River-Siskiyou National Forest, “persistent threats” including disease, small population instability and pesticide use have contributed to the species’ rapid decline since the 1990s, and present-day risk of extinction.
The bees’ wild native habitat makes them highly elusive, but perhaps not extinct, the USFWS speculates. Surveyed areas have accounted for a small percentage of the species’ historic range.
Over the past 15 years, forest employees and USFWS staff perpetuated efforts to conserve and recover the species in suitable locations where the bee was last spotted, in the Siskiyou Mountains and High Cascades ranger districts, said Glenn Casamassa, USFS Pacific Northwest regional forester.
Casamassa said the conservation effort was strengthened by interagency partnerships, research and citizen-science efforts in the region, rooted in a “collective sense of urgency to protect native pollinators.”
Franklin’s bumble bees have been sighted at elevations between 540 and 7,800 feet, and the species serves as the primary pollinator for alpine flowering plants.
The bee requires ample flora and cavities for breeding and sheltering from May to September. The USFWS determined sufficient habitat exists to satisfy the bees’ needs without designating critical habitat along with the endangered species classification.
Endangered species protection opens avenues for funding and resources to “locate, monitor and conserve remaining populations” of the bee, said Leif Richardson, conservation biologist with the Xerces Society for Invertebrate Conservation.
The bees are “generalist foragers” that gather pollen and nectar from a variety of flowers, according to the Xerces Society, which first petitioned for endangered species protections in 2010, in collaboration with entomologist Dr. Robbin Thorp.
Historically, Franklin’s bumble bees have been spotted gathering pollen on lupine, California poppy, nectaring horsemint and mountain penny-royal. They rely on abandoned rodent holes for breeding and shelter habitat.
The bee’s unique pollination method is essential for tomato, blueberry and other plant production, according to the U.S. Forest Service.
“Although habitat loss has had negative effects on bumble bees, we conclude it is unlikely to be a main driver of the decline of the Franklin’s bumble bee,” the USFWS found. “While it is unlikely that pesticides alone can account for the decline of the Franklin’s bumble bee, documented effects of pesticides on closely related Bombus species suggest pesticide use was likely a factor.”
Other endangered bee species include the rusty patched bumble bee, native to eastern North America and the upper Midwest, and seven native Hawaiian species.
Reach reporter Allayana Darrow at email@example.com or 541-776-4497.