Conservation Organizations Seek Protection for California’s Endangered Bumble Bees

Crotch’s bumble bee (Bombus crotchii). (Photo- Xerces Society Stephanie McKnight) 20180622_213903 960x640
Crotch’s bumble bee (Bombus crotchii) / Photo: Stephanie McKnight, Xerces Society

Today conservation and food safety groups filed a petition with the California Fish and Game Commission to list four species of native bumble bees – the western bumble bee, Franklin’s bumble bee, Crotch’s bumble bee and the Suckley cuckoo bumble bee – as Endangered under California’s Endangered Species Act.

Bumble bees are among our most recognizable and well-loved insects. Usually yellow, black and fuzzy, they are found throughout the state. Recent studies have revealed that several bumble bee species in California are imperiled and in need of immediate conservation attention.

Along with other types of bees, bumble bees are essential to the reproduction of many of California’s specialty crops, including tomatoes, peppers, melon, squash, cotton and almonds, as well as to native ecosystems—from the flower fields of the Carrizo Plain to the montane meadows of the Sierra Nevada. Conserving a diversity of native pollinators within the state is paramount to maintaining the state’s natural heritage, as recognized in California’s new Biodiversity Initiative, which calls for fallowed agricultural land to be transformed into habitat for bees, creating a “pollinator highway” across the state. They are also essential for food production.

“Native pollinators, including bumble bees, provide ecosystem services estimated at more than nine billion dollars annually in the U.S.,” said Sarina Jepsen, director of the Xerces Society’s endangered species program and petition coauthor. “By acting on this petition, California has an opportunity to demonstrate how an individual state can lead the nation in protecting a diverse suite of pollinators, benefiting both agriculture and natural areas.”

Together, the historic ranges of the western bumble bee, Franklin’s bumble bee, Crotch’s bumble bee and the Suckley cuckoo bumble bee cover much of the state, but currently populations persist in very few areas. The western bumble bee, for example, was one of the most common bumble bees within its range prior to the late-1990s, but in California is now found only in a few sites in the Sierra Nevada and the northern coast. These four species of bumble bee are primarily threatened by habitat loss, diseases and pesticides.

“California’s native bees are essential to keep our state blooming,” stated Kim Delfino, California Program Director for Defenders of Wildlife. “Current regulations have proven insufficient to reverse the sharp decline in populations and protection under our state endangered species act is the last line of defense if we hope to keep these four bee species from going extinct.”

Protecting these species will help to maintain the healthy ecosystems that make California such a remarkable and productive state. Over 80% of all terrestrial plant species require an animal pollinator (usually an insect) to reproduce. About one-third of food production depends on pollinators, and 75% of all fruits and vegetables produce higher yields when visited by pollinators. California accounts for more than 13% of the nation’s total agricultural value, and protecting these four bee pollinators is an important component of protecting California’s agricultural legacy.

”One out of every three bites of food is dependent on pollinators such as bees,” said Rebecca Spector, West Coast Director at Center for Food Safety. “The diversity and strength of bee populations is critical to maintaining a healthy and robust food supply in California and beyond.”

Listing these bumble bees under the California Endangered Species Act will protect them from ‘take’, including activities that could cause them to go extinct, and will allow for additional conservation measures to be implemented. Efforts are already underway to restore habitat for bees on farms and in cities throughout California. An increased investment in pollinator habitat, along with protection from insecticides and pathogens, will be required to prevent extinction of these bumble bees.

Bumble Bee Profiles

Crotch’s bumble bee (Bombus crotchii), a bee with yellow, black and often orange on its abdomen, is considered Endangered by the International Union for Conservation of Nature (IUCN); it only persists in 20% of its historic range, and has declined by 98% in relative abundance (its abundance relative to other species of bumble bees). This bee historically occurred from the northern Central Valley to Baja Mexico, but currently persists primarily in southern coastal habitats and some areas to the north and southwest of Sacramento.

The western bumble bee (Bombus occidentalis occidentalis) has a range that extends across the western U.S. and southern Canada. In California, it was historically known from the northern part of the state, the coastal region, and the mountains. It currently persists primarily in the Sierra Nevada; its relative abundance has declined by 84%.

The Suckley cuckoo bumble bee (Bombus suckleyi) was historically found throughout the western U.S. As a cuckoo bumble bee, it is found only where its host species of bumble bees, including the western bumble bee, remain. It is considered Critically Endangered by the IUCN and its range has declined by 58%.

Franklin’s bumble bee (Bombus franklini), which historically occurred in an area about 60 miles wide in the Siskiyou Mountains of northern California and southern Oregon may already be extinct. Despite extensive annual surveys by Dr. Robbin Thorp, professor emeritus at the University of California–Davis, Franklin’s bumble bee has not been seen since 2006.

Reprinted from Xerces Society news release.