A vital community science initiative, the Bumble Bee Atlas, is actively working across 21 states to gather crucial data on native bumblebees. This project relies on trained volunteers who survey, photograph, and report their sightings of these essential pollinators.

The Plight of Native Bumblebees

Bumblebees, including the yellow-faced bumblebee, are facing significant population declines across their ranges. Conservation biologist Leif Richardson of the Xerces Society for Invertebrate Conservation noted that while the yellow-faced species is relatively common, all species share common threats.

Major Threats to Bumblebee Survival

Several factors are contributing to the widespread decline of these native insects. These challenges include extensive habitat loss, the ongoing effects of a shifting climate, exposure to pesticides, disease transmission, and increased competition from managed honeybees.

The situation is particularly dire for four native California species: Crotch’s, Western, Franklin’s, and Suckley cuckoo bumblebees. As of September 2022, these four species are designated as candidate species under the California Endangered Species Act, providing them temporary legal protection.

  • Franklin’s bumblebee is federally protected as Endangered.
  • Western and Suckley bumblebees are currently under evaluation for federal Endangered Species Act protections.

Why Bumblebees Matter for Ecosystems and Agriculture

The loss of native pollinators like bumblebees poses a critical risk to overall ecosystem health. Native California flora, such as manzanita, western redbud, and various sages, depend on these insects for successful reproduction.

Furthermore, the state’s substantial agricultural sector is threatened, as many commercially important crops rely on these wild pollinators. Bumblebees themselves require plant-based foods to fuel their complex social behavior and cooperative breeding.

The Solitary Start of Social Life

Bumblebees are notable as one of North America's few social native bee species. In the spring, fertilized queens embark on a solo mission to establish a new colony, often seeking abandoned underground rodent holes for nesting.

The queen constructs the initial waxy brood cells, stocks them with pollen and nectar, and lays her eggs. Once the first workers mature, they assist the queen in expanding the colony throughout the summer. The colony cycle concludes when new queens and males emerge, with only the new fertilized queens surviving to hibernate through winter.

Richardson emphasized the solitary nature of the queen's early journey. “They have this profound sociality that goes on for just a few months, but they start out alone,” he stated. “It is a perilous one-woman journey” as they gain experience before overwintering.

How the Public Can Support Bumblebee Conservation

To combat the data deficit hindering effective conservation planning, scientists are turning to the public through the Bumble Bee Atlas. This community science project actively operates in 21 states, including California, providing volunteer training.

Joining the Bumble Bee Atlas

In Southern California, the Atlas season is commencing with online training workshops. Volunteers learn a non-lethal catch-and-release survey method to accurately document bumblebee occurrences across the region. Required equipment is minimal, including an insect net, vials, a cooler with ice, a camera, and internet access.

Richardson urged the public to address broader challenges alongside data collection. “Support pesticide reduction in agriculture, for example, by the purchasing choices you make at the grocery store,” he advised.

The simplest action individuals can take is augmenting local environments. “The easiest thing we can do is add flowering California native plants to our gardens. If enough people do that it can create significant change,” Richardson concluded.