The bumble bee atlas: A community science approach to pollinator conservation

Native bees face a range of threats that may lead to their imperilment, including habitat loss,

pesticide exposure, and climate change. Status assessments and conservation efforts for at-risk

species are limited by a lack of rigorously collected occurrence data, even for species in the

best-known groups, such as bumble bees (Bombus). The Bumble Bee Atlas (BBA), a project of

the Xerces Society for Invertebrate Conservation and partners, is a community science effort to

generate occurrence data for these bees across 20 US states. Using the California Bumble Bee

Atlas as an example, this talk will explore the BBA model for pollinator species inventory. Such

projects leverage the labor of trained volunteers to extend the capacity of conservation biologists

to collect information about sensitive species. Participants follow a standardized survey protocol,

and all determinations are verified by experts. Since 2017, nearly 5,000 BBA volunteers have

together submitted ~120,000 photo-vouchered Bombus observations made in >27,000

effort-limited surveys and other observations. The BBA model is flexible to enrolling large

numbers of participants, and is scalable to extensive geographic areas that individual researchers

are not able to survey alone. As BBA projects mature, we transition them to long-term

monitoring efforts centered on occupancy modeling, in which sentinel sites are inventoried

repeatedly across the growing season, allowing more fine-grained decline assessments. The

project has become the single best source of survey-based occurrence data for species status

assessments at both the state (e.g., Bombus crotchii in California) and federal level (e.g., B.

franklini endangered species designation).