CDFW Issues Comprehensive Additional Guidance For Candidate Bumble Bee Species

On August 3, 2026, the California Department of Fish and Wildlife (CDFW) published Considerations for Conserving Crotch’s Bumble Bee, Franklin’s Bumble Bee, Western Bumble Bee, and Suckley’s Cuckoo Bumble Bee (the “2026 Guidance”) — a 44-page guidance document that substantially expands the agency’s prior June 6, 2023, Survey Considerations for CESA Candidate Bumble Bee Species (the “2023 Survey Guidance”). Importantly, the 2026 Guidance does not replace the 2023 Survey Guidance — it supplements it. Projects must comply with both documents, which together establish CDFW’s comprehensive expectations for projects in or near candidate bumble bee habitat.

The four covered bee species are currently candidates for listing under the California Endangered Species Act (CESA). CESA strictly prohibits the “take” of all candidate species without explicit take authorization, which typically requires an incidental take permit (ITP).

Although both documents expressly characterize their requirements as “non-regulatory” and “non-mandatory,” the 2026 Guidance’s inclusion of Appendix A, which reproduces actual ITP permit conditions from existing CESA permits, effectively establishes the operational standards CDFW will apply going forward. The guidance also introduces critical new timelines: Survey plans must be submitted to CDFW at least 60 days before any ground-disturbing activities, and pre-construction surveys must be completed no more than three weeks before initiating covered activities. Seasonal construction windows are narrow and may require phased work schedules, particularly for Southern California projects where Queen Flight Season begins as early as late February. Given these constraints, early consultation with CDFW Regional Offices is essential before finalizing project timelines.

Suggested Measures Under 2026 Guidance

The 2026 Guidance’s Appendix A contains example avoidance and minimization measures that will likely serve as baseline conditions for ITP applications. Notable measures include:

• Survey and Planning Timelines. Survey plans must be submitted to CDFW at least 60 days prior to any ground-disturbing activities. Pre-construction surveys must be completed no more than three weeks before initiation of covered activities. Multi-year survey protocols are now required for phased or long-duration projects.
• Revised Overwintering Survey Position. Precautionary measures are now required during the overwintering period (October 31–March 1), reversing the 2023 position that surveys were “not recommended” during this period.
• Construction-Phase Requirements. The 2026 Guidance prohibits ground and vegetation disturbance during the Colony Active Period, Gyne Flight Season, and Queen Flight Period. These seasonal periods vary by species, location, and climatic conditions, although they generally fall in the spring (January–April) and fall (July–October). For Southern California projects involving Crotch’s bumble bee, the highest detection period is April 1–June 30, and Queen Flight Season can begin as early as late February. During construction, a Designated Biologist must remain onsite and conduct daily visual surveys during periods of active bumble bee activity. Projects must maintain a default 50-foot no-disturbance buffer around confirmed nests. To confirm nest inactivity before buffer reduction, a minimum of one hour per day of nest senescence monitoring for three consecutive days is required. If an active nest is unearthed, a relocation protocol must be in place and followed.
• Additional Operational Requirements. The 2026 Guidance also addresses pesticide use (requiring CDFW written approval), mandatory environmental awareness training, restoration standards (native species with overlapping bloom periods), mowing restrictions (12-inch minimum blade height), and apiary setbacks (at least one mile from candidate species habitat).
• Expanded Habitat Assessment (Rescinded). Appendix A initially included language requiring project proponents to assess habitat within and up to 20 miles of the project area to evaluate the likelihood of bumble bees. However, CDFW has since confirmed that this 20-mile habitat assessment language was included in Appendix A in error and is being removed. According to CDFW, such assessments belong in the project planning stage to help inform project proponents on potential risk and whether to consult with the Department, rather than as an ITP permit condition.

Practical Implications

Project developers should engage legal counsel and CDFW early, budget for a Designated Biologist during active season construction, and plan for phased work schedules on multi-year projects. Construction budgets should account for biologist fees, mitigation costs, and buffer and relocation expenses.