Marin County, CA Animal Ordinances: Bird Protection (2026)
Key Facts
- Governing section
- § 22.20.040(G)
- General nesting season
- February 1 to August 15
- Trigger
- Biological assessment finds high nesting probability
- Buffer method
- Orange construction fencing around nest tree
- Northern Spotted Owl buffer
- 500 yards (§ 22.20.040(H))
Summary
When a biological assessment finds a high chance of nesting birds on a construction site, Section 22.20.040(G) of Marin's Development Code requires work that could disturb them, tree removal, grading, or other site disturbance, to happen outside the February 1 to August 15 nesting season or clear a pre-construction survey and buffer zone first.
G.Nesting Bird Protection Measures (excluding Northern Spotted Owl). For the purposes of protecting nesting birds, outdoor construction activity that involves tree removal, grading, or other site disturbances in an area where a biological assessment has identified a high probability of the presence of nesting birds are subject to the requirements enumerated below before and during site preparation and construction activities, unless separate project mitigation measures have been adopted that override these requirements.1.Construction activities that may disturb birds shall be conducted outside the nesting season, which generally occurs between February 1 and August 15.2.If commencing construction activities between August 16 and January 31 is infeasible and ground disturbance or tree removal needs to occur within the nesting season, a pre-construction nesting bird survey of the property shall be conducted by a qualified biologist.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 2026 Update 1).
Full Breakdown
040(G), 'Nesting Bird Protection Measures (excluding Northern Spotted Owl),' applies to outdoor construction activity involving tree removal, grading, or other site disturbances wherever a biological assessment has identified a high probability that nesting birds are present, unless a separate mitigation plan already covers the issue. The default is to schedule the disturbing work outside the nesting season, which the ordinance describes as generally running February 1 through August 15. If work between August 16 and January 31 isn't feasible and ground disturbance or tree removal has to happen during nesting season, a qualified biologist must run a pre-construction survey; if no nests turn up, construction can start within one week.
If active nests are found, a disturbance-free buffer zone goes up around the nest tree until the young fledge, marked with orange construction fencing that keeps machinery and workers out, though grading and construction outside the marked buffer can proceed without restriction once the fencing is in place. County staff can check the fencing during routine site inspections. The biologist has to document the survey, and if fencing is required, photos of it right after installation go to the County. 040(F), protects roosting bats found during tree removal between March 1 and October 15.
Violations & Fines
Because the bird protection measures are conditions tied to the Building Permit or environmental review approval for the project, removing the required buffer fencing or disturbing an active nest without a biologist's clearance is a permit violation under Section 22.122.030, exposing the project to a Stop Work Order; violating that order is a misdemeanor. Disturbing an active nest can also separately violate the federal Migratory Bird Treaty Act, which the County's biological-assessment trigger is designed to help projects avoid.
Frequently Asked Questions
When does Marin County's nesting bird rule kick in?
What if I have to do the work during nesting season?
Is the Northern Spotted Owl handled differently?
What happens if I disturb a nest anyway?
Sources & Official References
Other rules in Marin County
California rules heatmap·Compare Marin County to another location·View the California animal ordinances overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.