Santa Clara River Overflights [2025 Update]

Please read the updated guidance regarding Santa Clara River overflights published by The Nature Conservancy for 2025. –SoCal Rotors

Bird Nesting Season Notice [PDF / map included]

Subject: Notice Regarding Federally Listed Species in the Santa Clara River, Ventura County, California

The purpose of this letter is to inform you that we believe helicopters originating from the Van Nuys Airport may be flying below 500 feet elevation along the Santa Clara River on properties owned by The Nature Conservancy in Ventura County. Witnesses allege that they have observed helicopters landing or flying immediately above ground level amongst the riparian vegetation. At issue are the potential adverse effects of such activities on the federally endangered least Bell’s vireo (Vireo bellii pusillus) and southwestern willow flycatcher (Empidonax traillii extimus), as well as other sensitive species known to occur within the Santa Clara River. These activities could constitute violations of the Federal Endangered Species Act of 1973, as amended (Act), and the Airborne Hunting Act.

The Santa Clara River possesses many of the historical attributes of lowland coastal southern California rivers, including a broad, dynamic floodplain and extensive riparian vegetation, which is ideal habitat for the least Bell’s vireo and southwestern willow flycatcher. Concerned property owners and organizations together with Federal, State, and local governmental agencies have spent over 23 years working to protect endangered species and their habitats from human-related disturbance. The Santa Clara River is vital to these species as it supports most of the breeding least Bell’s vireos and southwestern willow flycatchers in Los Angeles and Ventura Counties. The Santa Clara River is important because it also promotes least Bell’s vireo population expansion and recolonization into the Central Valley and the Central Coast drainages of California (i.e., the Santa Clara River is a considered as a “stepping stone” to both the Central Valley and Central Coast drainages). Low-flying helicopters were first reported over the Santa Clara River during 2005, concurrent with the breeding season for least Bell’s vireos and southwestern willow flycatchers (March 15 through September 15).

Aircraft flying within 500 feet of the ground during breeding season in occupied habitat for least Bell’s vireos and southwestern willow flycatchers could harm or harass these federally protected species. Low flying aircraft may cause these species to abandon breeding territories, eggs, and chicks. Abandoned eggs and chicks become susceptible to extreme temperatures (high or low), predation, and turbulence created by the helicopter rotors. Repeated flushing of least Bell’s vireos and southwestern willow flycatchers also places excessive energy demands on adults that could result in their deaths. Photographs taken by witnesses have documented helicopters flying less than 10 feet above the ground within breeding habitat for these species along the Santa Clara River. This disturbance may result in fewer birds nesting along the Santa Clara River, or complete abandonment of the site, creating a further obstacle to recovery for these threatened and endangered species. The enclosed map depict areas, cross-hatched in red, where pilots should fly no lower than 500 feet above the ground, unless the pilots are in an emergency situation.

We are seeking your assistance, along with that of other helicopter operators and owners in the vicinity, in gaining the cooperation of all helicopter pilots to avoid flying below 500 feet in elevation over least Bell’s vireo and southwestern willow flycatcher breeding and foraging sites in Ventura County during breeding season, March 15th to September 15th. Avoidance of these areas is important not only to ensure compliance with Federal law but also to assure that ongoing efforts to conserve these species are not undermined.

If you have any questions regarding this letter or if you are seeking technical assistance, please contact me at 805-880-0523.

Sincerely,

Dana Slomiak, Stewardship Coordinator for The Nature Conservancy

Santa Clara River and Coast Project
Ventura Field Office
1094 E Main St., Suite B
Ventura, CA 93001
http://nature.org/California
(805) 642-0345