Foothill Yellow-Legged Frog Listing Finalized: What that means for your California projects

Last month, the California Fish and Game Commission officially listed five of the six clades of the foothill yellow-legged frog as either Endangered or Threatened under the California Endangered Species Act (California ESA). This listing formalizes the protections the species has temporarily had as a Candidate for listing since July 2017. This listing significantly expands the geographic range in which the species is protected, and ranges from the southwestern corner of California, bordering Mexico, all the way to the northern Sierra Nevada in Lassen, Plumas and Butte counties. Much of the Bay Area, most of the central valley, and coastal Southern California contain the protected clades.

Which FYLF clades have been listed?

The listing decision by the CDFW has designated three clades as endangered and two clades as threatened. The endangered clades include Southwest/South Coast, West/Central Coast, and East/Southern Sierra. Threatened clades include Feather River and Northeast/Northern Sierra. The Northwest/North Coast clade has been determined to not be under any threat of extinction or endangerment in the near future.

Map of California showing Foothill yellow-legged frog listing boundaries.
5 of 6 Foothill yellow-legged frog clades have been listed as threatened or endangered per the California Endangered Species Act.

How will this foothill yellow-legged frog listing affect my project?

Projects along the western coast, central valley, and in the Sierras will be required to avoid or mitigate impacts to foothill yellow-legged frog populations. At a minimum, habitat assessment will be necessary to identify areas where FYLF are likely to occur, or where they will not or are unlikely to occur. Dudek Senior Biologist Mike Henry said, “Enlisting expertise to determine where the species won’t occur is crucial to avoid unnecessary and time-consuming survey efforts, or having to provide compensatory mitigation for impacts to non-habitat lands.” If it is determined the species is likely to occur, the project may require visual encounter surveys, larval surveys, egg mass surveys, and relocations consistent with published protocols, such as the protocol written by Dudek Senior Aquatic Ecologist Craig Seltenrich.

Monitoring of the West/Central Coast Clade

The San Jose Water Company needed to permit water diversions on various creeks in the Saratoga Creek and Los Gatos Creek watersheds. Wildlife agencies had presumed that at least five of the involved creeks provided potential FYLF habitat, and that flows in those streams must be managed to support FYLF breeding and larval development. Dudek biologists conducted detailed habitat assessments on the creeks, including monitoring of flow rates and water temperature, and found that only one of the five creeks had potential to support FYLF.

Agency staff accepted our findings, and Dudek is conducting additional monitoring of water temperature on one of the five creeks to potentially exclude flow management for FYLF on that stream as well. Henry said, “Our biologists’ knowledge of the species habitat requirements and field methods to evaluate the habitat is known by state and federal wildlife agency staff, and they trust our findings. This earned trust ensures that our clients don’t experience unpleasant surprises when consulting on their projects, avoiding risks to the project timeline.” For San Jose Water Company, this saves time and money through the duration of the project, while still facilitating increased water delivery to their customers.

Dudek has more than 12 biologists throughout California experienced in conducting foothill yellow-legged frog habitat assessment, visual encounter surveys, as well as handling and relocation of the species. For more information, contact Mike Henry.