At the Mitsui Ranch Preserve, we actively study and monitor several species of native amphibians throughout the property. This uniquely biodiverse site is home to threatened species including the California red-legged frog, the foothill yellow-legged frog, and the California giant salamander. As part of our mission at Mitsui Ranch Preserve, we are tracking these species over time, partly as a measure of ecosystem success. Amphibians are well known as indicator species, species whose presence in the environment can be a measure of ecosystem health, as amphibians can be sensitive to environmental pollutants and/or changes. As indicator species, the status of these amphibians provide insight about the success of our management efforts.
To monitor these species, data has been collected weekly since 2018, led by the preserve’s Managing Ecologist Jeff Wilcox. His work on these species has been used to not only measure ecosystem health, but also guide research efforts on the property, focusing on the conservation and natural history elements of native amphibians. We collaborate with various institutions, such as Sonoma State University, to tackle Master’s thesis projects that explore these topics.
Research
Visual surveys to hand capture frogs have been ongoing since 2018. Each week, with the help of many volunteers, ranging from students to wildlife biologists, we have measured, tagged, and monitored 100’s of frogs on the property. This has helped us collect long term data on the population sizes over time, and have been incorporated into several peer reviewed papers.
Education
Our surveys provide volunteer opportunities for students and wildlife professionals to gain hands on experience working with special status amphibians. Under the guidance of permitted professionals, volunteers learn how to identify, properly measure, and develop the skills to spot these cryptic species throughout the property.
Special Status Amphibians
California red-legged frog (Rana draytonii)
The CA red-legged frog (CRLF; Rana draytonii) is a federally threatened native frog that ranges from southern Mendocino County to Baja Mexico. Our site is home to a healthy population of CRLF, and we have been monitoring their demographic patterns since 2018.
Foothill yellow-legged frog (Rana boylii)
The foothill yellow-legged frog (FYLF; Rana boylii) is a special status amphibian that ranges from Oregon to southern CA. These frogs can be found throughout Copeland Creek and we have been collecting data on this frog alongside CRLF since 2018.
California giant salamanders (Dicamptodon ensatus)
The California giant salamander (CGS; Dicamptodon ensatus) is a species of special concern. One of the largest terrestrial salamanders in the U.S., we have been monitoring their population at Mitsui Ranch since 2022.
Survey Gallery
