Site Visit Insights: Restoring Endangered Serpentine Plants on Coyote Ridge

October 8, 2019

1 / 7

Biologists from U.S. Fish and Wildlife Service, Creekside Science, Valley Water, and California Department of Fish and Wildlife viewing the larger population of Tiburon paintbrush at Paintbrush Canyon near the Kirby Canyon Landfill. Photo Credit: Terah Donovan/Santa Clara Valley Habitat Agency.

2 / 7

Endangered Tiburon paintbrush growing on its host plant golden yarrow at Paintbrush Canyon. Photo Credit: Joseph Terry/USFWS

3 / 7

Paintbrush Hill (foreground) at the Kirby Canyon Butterfly Preserve and Anderson Reservoir (background). Photo Credit: Joseph Terry/USFWS.

4 / 7

Photos comparing the effects of rooting by wild pigs (using their snouts to push or nudge soil and rocks repeatedly) on the largest patch of Tiburon paintbrush plants at the Kirby Canyon Butterfly Preserve on Paintbrush Hill. The photo on the left shows a healthy patch containing 75 Tiburon paintbrush plants in April 2012. The photo on the right shows the same patch of Tiburon paintbrush in July 2017 completely removed by wild pig rooting and overturning of rocks. Photo Credit: Stu Weiss/Creekside Science.

5 / 7

Joseph Terry of U.S. Fish and Wildlife Service decontaminating his shoes with isopropyl alcohol to remove the plant pathogen Phytophthora before entering the Coyote ceanothus population creation site. Photo Credit: Terah Donovan/Santa Clara Valley Habitat Agency.

6 / 7

A healthy young Coyote ceanothus shrub planted at Valley Water’s Coyote ceanothus population creation site. Photo Credit: Joseph Terry/Santa Clara Valley Habitat Agency.

7 / 7

The first flowering Coyote ceanothus plants detected at the Coyote ceanothus population creation site in spring 2019. Photo Credit: Janell Hillman/Valley Water.

❮ ❯

Site visits are critical to helping Sacramento Fish and Wildlife Office (SFWO) biologists learn more about species and their habitats. The trips often take them into areas most people do not have a chance to explore, including public and privately-owned restricted sites, as well as some remote and hard-to-reach areas. "Site visit Insights" provides a behind-the-scenes perspective of wildlife biology, featuring photographs and interesting discoveries and happenings SFWO biologists experience in the field.

Wildlife Biologists:
Joseph Terry, Senior Biologist, Sacramento Fish and Wildlife Office

Site visit location: Coyote Ridge Open Space Preserve, Santa Clara County, California

What was the purpose of the site visit?
Endangered species recovery is complicated, and seeing pilot recovery projects in the field helps biologists understand the challenges ahead and celebrate successes. I traveled to Santa Clara County’s Coyote Ridge, located between the cities of Morgan Hill and San Jose, California, to see projects that aim to recover the endangered Tiburon paintbrush and Coyote ceanothus, which are both adapted to the harsh conditions of serpentine soils.

Threats to these plants range from animals munching on them to pathogens like Phytophthora (Greek for “plant destroyer”). Biological limitations, such as seed production, dispersal and germination, also play a role in the plants’ recovery. Pilot studies in the area seek to determine the threats and limitations of these endangered plants and to create a population of at least 2,000 Coyote ceanothus shrubs that are capable of reproducing on their own.

The Tiburon paintbrush is known from only seven occurrences, two of which are in Santa Clara County (Paintbrush Canyon and Paintbrush Hill) and separated by about 1 mile. The Paintbrush Canyon population is larger (∼ 1,900 plants) with no signs of herbivory due to the steepness of the slope that protects the plants from being eaten by cattle and wild pigs. The Paintbrush Hill population is smaller (<200 plants) and on a gentler slope with signs of herbivory by cattle and prior damage from rooting by wild pigs (using their snouts to push or nudge soil and rocks repeatedly). Creekside Science installed cages around some of the Tiburon paintbrush plants at Paintbrush Hill to test whether it would increase the size of the population. At Paintbrush Canyon, they are seeding the site from plants raised in their nursery.

The Coyote ceanothus is known from only three occurrences, all in Santa Clara County. The Santa Clara Valley Habitat Conservation Plan / Natural Community Conservation Plan requires the protection of five occurrences of the Coyote ceanothus and allows for the creation of new occurrences if other populations are not found. Valley Water implemented a pilot study in 2014 to create a new population of Coyote ceanothus on Coyote Ridge.

Where did you go?
We visited three sites on Coyote Ridge: Paintbrush Canyon, Paintbrush Hill and the adjacent Valley Water property overlooking Anderson Reservoir.

What partners were you working with and what is the nature of SFWO’s partnership with them?
This visit was led by the Santa Clara Valley Habitat Agency, Creekside Science and Valley Water and attended by biologists from the California Department of Fish and Wildlife and the U.S. Fish and Wildlife Service who are on the Technical Advisory Committee for the Santa Clara Valley Habitat Conservation Plan/Natural Community Conservation Plan. Creekside Science has years of experience researching, restoring and monitoring the Bay checkerspot butterfly, Tiburon paintbrush and other endangered serpentine plants in Santa Clara County. Valley Water is a co-permittee in the Santa Clara Valley Habitat Conservation Plan/Natural Community Conservation Plan, leads the pilot study and creation of a new occurrence of the Coyote ceanothus, and owns the Paintbrush Hill and Coyote ceanothus pilot study sites. The Kirby Canyon Landfill, owned by Waste Management, Inc., supports efforts to monitor and restore the threatened and endangered serpentine plants and wildlife at Paintbrush Canyon and its adjacent Kirby Canyon Butterfly Preserve on Paintbrush Hill.

What did you learn from this site visit that you didn’t know before?
The Tiburon paintbrush plants in the caged plots at Paintbrush Hill showed signs of decreased herbivory and had higher numbers of flowering stalks and fruits than in uncaged plots. However, there was no significant difference in the number of Tiburon paintbrush plants between the caged and uncaged plots. Therefore, some effect other than herbivory was limiting the number of Tiburon paintbrush plants at the Paintbrush Hill site. The growth of invasive grasses was noticeably higher in the caged plots which might have hindered the growth of new Tiburon paintbrush plants. Tiburon paintbrush is a root parasite. Adapted to the serpentine soils, it attaches to the roots of host plants such as common yarrow and golden yarrow to extract water and nutrients. Creekside Science was able to increase the number of Tiburon paintbrush plants in some areas at the Paintbrush Canyon site by strategically planting seeds in areas with suitable host plants and appropriate soil moisture conditions.

What surprises did you encounter during the site visit?
Valley Water carefully researched the site conditions and requirements of the Coyote ceanothus before installing nursery-grown container plants in 2014 to begin the pilot study. Unfortunately, the plants began to show signs of stress and died soon after planting. Valley Water determined that the Coyote ceanothus seedlings that had been grown in a nursery became infested with the plant pathogen Phytophthora, which kills hundreds of species of plants and caused Sudden Oak Death in California and the potato blight in Ireland. However, Phytophthora was not known to be lethal to the Coyote ceanothus. Valley Water removed all the Phytophthora-contaminated Coyote ceanothus planting basins in the fall of 2014 and used various methods to decontaminate the soil, which was completed in September 2018. By 2019, the pilot study had successfully created 389 planting basins that are occupied with at least one healthy Coyote ceanothus seedling or shrub. Four shrubs already produced flowers, which was quicker than the expected. This is the first time a new population of this species has ever been created. Valley Water prevents the reintroduction of Phytophthora into the Coyote ceanothus site by requiring all people to scrub soil off their shoes and spray their shoes with a 70% solution of isopropyl alcohol. Valley Water also implements measures to control plant diseases whenever working in Coyote ceanothus stands or other habitats that are susceptible to Phytophthora.