Coyote Ridge Wildflower Walk 4/13/08

Coyote Ridge Wildflower Walk

Checkerspot butterfly on Bluedicks

Coyote Ridge lies east of Highway 101 between south San Jose and Morgan Hill. It is a 12 mile long, by 1 mile wide outcropping of serpentine rock. Serpentine is the state rock. What's important about serpentine is that it forms a soil that is poor in nutrients, particularly nitrogen, that non-native grasses need to thrive. Native wildflowers have evolved to be able to grow in serpentine soil, which allows them to compete against the non-native grasses. In norrmal soil, non-native grasses crowd out native wildflowers, but in serpentine soil, the natives can survive. However, automobile exhaust contains nitrogen compounds, particularly ammonia, which fertilize the soil and allow the non-native grasses to grow in the serpentine soil. Bay Area car exhaust, particularly from nearby Hwy 101 has resulted in grasses crowding out the wildflowers. Certain animal species depend on the wildflowers to survive. One of these is the bay checkerspot butterfly, a federally-listed threatened species, protected by the Endangered Species Act. There are ways to control the grasses. On Coyote Ridge, this has been done by cattle grazing. The cattle eat the non-native grasses, allowing the native wildflowers to grow. As a result, the numbers of bay checkerspot butterflies have been increasing on Coyote Ridge. Another benefit has been the spectacular display of spring wildflowers on the ridge. The ridge is normally closed to the public, but docent-led guided tours are conducted in the spring by the Silicon Valley Land Conservancy. On April 13, 2008, members of the Friends of Santa Teresa Park, New Almaden Quicksilver County Parks Association, the Santa Clara County Open Space Authority, and others took a tour of Coyote Ridge. These are pictures from that tour.

The tour began at a parking area within the Kirby Canyon Landfill. The tour follows a wide service road all the way to the top of the ridge. Here the group is heading up the hill. The flat on the left is covered with plantains.

This tiny flower is California plantain, the primary food source for the larva of the bay checkerspot butterfly.

Poppies, phacelia (larger white flowers), and popcornflowers (tiny white flowers) line the steep hillside above a canyon.

Docent Carolyn talks about the seeds of a blow-wife.

White popcornflowers, yellow desert pincushions, and orange poppies surround a greenish serpentinite rock.

Native morning glories.

While many thistles are non-native pests, this is a native Mt. Hamilton thistle. It is a rare plant, a candidate for federal endangered species status. It likes wet soil in serpentine areas and grows along seeps (like this one here) and creeks.

This mustard-like flower is the native San Francisco wallflower. The thick round leaves are actually seed pods.

This is the most beautiful jewelflower, a rare flower found on serpentine soils, also found on Coyote Peak and the Stile Ranch Trail in Santa Teresa Park

The silvery sheen on the hillside is from plantains.

Spring gold (lomatium) and California poppies grow on the rocky roadside.

The group ascends the service road above the Kirby Canyon Landfill. The Coyote Valley is in the background. The percolation ponds are along the Coyote Creek Parkway. The green area is the Coyote Creek Golf Course.

Poppies line the service road.

Poppies along the road. The hills in the background are beginning to dry up, but protected valleys are still green.

Patches of poppies can be seen in the valley below. Santa Teresa Park's Coyote Peak can be seen in the background. Santa Teresa Park has serpentine outcroppings, but since cattle grazing was banned years ago, exotic grasses have crowded out wildflowers. Checkerspot butterflies have not been seen in the park in recent years. In order to restore the habitat for the butterflies, the county is studying restoring cattle grazing in the park.

Pink serrated onions dot the side of the hill above the road.

Poppies growing on the hillside below the road.

Poppies and purple owl's clover. Owl's clover is a secondary food source for checkerspot butterfly larvae, when plantain are not available. However, they have a shorter growing season than the plantain, so they are a less desirable food source.

The Santa Clara Valley dudleya, a federally-listed endangered species, grows on the rocky slope. It is only found in the Coyote Valley.

Nearing the ridgetop, poppies and creamcups line the road. Poppies fill the adjacent valley.

On top of the ridge, the hilltops are covered with a carpet of wildflowers, mostly tidytips and goldfields. Grasses have been kept in check by grazing cattle.

Tidytips and goldfields, with Mt. Hamilton in the background.

Hillside covered with goldfields.

White creamcups, dark round purple sanicle, and yellow goldfields.

The group is having lunch in a field of goldfields. Carolyn is showing flowers to the children.

The north end of Anderson Lake, the largest reservoir in Santa Clara County, can be seen below the hills.

The tiny white flowers are muilla. The yellow flowers are goldfields.

Cattle are grazing on the hills in the distance. The Coyote Ridge has a variety of owners. Only 1300 acres of the 7000 acres on the ridge are actually protected. United Technologies, which operated a rocket plant in the valley east of the ridge, owns 5100 acres. The VTA owns 540 acres, which they set aside as mitigation for constructing Hwy 101. It is managed by the Santa Clara County Open Space Authority. The Silicon Valley Land Conservancy owns 100 acres on the ridgetop. The Kirby Canyon Landfill has 267 acres set aside as a butterfly preserve. Lion Homes has 170 acres used for mitigation. The hills and valley to the east are part of 10-mile long 28,539-acre Rancho San Felipe, the largest piece of privately held land in the county. It is owned by the Hewlett and Packard families as a private ranch, but protected from development by the donation of the land's development rights to the Nature Conservancy. In the next valley to the northeast, Hall's Valley, is 9560-acre Joseph D. Grant County Park, the largest of the Santa Clara County Parks.