Coyote Creek’s Diverse Ecosystem

Coyote Creek supports a large and diverse ecosystem. Moving from south to north, we have three distinct zones:

Valley Oak Savanna

Acorns 1-2The Coyote Valley in the southern San Jose and Morgan Hill area along Coyote Creek is host to magnificent valley oaks which are the signature trees in this biome. As an extension of the riparian zone, rainfall provides most of the moisture needs for this zone and acts as an aquifer recharge. The grasslands underneath these trees is the perfect place for deer and turkeys to visit. These trees provide much needed shade and contribute to the creek areas by providing a deep and expansive root system and acorns for acorn woodpeckers and for squirrels. If you look closely, you may see the round galls, which host wasp larvae. Valley oaks are found near the creek since they do require much water, such as that in the Coyote Creek Valley.

Below the canopies of the valley, blue, and coast live oaks are a host of grasses and flowers to support the mammals and insects. Acorn woodpeckers bury food in the oak trees; tule elk eat tule reeds and grasses; coyotes and mountain lions roam across the plains eating rodents and other mammals. The trees provide haven for over 200 bird species, including hawks, steller’s jays, and sparrows.

In spring, wildflowers, such as the California poppy, lupines, yarrow, milk thistles, purple owl’s clover, blue dicks, and sticky monkey flower, provide a profusion of color but give way to the golden grasses of fall. These areas provide visitors chances to view wildlife through activities such as hiking, fishing, and birdwatching.

Riparian Zone

Typically represented by a dense tree canopy with intermittent scrub, the riparian zone is the interface between the creek and the land. Riparian habitat can be found in the mid-section of the creek’s length through San Jose, and in pockets around Morgan Hill and Gilroy. However, it continues to shrink due to urban development, including golf courses, homes, and office parks.

Coyote Creek has a mostly vibrant riparian zone with sycamore and willow groves, shrubs, and grasses. Amidst the California bay laurel and coast live oak treetops, many species of birds nest and swim along the banks of the water. The shade provided by these trees cool the water and offer fish, such as the endangered steelhead trout, and reptiles protection and temperature control for spawning and living. They also help filter the water flowing into the creek, reducing sediment runoff and settling pollutants. A natural waterway meanders, eroding the creek bed in one spot while building up soil in other areas. The root structure of the trees and plants reduce soil erosion and increase the soil biota.

Shrubs growing in this area include mugwort, blackberry, and California aster, which support food for the red fox, butterflies, beneficial insects, and other animal species. One particularly noxious plant is arundo donax or the giant reed, which chokes out native plants with its massive stands. Colorful poison oak adds additional character to the environment since it ranges from a small stalk to branch-like ropes.

Tidal Marshlands

night heron.jpg-2Situated just north of San Jose, Don Edwards San Francisco Bay National Wildlife Refuge is a sanctuary for wildlife amidst the backdrop of one of the most populated regions in the US. This area is the north end of Coyote Creek and the tidal marsh zone, where the creek drains into San Francisco Bay. The fresh and tidal marshland area allows the steelhead trout and Chinook salmon to enter the creek to spawn upstream.

The salt marsh habitat provides a unique mixture of marine and freshwater wildlife, rich with birds, such as coots and night herons. Salt marshes are resource-rich habitats that supply a variety of avian species, reptiles, and aquatic and terrestrial mammals.

Small shrubs and grassy areas provide food and cover for jackrabbits and ground squirrels. Saltgrass and pickleweed offer food and cover for the endangered salt marsh harvest mouse, which lives in undeveloped wetlands. Saltgrass has uniquely adapted to the salty soil along the edge of the Bay. Reeds and cattails provide perches for the black-crowned night heron. The willow trees on the edge of the salt marsh provide cover and nesting sites for snowy egrets and great blue herons.

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