|The Almaden property includes a number of distinct habitats, each with
its own unique resident wildlife.
Nonnative grasslandsThe designation "nonnative grasslands" refers to those grasslands occurring on nonserpentine substrates. The soils are often rather deep in these areas and support mostly nonnative grasses such as Wild Oats (Avena barbata), Ripgut Grass (Bromus diandrus), and Farmers Foxtail (Hordeum leporinum). Other common species include Black Mustard (Brassica nigra), Red-Leaf Filaree (Erodium cicutarium), and Cheeseweed (Malva neglecta).
When a grassland is not heavily grazed, it can support many animal species because it provides a food source for herbivores in the form of grasses, seeds, and weeds. During warmer months, insects, and other invertebrates are abundant and provide prey for amphibians, reptiles, birds, and mammals. Grasslands also provide shelter and nest sites for wildlife species.
Serpentine grasslandsSerpentine grasslands are those grasslands that occur on soil derived from ultramafic (serpentine) substrate. Such soils are extremely high in exchangeable magnesium and low in exchangeable calcium. In addition, many of these areas have rock outcroppings and thin soil. Therefore, although these areas support most of the nonvascular plant species common in nonserpentine grasslands, many of these species perform poorly on serpentine soils. Reduced competition from invasive species have allowed bunchgrass and other native species to grow better in serpentine areas. Some plant species occur only in serpentine areas. Common species in serpentine grassland include Wild Oats, Purple Needlegrass (Stipa pulchra), Goldfields (Lasthenia chrysostoma), California Poppy (Eschscholzia californica), and Dwarf Plantain (Plantago erecta).
Special status species occurring in the serpentine grassland include Uncommon Jewelflower (Streptanthus albidus ssp. peramoenus), and Setchell's Dudleya (Dudleya setchelii). The larval food plants of the Bay Checkerspot Butterfly, Dwarf Plantain, and Owl's Clover (Orthocarpus densiflorus), and the food plant of Oplers Longhorn Moth (Adela oplerella), Cream Cups (Platystemon californicum), are all found in this habitat.
Diablan sage scrubDiablan sage scrub is a common plant community on the eastern side of the Mount Hamilton Range. It is usually found growing on dry, steep, south-facing slopes. Found both on and off serpentine soil, this community is dominated by very few species; these include California Sagebrush (Artemisia californica), Black Sage (Salvia mellifera), Sticky Monkeyflower (Mimulus aurantiacus), and Poison Oak (Toxicodenron diversilobum). Herbaceous plants do not grow well in this community. However, California Bee Plant (Scrophularia californica) and Purple Needlegrass (Marah fabaceus) have been observed.
A great variety of birds use this habitat including Anna's Hummingbird (Calpte anna), which feeds on the flowers of California Sage (Zauschneria californica) and Sticky Monkeyflower. Raptors often seen include American Kestrel (Falco spaverius), Northern Harrier (Circus cyaneus), and Red-Tailed Hawk. Mammals include California Ground Squirrels and Coyotes. Black-Tailed Deer use the scrub habitat for cover, and venture out into adjacent nonnative grassland or serpentine grassland areas for foraging.
Leather Oak woodlandLeather Oak woodland is dominated by Leather Oak (Quercus durata), a small tree found on ultramafic soils. This species is generally seen as a chaparral plant, but since some individuals exceed 20 feet tall, they are interpreted as comprising a woodland. In addition, under story herbs are present, which is generally not true of chaparral communities. The dominant small trees are Leather Oak, California Bay (Umbellularia californica), and Big Berry Manizanita (Arctostaphylos glauca). Common shrubs include Coffeeberry (Rhamnus californica) and Toyon (Heteromeles arbutifolia). The under story contains Purple Needlegrass, Manroot, Torrey's Melic Grass (Melicatorreyana), Nuttal's Bedstraw (Galium nittallii), Indian Paintbrush (Castilleja foliolosa), and Fairy Lanterns (Calochortus albus).
This interesting plant community provides a unique assemblage of vegetation, which in turn, gives shelter to a diverse group of bird and mammals. Most of the species are typical of chaparral or scrub communities. Cavity nesting species, such as Brown Creeper (Certhia americana), Chestnut-Backed Chickadee (Parus rufescens), and Plain Titmouse (Parus inornatus) can find adequate crevices for nesting in the dense compact growth. Woodpeckers, such as Red-Naped Sapsuckers (Sphyrapicus varius), Nuttal's Woodpecker (Picoides nuttallii), and Northern Flicker (Colaptes auratus) also find adequate insect prey and nesting habitat and are expected in this type of woodland. Cooper's Hawk (Accipiter cooperii), a species of special concern of third priority, and Sharp-Shinned Hawk (Accipiter striatus) can be seen hunting over the low forest. Mammals that occur in the dense under story of brush include the Dusky-Footed Woodrat (Neitoma fuscipes), Brush Rabbit, Ringtail (Bassariscus astutus), Badger, and Striped Skunk (Mephitis mephitis).
Oak woodlandOak woodland is found on the west-facing slopes and often forms a transition between Coast Live Oak forest and other communities. It consists of Coast Live Oak (Quercus agrifolia), Valley Oak (Quercus lobata), Blue Oak (Quercus douglasii), and California Buckeye (Aesculus californicus) with a grass under story. This includes Ripgut Grass, Farmers Foxtail, Italian Thistle (Carduus pycnocephalus), and Miner's Lettuce (Montia perfoliata).
Oak woodland is some of the most diverse and productive habitat for wildlife in central California. This habitat provides nesting and foraging opportunities for many different types of birds and mammals. Common inhabitants of oak woodland are Yellow-Rumped (Audubon's) Warbler (Dendrocia coronata), Orange-Crowned Warbler, and Wilson's Warbler (Wilsonia pusilla), which are often seen or heard foraging for insects among the leaves of oaks.
Nesting habitat for the Western Bluebird has been declining in the Santa Clara Valley due to development. In order to increase the breeding potential of this species, 79 wooden nesting boxes have been installed at Almaden since 1989. Several species closely associated with the oak forest have been aided by the addition of these boxes. These species normally nest in natural cavities of dead tree limbs, but accept artificial substitutes. Observed using the boxes are Western Bluebirds, Ash-Throated Flycatchers, Violet-Green Swallows, Plain Titmice, House Wrens, and Bewick's Wrens.
Common predatory birds and mammals that hunt or rest in oak woodland include Cooper's Hawk, Sharp-Shinned Hawk, Red-Tailed Hawk, Bobcat, Coyote, Red Fox, Racoon (Procyon lotor), Striped Skunk, and Badger. These predators seek rodents, such as California Voles and Ground Squirrels, Botta's Pocket Gopher, and Black-Tailed Jackrabbit.
The oak woodland is preferred by Black-Tailed Deer as it provides a diversity of food plants and cover for reproduction. Forbs such as Clover (Trifolium spp.), Miner's Lettuce, and Phacelia (Phacelia imbricata) are important deer forage plants during the spring and summer. In addition, the mast or acorn drop in the fall is considered an important dietary component for deer, wild pigs, and turkeys in California.
Mountain Lions prefer this type of plant community as it provides sufficient cover for hunting and is usually the habitat type with the highest deer density.
Coast Live Oak forestThe Coast Live Oak forest is found in the deeper canyons and on North facing slopes. Although not widespread, it is found near the old Stiles Ranch by the Eucalyptus grove. It is dominated by Coast Live Oak and California Bay. The under story consists of shade-tolerant plants such as Poison Oak, Western Sweet-Cicely (Osmorhiza occidentilis), and California Maidenhair Fern (Adiantum jordanii).
Bird species that use this habitat include the American Robin (Turdus migratorius), White-Tailed Kite, a fully protected species in California, Brewer's Blackbirds, Common Crow, European Starling (Sturnus vulgaris), House Finch (Carpodacus mexicanus), Warbling Vireo (Vireo gilvus), and Wilson's and Yellow-Rumped (Audubon's) Warbler. Anna's Hummingbirds (Calypte anna) feed on nectar of Eucalyptus blossoms during the late spring.
Cottonwood-sycamore riparian forestThis is restricted to the edge of Arroyo Calero. It is dominated by California Sycamore (Platanus racemosa), Fremont Cottonwood (Populus fremontii), and Arroyo Willow (Salix lasiolepis). The shady under story supports Stinging Nettle (Urtica holosericea), California Tulle (Scirpus califocnicus), Iris-leaved Rush (Juncus xiphioides), and Pacific Oenanthe (Oenanthe sarmentosa).
Riparian areas are important habitats for a wide variety of animals including invertebrates, amphibians, reptiles, birds, and mammals. Trees and shrubs offer roosting areas for birds and bats. Moist soils covered with loose leaf litter offer hiding places for amphibians and reptiles. Dampness creates good habitat for insect larvae that are prey for vertebrate species. Within California, riparian areas are considered one of the most productive habitats because water availability is higher than in surrounding more arid habitats. This situation often leads to a greater diversity of organisms.
Fresh water seepThis habitat is found in open areas along streams, and around stock ponds. Common plants include Stinging Nettle, California Willow-Herb (Epilobium californicum), Umbrella Sedge (Cyperus eragrostis), Rabbitsfoot Grass (Polypogon monspeliensis), and Common Spikerush (Eleocharis macrostachya). Some seeps on serpentine contain the Mount Hamilton Thistle (Cirsium campylon).
Drainage channels and freshwater seeps provide larger birds and mammals with drinking water during the dry summer months. However, in northern California, the primary importance of these areas lies in their ability to support breeding and larval development of rare amphibian species such as the California Tiger Salamander (Ambystoma tigrinum), Western Spadefoot Toad (Scaphiopus hammondi), Red-Legged Frog (Rana aurora), Pacific Treefrog (Hyla regilla), and the California Newt (Taricha tarosa). These animals spend the summer under rocks, in moist leaf litter, under bark, in decayed logs, and in the burrows of other animals. They are most active during the winter months when water is readily available, moving to deeper ponds and quiet pools during the late winter and spring to breed and lay eggs.
Mammals such as Raccoons and Striped Skunks (Mephitis mephitis)
feed on invertebrates and other small mammals that are attracted to the
moisture and available cover.
Last Modified: Thursday, 21-Jul-2011 15:25:22 PDT