4.2.4 - Wildlife and Fisheries

The Siri report done in 1972 contained detailed descriptions of the wildlife found on both the central campus and Strawberry Canyon. The report indicated that a significant number of species were using the Canyon at that time either as permanent residents or as migrants. The largest number of species occurred in the oak-bay woodland type (Figure 5), whereas the forest plantation types had far fewer species because of their exotic nature. 

The South Fork in the vicinity of the Faculty Glade had a high concentration of fox squirrels. This species is quite tame and congregates where people offer it food. Uncemented rock walls and hollow trees provided habitat for arboreal salamanders. Slender salamanders were also found mainly in the area above the Big Inch bypass outlet by the Faculty Club. The bird life of this shaded area included varied thrush, creeper, winter wren, and the russet-backed thrush. Both Steller and scrub jays occurred here as well as brown towhees and other less shade-dependent species. 

The lower portion of the South Fork across from Harmon Gym and the Eucalyptus Grove was a particularly favorable place to observe birds. Steller and scrub jays, juncos, brown towhees, mourning doves, and robins were conspicuous most of the year. There were also many less obvious species. Horned owls occasionally foraged and roosted in the area and were known to feed on Norway rats which are still common campus pests. Both arboreal and slender salamanders were scarce. At the present time, fox squirrels are abundant in the Eucalyptus Grove area.

In 1972; the shaded North Fork above University Drive provided habitat for bird life similar to those found near the Faculty Glade. Uncemented rock walls harbored arboreal salamanders. The upper North Fork area in Woolsey (Blackberry) Canyon provided di verse wildlife habitat for a wide variety of species. Wild mammals and birds were abundant and reflected on a smaller scale much of the variety that occurred in Strawberry Canyon at the time. Motile species such as fox, deer, mountain lion, bobcat, and coyote ranged into this area from Strawberry Canyon. Deer are presently abundant in the lower canyon most of the year as they search out sources of succulent vegetation and water. 

The diversity of animal life on the central campus has consistently diminished with the increased urbanization of the campus over the years. Wildlife found on campus today consists primarily of birds, but small mammals and nocturnal scavengers can also be found. Fox squirrels, mice, and Norway rats make up the small mammalian population. Transient nocturnal animals include raccoons, opossums, and even deer that occasionally wander down from the hills. Resident birds on the central campus include scrub jays, Stellar jays, robins, chickadees, brown towhees, mourning doves, house finches, black phoebes, starlings, and various sparrows. Migratory birds also utilize the campus area during the winter (Cicero, 1987).

Wildlife in Strawberry Canyon is associated with the various vegetation types (Figure 5). Havlik (1978) states that oak-bay woodland is the most valuable wildlife habitat in adjacent Tilden Park, but Stebbins (1975) contends that eucalyptus forests also support a wide variety of wildlife. Wildlife habitat in the eucalyptus groves depends on the density of the forest Densely planted trees have lower habitat value than more widely spaced stands. Eucalyptus flowers produce an abundant food source for birds, insects, and some mammals. A variety of birds feed on the seeds. Red-tailed hawks and horned owls commonly nest in eucalyptus as well. 

Siri reported in 1972 that Strawberry Canyon provided habitat for over 100 species of wild birds, 40 mammalian species, 12 species of lizards and snakes, and 6 species of salamanders and frogs. Today, Strawberry Canyon provides habitat for several large predatory species which are dependent on extensive undeveloped tracts of land. These include mountain lion, bobcat, coyote, golden eagle, and prairie falcon. All these species are regularly observed in Tilden Park.

The California Department of Fish and Game's Natural Diversity Data Base was consulted for listings of rare or endangered species that may occur in the watershed. Strawberry Canyon provides suitable habitat for the Alameda striped racer which is listed as threatened by California and is also a candidate for federal listing. This snake is restricted to open brushland in Alameda and Contra Costa counties and has been sighted in adjacent Claremont Canyon as well as Tilden Park. A newly discovered rare arachnid, Sitalcina sp., occurs in Blackberry Canyon below LBL. This animal inhabits grassy areas or oak savanna and requires a native overstory. It lives under rocks on well-drained slopes in developed topsoil. Undisturbed rocks are the most critical component of its habitat. Three other locally rare or unique species that occur in the Berkeley Hills are the grasshopper-sparrow, saw-whet owl, and Berkeley kangaroo rat The grasshopper sparrow is a locally depleted species found along the crests of grass-covered ridges. The saw-whet owl is a small woodland or forest-associated owl found in stands of redwood and Monterey pine. Finally, the Berkeley kangaroo rat is a locally unique species also found in the hills. None of these locally rare species has any formal listing. 

No fisheries exist in Strawberry Creek today. According to California Department of Fish and Game reports, the creek supported steelhead in the 1930's. The disappearance of fisheries over time is probably due more to the extensive physical alterations of the creek channel itself than to the degradation of water quality. Many physical barriers to fish migration such as culverts were installed. Both channelization of the creek and culverts altered the hydrology and fish habitat of the creek. Baseflow in the creek became more shallow and the water velocity increased. Areas such as pools that provided rest areas were obliterated and cover from the high winter peak flows disappeared. In addition, anadromous fish are reluctant to migrate through totally dark passages such as culverts. All these factors, in combination with the deterioration of water quality over time, resulted in the loss of fisheries in Strawberry Creek.