This IBA refers to the northwestern slope of the Tehachapi Mountains, southeast of Bakersfield. Overlooking the southern end of the Central Valley, high ridges in this area support an extensive oak woodland ecosystem (one of the largest in the state) that includes many massive, ancient individuals. Warm summer winds sweep up from the valley floor, bringing with them abundant insect prey for the birds here, including large dragonflies that congregate in exceptionally high numbers on exposed ridges.

Updated September 2008

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Ornithological Summary

These oaks are the primary nesting habitat for what is by far the largest breeding aggregation of Purple Martins in California, and one of just a handful left in central and southern California. It is likely the largest remaining natural nesting colony of Purple Martins in North America. Brian Williams (pers. comm.) estimates close to 200 breeding pairs, on the eastern edge of the range, which is nearly 1/4 of the state population. In the mid-1980s Jesse Grantham (pers. comm.) estimated 100 pairs on Tejon Ranch. These birds are apparently selecting massive Valley Oaks, using natural and Acorn Woodpecker cavities for nest sites, while taking advantage of an absence (or rarity) of European Starlings, a major nest competitor that has been linked to Purple Martin declines throughout the West. This area appears to be of great importance to cavity-nesting birds, and was historically important for California Condor foraging. Swainson's Hawk has nested recently (SF), but its current status is not known. Tunis Canyon, which sweeps up from the Central Valley floor to the upper elevations of the Tehachapi Mountains is an important corridor for southbound migratory birds, including large numbers of Canada, White-Fronted, and Snow Geese, White Pelicans, raptors (a total of 170 Swainson's Hawks were tallied on a survey in October in the mid-1980's) swifts, and swallows. Tejon and Pastoria Canyons may also provide important corridors. The reintroduced population of California Condors now frequent their historical range in the area.

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Conservation Issues

The Tejon Ranch Company's announced development plans were the primary threat to the integrity of this large IBA as the entire IBA lies within the boundary of the Tejon Ranch. In May 2008, the Tejon Ranch Company and five conservation groups, including Audubon California announced a conservation agreement that provides for the long-term protection of the vast majority of thie IBA, as well as a long-term funding stream to support restoration, stewardship and monitoring under the auspices of the newly-formed Tejon Ranch Conservancy.


This IBA refers to the northwestern slope of the Tehachapi Mtns., southeast of Bakersfield, land that is wholly within the vast Tejon Ranch.


Nine species are found on the Tejon Ranch including scrub oak, canyon live oak, blue oak, brewer oak, tucker?s oak, California black oak, valley oak, shrubby live oak and interior live oak.

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