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001
California
Country/Territory Mexico,USA
Area 180,000 
Altitude 0 - 2,000m  
Priority high 
Habitat loss major 
Knowledge good 


General characteristics 

The boundaries of this EBA run from south-west Oregon (USA) through the coastal valleys and foothills of the Sierra Nevada mountains of California to north-west Baja California (Mexico). The 2,000-m contour has been used as the upper limit of the EBA, as the breeding ranges of all the restricted-range species lie between this altitude and sea-level.

The climate is Mediterranean, characterized by cool, wet winters and dry, warm or hot summers. General vegetation types include montane coniferous forest, oak forest, mixed evergreen forest, chaparral (a dense scrub 1-3 m high with many endemic plant species), coastal scrubland, grassland and riparian habitats. Overall, nearly 50% of plant species are endemic to this region (WWF/IUCN 1997).

Restricted-range species 

All the restricted-range species occur in chaparral and/or coniferous-oak forest, apart from Agelaius tricolor, which nests in large colonies in marshes.

This is a large EBA and the restricted-range species are not found throughout. Of the two most restricted species, Selasphorus sasin breeds in a narrow coastal strip from south-west Oregon through California and winters south to Mexico, with non-migratory populations on some of the offshore islands and much of the southern Californian coast. Pica nuttalli is only found in the coastal valleys and foothills of central California. The remaining species are more widespread in California and north-west Baja California, but are still judged to have breeding ranges of less than 50,000

Species IUCN Category
Allen's Hummingbird (Selasphorus sasin)  LC 
Nuttall's Woodpecker (Dryobates nuttallii)  LC 
Yellow-billed Magpie (Pica nuttalli)  NT 
California Thrasher (Toxostoma redivivum)  LC 
Lawrence's Goldfinch (Carduelis lawrencei)  LC 
Tricoloured Blackbird (Agelaius tricolor)  EN 

Important Bird Areas (IBAs)

IBA Code Site Name Country
MX102  Area San Quintín  Mexico 
MX104  Sierra de San Pedro Mártir  Mexico 
MX105  Mountain Juárez  Mexico 

Threats and conservation 

California is the most heavily populated state of the USA, and the extent and character of the natural vegetation almost throughout this region have changed dramatically in the last two centuries, a process which has included the loss, fragmentation and degradation of many wetlands and riparian and coniferous woodlands. For example, there has been a 91% loss of wetlands (due to filling and draining for urban and agricultural growth), an 89% loss of riparian woodland (due to agricultural and urban development, and river canalization and diversions), a >90% loss of native perennial grassland (through urbanization, conversion to agriculture and a conversion to non-native annual grassland mediated by overgrazing), and a >30% loss of the most diverse conifer forests (through conversion to less diverse forest-scrub, montane chaparral, and clear-felled areas (WWF/IUCN 1997).

Despite the destruction, the EBA's restricted-range species are relatively common within their remaining habitat, and none is considered threatened. There is, however, one very high-profile, non-restricted-range, threatened species which occurs in this EBA: California Condor Gymnogyps cali fornianus (classified as Critical), historically widespread but having declined rapidly throughout the twentieth century owing to direct persecution and accidental lead ingestion from carcasses, so that in the mid-1980s the remaining eight wild birds were captured to join other zoo-held stock in a captive-breeding recovery programme. In April 1997 the total population stood at 118 birds, of which 92 are in captivity at the San Diego Wild Animal Park and World Center for Birds of Prey, and 26 are in the wild, including five in northern Arizona, 17 near Cuyama valley in the Santa Barbara County region, and four in the Ventana Wilderness Area at Big Sur (L. F. Kiff in litt. 1997). Another much publicized bird is Spotted Owl Strix occidentalis (classified as Near Threatened), which relies on mature coniferous and mixed coniferous-oak forest along the Pacific coast of Canada, USA (including in this EBA) and Mexico.

There are many protected areas in this region (estimated to cover c.11%). Of particular note is Yosemite National Park (3,083

Recommended citation  BirdLife International (2014) Endemic Bird Area factsheet: California. Downloaded from http://www.birdlife.org on 27/08/2014

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