more sub-tropical seabird community of the 

 Channel Islands, although containing fewer 

 breeding seabirds than the Farallon Islands and 

 northern California, is of no less importance. 



Six of the 23 species discussed in this catalog 

 are widespread along much of the California 

 coast. Of the six, the Black Oystercatcher is the 

 most widely distributed, despite an estimated 

 breeding population of only 1 ,000 birds. This 

 distribution reflects the abundance of this species' 

 preferred nesting habitat in California. The Black 

 Oystercatcher's small population size, however, is 

 perhaps related to its tendency to nest as isolated 

 pairs on offshore rpcks and inaccessible stretches 

 of the California coastline. 



The distributions of Pelagic Cormorants and 



Pigeon Guillemots are also relatively uniform, in 

 part because their nesting habitat is abundant in 

 this state (Figure 4). Pelagic Cormorants are most 

 numerous between Cape Mendocino and San 

 Francisco, an area possessing long stretches of 

 vertical cliffs. Pigeon Guillemots attain their 

 greatest abundance in central California, south 

 of San Francisco, including the Farallon Islands, 

 but large colonies are also found at many locations 

 north of Point Conception. Both Brandt's 

 Cormorants and Western Gulls are widely distri- 

 buted throughout California but extremely large 

 concentrations of each exist on the Farallon 

 Islands (Figure 4). Common Murres are found 

 throughout much of central and northern 

 California although they are most abundant in 



40% 



2% 



Figure 3. Percentage of breeding seabirds along 

 the California coast. Circle size is directly pro- 

 portional to numbers of birds. 



35% 



13 



