Black Storm-Petrel (Oceanodroma melania) 



World Breeding Range 



The Black Storm-Petrel merits the distinction 

 of being the rarest breeding seabird on the 

 California coast. They are known to nest in 

 California only at two sites in the Channel Islands 

 which together contain approximately 150 birds 

 (Hunt et al. 1979). Although Black Storm-Petrels 

 were not discovered nesting in California until 



1976 (Pitman and Speich 1976), they have been 

 known to breed in the nearby Los Coronados 

 Islands since 1898 (Anthony 1898). 



Fall dispersal from the breeding colonies is 

 generally southward .but wintering birds have 

 been observed in offshore waters from San 

 Francisco south to Ecuador. They seem to prefer 

 relatively warm ocean waters. Black Storm-Petrels 

 feed primarily on small fish and invertebrates 

 taken near the ocean surface and on garbage 

 discarded by passing ships (Anthony 1898, Willet 

 1933, Murphy 1936). 



CALIFORNIA COLONIES 



Black Storm-Petrels nest in California only 

 on Santa Barbara Island (524 008) and nearby 

 Sutil Island (524 009) in the Channel Islands 

 (Hunt et al. 1979). The population estimate of 

 150 breeding birds was deduced primarily by mist 

 net banding and recapture during several nights in 



1977 (Hunt et al. 1979). Since Black Storm-Petrels 

 nest in low densities in scattered natural crevices 

 and burrows of other species, censusing is 

 extremely difficult (Bent 1922, Palmer 1962) and 

 little is known of this bird's breeding biology. 



Additional nesting locations may exist in southern 

 California. 



Breeding Black Storm-Petrels are present 



8 kilometers south of the U.S. -Mexico border in 



Los Coronados Islands. This population is 



estimated at approximately 200 birds and appears 



"stable (Jehl pers. comm.). 



HISTORICAL STATUS AND VULNERABILITY 



The size of historical breeding populations 

 of Black Storm-Petrels in California is unknown, 

 but it seems unlikely that this species has ever 

 been common. Small numbers of breeding petrels 

 nesting on Santa Barbara Island could easily have 

 been overlooked by previous investigators (Hunt 

 et. al. 1979). 



Small peripheral breeding populations such 

 as the Channel Island colonies are extremely 

 vulnerable to extirpation (MacArthur and Wilson 

 1967). The Santa Barbara and Sutil Island 

 colonies could be destroyed by disturbance 

 either of the breeding grounds or of offshore 

 wintering areas, and care should be taken to 

 protect these sites. Population declines at the 

 more populous colonies in Mexico may have a 

 negative effect on the California colonies by 

 reducing potential breeding recruitment. Fortu- 

 nately Santa Barbara and Sutil Islands and the 

 nearest Mexican breeding islands are protected as 

 sanctuaries by their respective governments. 



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