Brandt's Cormorant (Phalacrocorax penicillatus) 



World Breeding Range 



Brandt's Cormorants are the most abundant 

 and conspicuous of the cormorants nesting on the 

 California coast. Present the length of the 

 California coast in summer, they leave areas of 

 breeding concentration on the north coast and the 

 Farallon Islands in early winter and disperse along 

 the central and southern coast (Osborne 1972, 

 DeSante and Ainley 1980). 



Brandt's Cormorants usually nest on the 

 flat tops of offshore islands or, less frequently, on 

 inaccessible mainland bluffs and cliff ledges. 

 During the breeding season, these cormorants 

 present a striking appearance with their bright 

 blue throat pouches and white feather plumes 

 on the sides of their heads. At colonies, Brandt's 

 Cormorants are opportunistic gatherers of nesting 

 material (Hunt et al. 1979). They collect nearby 

 grasses and herbaceous plants and pluck seaweeds 

 from close tidal rocks. Once nests are constructed, 

 continual additions are made, often with material 

 stolen from neighboring nests (Palmer 1962). 



Nesting adults stand on their clutches of 

 chalky blue eggs, incubating with their webbed 

 feet. The young are born without feathers, but 

 soon are covered with coal black down. Nestlings 

 feed by inserting their heads down the throats of 

 their parents and removing partly digested fish 

 remains. 



Strong swimmers and divers, Brandt's 

 Cormorants prey on various species of fish 

 (Hubbs et al. 1970, Scott 1973, Baltz and 

 Morejohn 1977). Clay (1911) has reported 



Brandt's Cormorants caught in fishing nets at 

 depths as great as 70 meters. These cormorants 

 frequently feed in large flocks, often in company 

 with other seabirds (Bent 1922). 



CALIFORNIA COLONIES 



Brandt's Cormorants usually form large 

 colonies compared to most other California nesting 

 seabirds. The largest aggregation of Brandt's 

 Cormorants is on the Farallon Islands (429 012), 

 where 28,000 birds nested in 1979 (Ainley pers. 

 comm.). At least 13 colonies contain more than 

 1,000 birds. 



Over the years, Brandt's Cormorant colonies 

 shift from one location to another (Hunt et al. 

 1979, this study). Two hundred birds were 

 recorded nesting on Casket Rock (379 009) in 

 1969; no nests were observed in 1979, but 330 

 birds nested there in 1980. Similar fluctuations 

 occurred at White Rock (379 010), "333 Point" 

 (379 032), and Arched Rock (404 006). Reasons 

 for these movements are not well understood, but 

 cormorants may have abandoned Prince Island 

 (501 004) in 1977 because of a heavy flea 

 infestation (Hunt et. al. 1979). 



HISTORICAL STATUS AND VULNERABILITY 



Brandt's Cormorant populations in the 

 Channel Islands have declined in size since they 

 were first recorded there in the late 1800's (Hunt 



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