Lowry et a I Food habits of Zaiophus californianus at San Clemente Island. California 515 



O 

 111 



Q. 



1981 1982 



El Nino 

 1983 1984 



1985 



1986 



1981 



1983 ' 1984 



El Nino 



Figure 5 



Seasonal percent occurrence (PO) of 9 prey taxa found in 

 1304 California sea lion scats. 1981-86. No samples were 

 collected in winter 1986. 



vidual numbers than other prey taxa, except northern 

 anchovy. During the El Nino period, pelagic red crab 

 were the second most frequently occurring prey in scat 

 samples. During the post-El Nino period, the diet was 

 dominated by northern anchovy. 



We found yearly and seasonal variability in the rela- 

 tive proportions represented by the three indices for 

 9 prey taxa examined (Figs. 5-7). Northern anchovy 

 was consistently found in scats throughout the study 



at varying occurrence, composition, and number index 

 levels. However, during summer and autumn 1984 we 

 noted a drop in the three indices compared with 1982, 

 1983, 1985, and 1986; and it did not occur as often in 

 1982 as in 1983, 1985, and 1986. Jack mackerel was 

 the most frequent prey during 1981-82, but after that 

 period it was found infrequently, represented a very 

 small proportion of the diet, and few individuals were 

 found in the scats. An increase in the occurrence of 



