1317 BIRDS OF THE SOUTHERN CALIFORNIA ISLANDS 27 



particularly fond of newly hatched cormorants and will gulp thein down witii 

 the utmost satisfaction. Tf the youngster is too large or if it happens to be a pel- 

 ican chick instead, they will just as cheerfully peck a hole in its skull just to be 

 doing something. A. AV. Anthony {12) saw one pull an adult C'assin Anklet 

 t'l-oin a shallow lioh', and swallow it with the same relish that it did the egg a mo- 

 ment later, and he has watched them in the act of dismembering half grown cor- 

 morants. As a rule, however, this destruction takes place only when a human in- 

 truder invades the colonies ; if we would deny ourselves the pleasure of walking 

 through these in the nesting season, it would certainly help to put the economic 

 value of oecidcntalis on the right side of the ledger. 



19. Larus argentatus Pontoppidan 



Herring Gull 



Larus argentatns (1) Grinnell, Pasadena Acad. Sci., ii, 1898, p. 7. (2) Dawson, Condor, 

 XVII, 1915, p. 204. 



Probably of regular occurrence in winter. On April 5, 1915, I noted two 

 adults of this species at San Clemente, and during the following week, one or 

 two were seen daily about the harbor. J. Grinnell (1) found that it was present 

 in small numbers at Catalina during December, 1897, and secured one specimen. 

 While at Santa Cruz Island in April, 1915, W. L. Dawson (2) saw two of these 

 birds at close range. 



20. Larus californicus Lawrence 



California Gull 



Larus californicus (/) Grinnell, Pasadena Acad. Sci., i, 1897, p. 23. (2) Breninger, Auk, 

 XXI, 1904, p. 219. (3) Linton, Condor, x, 1908, p. 82. (//) Osburn, Condor, xi, 1909, 

 p. 136. (J) Willett, Pac. Coast Avif., 7, 1912, p. 14. {(>) Cooke, U. S. Dept. Agric, 

 Bull. 292, 1915, p. 41. 



Undoubtedly commmon about all the islands during the winter months. C. 

 B. Linton (.5) says they were common at San Clemente during January and Feb- 

 ruary, 1907 ; and during the latter part of ^larcli and first of April, 1915, in the 

 same locality, D. R. Dickey, L. j\I. Huey and I noted them daily in company with 

 the Western Gulls. A. van Rossem saw several at Santa Cruz Island April 24, 

 1911, and C. B. Linton (MS) has taken speciemns there. 



21. Larus delawarensis Ord 



Ring-billed Gull 

 Larus delarcarensis (/) Howell and van Rossem, Condor, xiii, 1911, p. 209. 



As on the mainland, this species is probably almost as common in winter as 

 the last, but in some plumages it is so difficult to distinguish between the two 

 that it is impossible to determine their relative abundance. I have seen a few in- 

 dividuals at Catalina in April, and during the same month, 1911, A. van Ros- 

 sem and 1 positively identified several at Santa Cruz Island. 



