2(y PACIFIC COAST AVIFAUNA No. 12 



W. Anthony (1) says that during the winters of 1896, '97 and '98 he found it of 

 regular though not common occurrence about Los Coronados Islands. As these 

 birds keep well away from the shore, they are more easily overlooked than are 

 the other gulls. 



17. Larus g"laucescens Nauraann 



Glaucous-winged Gull 



Larus glaucescens (1) Grinnell, Pasadena Acad. Sci., ii, 1898, p. 6. (2) Breninger, Auk, 

 XXI, 1904, p. 219. (3) Howell and van Rossem, Condor, xiii, 1911, p. 209. (//) Wil- 

 lett, Pac. Coast Avif., 7, 1912, p. 13. (J) Cooke, U. S. Dept Agric, Bull. 292, 1915, 

 p. 27. 



A regular though not plentiful winter visitant. G. F. Breninger (3) noted 

 immature birds but no adults at San Clemente during February, 1903, and D. R. 

 Dickey, L. M. Iluey and I saw one or two immatures daily during oar visit to 

 the same locality from March 22 to April 11, 1915. J. Grinnell (i) recorded the 

 species from Catalina in December, 1897, and on May 1, 1911, A. van Rossem (3) 

 saw three individuals at close range on Santa Cruz Island. 



18. Larus occidentalis Audubon 



Western Gull 



Larus occidentalis (1) Cooper, Proc. Calif. Acad. Sci., iv, 1870, p. 79. (2) Baird, Brewer 

 and Ridgway, Water Birds N. Am., ii, 1884, p. 231. (.3) Streator, Proc. Sta. Barbara 

 Soc. Nat. Hist., i, 1887, p. 22. (//) Blake, Auk, iv, 1887, p. 329. (5) Streator, Orn. 

 & Ool., XIII, 1888, p. 53. (6) Saunders, Cat. Birds Brit. Mus., xxv, 1896, p. 258. (7) 

 Grinnell, Pasadena Acad. Sci., i, 1897, p. 23. (8) Grinnell, Pasadena Acad. Sci., ii, 

 1898, p. 6. (9) Grinnell, Pac. Coast Avif., 3, 1902, p. 12. (10) Grinnell and Daggett, 

 • Auk, XX, 1903, pp. 30, 37. (11) Breninger, Auk, xxi, 1904, p. 219. (12) Anthony, 

 Auk, xxiii, 1906, p. 135. (13) Mearns, Bull. U. S. Nat. Mus., i.vi, 1907, p. 141. (14) 

 Linton, Condor, x, 1908, p. 125. (15) Wright, Condor, xi, 1909, p. 98. (IG) Osburn, 

 Condor, xi, 1909, p. 193. (/7) Linton, Condor, xi, 1909, p. 193. (18) Willett, Condor, 

 xii, 1910, p. 173. (19) Osburn, Condor, xiii, 1911, p. 32. (20) Burt, Condor, xiii, 

 1911, p. 164. (21) Willett, Pac. Coast Avif., 7, 1912, p. 14. (22) Wright and Snyder. 

 Condor, xv, 1913, pp. 86, 89. (23) Grinnell. Pac. Coast Avjf., 11, 1915, p. 21. (2J,) 

 Cooke, U. S. Dept. Agric, Bull. 292, 1915, p. 34. 



Larus argentatus var. occidentalis (25) Henshaw, Rep. Wheeler Surv., 1876, p. 276. 



Western Gull (26) Willett, Condor, xii, 1910, p. 171. 



Permanent and abundant resident, breeding on all islands that are not in- 

 fested with foxes, and when the latter condition prevails, on the nearby detached 

 rocks. The Western Gull begins selecting a nesting site the first part of April, 

 and eggs are usually deposited during the last week in that month and first of 

 May. Some of the young are able to fly by the first of July, but, of coarse, if a 

 first set is destroyed, unfledged young may be found late in the summer. 



During the fall and winter occidentalis is a highly valued citizen, but I defy 

 anyone to visit a breeding colony and not wish, in the heat of anger, that every 

 bird of the species might drop dead. If a colony of cormorants, pelicans or 

 murres is disturbed, there is always a cloud of the larine robbers ready to pounce 

 on the unprotected eggs, and puncture as many of them as possible. They are 



