The Heermann Gull 



Its breeding haunts, known to include certain islands off the coast of 

 Lower California and western Mexico, have only recently come to light, 

 and are not yet very fully mapped out. The largest colony yet described 

 is that of Ildefonso Island in the Gulf of California, in Latitude 26 

 38' north, where, in 1909, W. W. Brown, Jr., estimated that 2500 pairs 

 were nesting. Nesting takes place in March and early April, so that by 

 the last week in May returning migrants, having completed the duties 

 of reproduction, begin to appear along the coast of southern California. 

 There is a steady increase in numbers till July, at which time, and after, 

 this species outnumbers the native Westerns (Larus occidentalis) two to 

 one in southern waters. The migratory movement persists throughout 

 the summer and carries many of the species as far north as British Co- 

 lumbia; but in general it may be affirmed that they are present in a stead- 

 ily decreasing ratio anywhere north of Monterey. Heermann Gulls 

 are a little clannish, and are likely to flock by themselves even when 

 sharing their resting places with other species. Their relations with the 

 Western Gull, however, are most familiar, and they are to be found pretty 

 much wherever occidentalis goes, save that they will not go far inshore nor 

 under any circumstances venture "cross lots" to visit interior waters. 



By the end of January adult birds have assumed white heads, which 

 mark the breeding plumage, and have begun to forsake Californian waters. 

 Yet there always remain behind a sufficient number of stragglers, imma- 



tures and non-breeding birds, to 



Taken at Redondo Beach 



A TROPHY 



Photo by the Author 



H32 



