INTRODUCTION. 



The present list is intended to include all birds which have been so far 

 proven to occur within the limits of the region under consideration. Besides 

 their common and scientific names, brief notes are added on their comparative 

 abundance and distribution; definite dates of arrival and departure, in the cases 

 of migratory birds; the extent of the breeding season, giving exact dates and 

 citing extreme instances. 



No species or subspecies has been entered except upon the best of evidence. 

 Thus many, especially water birds, which I am certain do occur, have been ex- 

 cluded because specimens have not been actually secured and properly identified. 

 All notes have undergone careful consideration and if the least doubt has existed 

 as to their authenticity, they have been stricken out. Thus certain recently re- 

 corded breeding notes have not been admitted on account of a doubt as to the 

 identity of the species in question, although I could not prove it to thave been 

 wrong. 



All species and subspecies, concerning the relationship of which there was 

 any uncertainty, have been carefully looked up or submitted to the best authori- 

 ties for verification. In case of slight races, comparative series have been exam- 

 ined, and their status as accurately as possible determined. 



The present list, with the accompanying notes, is the result mainly of ob- 

 servations made by members of the Southern Division of the Cooper Ornitholog- 

 ical Club, and cover little more than the past six or eight years, a very short time 

 as compared with the years of careful observation carried on in some of the East- 

 ern states. Yet the results of our work are so favorable that it is hoped we are 

 not judged conceited or hasty in publishing at least this annotated list. 



The region dealt with may seem to be rather iil-defined, but I think that, as 

 restricted, it comprises a neat little geographical area, quite distinct from the sur- 

 rounding country. It is very seldom that faunal areas coincide with political di- 

 visions, and frequently a state or county may lie in parts of two or more entirely 

 different regions, as in the case of Los Angeles County, which is about half and 

 half in the desert and in the Pacific district. 



As indicated by the title of this paper, the region here dealt with is the por- 

 tion of Los Angeles County lying southwest of the divide between the desert and 

 the Pacific slopes. The lower part of Orange County lying west of the Santa Ana 

 mountains is also included, as it is topographically identical with the contiguous 

 portion of Los Angeles County. 



The region under consideration presents considerable variation as regards to- 

 pographic characters, and to this fact may be attributed the large number of 

 birds found in so limited an area. It is approximately sixty miles square in extrem^ 

 dimensions. Beginning at the seacoast, there is a gradual rise to the base of the 

 main mountain ranges when there is an abrupt elevation to the divide, which va- 

 ries from 4000 to 9000 feet in altitude. Along the coast there are several bayous 

 with extensive salt marshes. A litle further inland, in the artesian well districts 



