l8o CALIFORNIA ACADEMY OF SCIENCES. 



Una I tried the experiment, during the height of migra- 

 tion, of sending aut each morning an assistant I had 

 trained, to collect birds in a direction opposite from the 

 one I would take myself. The results of our day's shoot- 

 ing were often very different — so different were they 

 that I have since been fully convinced that a single ob- 

 server, diligently spending each day in the field, can know 

 but little of the rarer birds that happen to be in his neigh- 

 borhood at the time of his observations, and how impos- 

 sible it is for a single observer ever to exhaust a locality, 

 even one of but a few square miles in extent. 



The incipient stages of southward migration of the 

 species that breed in a locality are not always very ap- 

 parent. Daily records intelligently kept afford a key, 

 however, to these indefinite movements, for they gradu- 

 ally develop into those that are unmistakable. The im- 

 mediate vicinity of Monterey is an advantageous situation 

 for the study of such migration in sea birds, for there are 

 no suitable places for rookeries, which causes the south- 

 ward movements of individuals of breeding species of the 

 region, from rookeries further up the coast, to be like the 

 movements of species that rear their young only in the 

 high north. At the rookeries, migratory movements may 

 not always be apparent at the outset, for departure from 

 them after reproduction is over may be simply forsaking 

 of the land for the water, the real home of sea birds. 



yune. — On June i6th, California Murres were moving 

 down the coast. A number of individual birds, a few 

 couples, and one small company, were seen flying south- 

 ward, following the shore-line. This was apparently a 

 migratory movement, for in the weeks that followed these 

 Murres continued to pass south in increasing numbers, 

 with no returti movements. While no breeding places of 

 this species were actually discovered, my observations 



