35^ CALIFORNIA ACADEMY OF SCIENCES. 



awakened and informed that the bird population was in 

 uproar. It was pitch dark, but the whole island seemed 

 to be alive with birds. Their voices, suggestive of those 

 of Whip-poor-wills, filled the air. I was told this noc- 

 turnal concert was given by Cassin's Auklets. From 

 this incident some real conception was formed of the 

 abundance of this species upon the island. 



Cepphus columba. Pigeon Guillemot. — The sibilant 

 notes of ' Sea Pigeons ' greeted the ear all through the 

 day on the eastern part of the island, where they were 

 very common sitting about on the rocks. West End was 

 apparently not congenial to them, for none were noticed 

 there. Unlike the Tufted Puffins, they were very timid 

 when brooding, taking flight whenever the crevices con- 

 taining the eggs were approached closely. A set of fresh 

 eggs was found the first day near the wharf in Fisher- 

 man's Bay. The laying season, however, appeared to 

 be practically over before my visit. 



Uria troile calif ornica. California Murre. — The 

 more inaccessible cliffs and the outlying islets fairly 

 swarmed with Murres. When the eggers approach the 

 Murres retreat to the sea. At first one and then an- 

 other will go, finally the panic becomes general. Al- 

 though each bird starts independently, before the water 

 is reached a great flock is formed. The eggers have to 

 work rapidly or else the Gulls will get ahead of them 

 and share largely in the booty. Many Murres lay on the 

 ledges in the sides of the caves opening into the sea. 

 When a cave is entered most of the birds immediately 

 seek to escape. Those at sufficient elevation launch into 

 the air, heading directly for the exit, and the intruder has 

 to be on his guard lest some of the stream of frightened 

 birds strike his face. A fewer number crowd together 



