2IO CALIFORNIA ACADEMY OF SCIENCES. 



comparatively small. The vast region above this line, 

 abounding in summer with the means of supporting bird 

 life, must be largely depopulated before winter. Hence 

 there is southward migration of birds — migration that ex- 

 tends eVen into a land of summer in the Southern Hem- 

 isphere. Winter also enforces depopulation of Arctic 

 seas. In the lapse of time sea birds like the California 

 Murre have seemingly learned, after the cares of repro- 

 duction are over, to move further south in the sparsely 

 populated region of great food store, making room for 

 the countless hosts that must leave the region of their 

 birth before the chilling breath of winter has turned it 

 into a region of desolation and famine.* 



GENERAL REMARKS ON THE BIRDS OBSERVED. 



Only species of which specimens were taken are men- 

 tioned in the notes that follow. When no year is given, 

 1894 is to be understood. The determinations are based 

 in most instances upon printed descriptions and are there- 

 fore in a measure provisional. 



.^chmophorus occidentalis. Western Grebe. — To- 

 ward the end of summer this Grebe became tolerably 

 common. A male, taken July 2d, was the first individual 

 of the season met with. 



Colymbus nigricollis californicus. American Eared 

 Grebe. — An adult female was captured on the bay July 

 i6th. This was the only example of this species observed 

 during the summer. 



Podilymbus podiceps. Pied-billed Grebe. — A single 

 specimen that was found dead upon the water near the 

 Seaside Laboratory, August nth, was the only one seen. 



*As tliere is early southward migration in temperate climates in breed- 

 ing representatives of "resident" land birds, it. is not surprising that an 

 apparently similar migration exists in "resident" sea birds. In this con- 

 nection, see "Auk," vol. ix, pp. 33-39; xi, pp. 100, 101, 103, 104, 108, 109. 



