2 CALIFORNIA ACADEMY OF SCIENCES. 



were no penetrating fogs. With green grass, flowers 

 blooming in every yard, strawberries on the vine, it was 

 difficult to realize it was winter, although the higher 

 mountains in the distance were whitened with snow. 



The surprises that await the student of birds invading 

 an unworked field were not wanting in the present instance. 

 Some species that were confidently expected were not 

 found and others that were not even thought of as winter 

 birds proved to be more or less common. It was fully 

 anticipated after the experiences of August that the three 

 Jaegers and Sabine's Gull would occur as winter residents, 

 but not a single individual of any one of these species 

 was seen. It is scarcely to be supposed that the tide of 

 their migration passed wholly by Monterey, or, on the 

 other hand, that it had receded northward. Doubtless 

 the locality was within the winter range of some of them 

 at least, the local centers of distribution being to the 

 northward and southward. 



MIGRATION. 



A greater surprise than the absence of the boreal birds 

 mentioned was the presence of the Black-vented* and the 

 Dark-bodied Shearwaters. Thousands of the former 

 passed Monterey Bay on their way southward. Winter 

 migration in birds nesting in the Northern Hemisphere is 

 a well-known fact, there being continual movement south- 

 ward and northward as the zone of snow and ice advances 

 and retreats, but migration southward in the Northern 

 Hemisphere in winter to breeding grounds appears to have 

 escaped the observation of ornithologists. Such a migra- 

 tion exists in the Black-vented Shearwater. 



During two hours of the latter part of the forenoon of 

 December 14th fully two thousand Black-vented Shear- 



* This name, Black-vented Shearwater, is adopted provisionally in the 

 remarks that follow. See 'General Observations ' beyond. 



