LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 79 



Behavior. — The same writer describes the flight of the allied shear- 

 water, in which it seems to differ from the larger species of Pwfftnus, 

 as follows : 



They congregate In flocks, often of considerable size, and fly in a compact 

 body, generally in a zigzag course, with a very rapid movement of the wings 

 and not far above the water. Their flight is peculiar, too, in this respect, that 

 they appear all to turn at the same moment, like a company of soldiers, showing 

 first the dark plumage of the upper surface and then the white underparts as 

 they simultaneously dip toward the water. 



Their habits are sociable, and flocks may often be seen in the daytime dis- 

 porting themselves in the sea, making short flight just above the surface, and 

 then flopping into the water, splashing and chasing one another in their playful 

 gambols, and when tired of their fun rising in a body and rapidly disappearing 

 from view. 



They seem to scatter at night, for as darkness approached I have noticed 

 numerous single examples, as if the flocks of the daytime were dispersing over 

 the surface of the ocean in quest of their food. They fly low but swiftly, and 

 utter a note resembling the native name by which the bird is called, but some- 

 what prolonged, palca-hcu-a-paka-ha-a. 



Occasionally, perhaps once in several years, they appear in prodigious flocks 

 and seem, to cover the sea for miles around ; but they soon scatter again over 

 " ocean's boundless bosom," and are then not more plentiful than the other 

 petrels. 



DISTRIBUTION. 



Breeding range. — ^The form which belongs on the American list, 

 Puffinus assimilis godmani, breeds in the Azores, the Canary Islands, 

 and the Madeira group. Represented by other allied forms in other 

 parts of the world. Much confusion exists as to the relationships, 

 nomenclature, and distribution of Pufinus assimilis, Pwffm,us obscv>- 

 rus, and their subspecies. 



Range. — North Atlantic Ocean, mainly on the eastern side. Prob- 

 ably south to the Equator. 



CosvmI records. — Accidental off Nova Scotia (Sable Island, Sep- 

 tember 1, 1896). Six records for Great Britain, most if not all of 

 which are for this subspecies. 



Egg dates.— Mdideiva, and Canary Islands : Nineteen records, Jan- 

 uary 2 to July 2 ; 10 records, February 2 to 22. 



PUFFINUS OPISTHOMELAS Coues. 

 BLACK-VENTED SHEAEWAIEB. 



HABITS. 



Although this is one of the most abundant of the shearwaters on 

 the Pacific coast, it is only within recent years that we have learned 

 very much about its habits. Prof. Levei'ett M. Loomis has given us, 

 in his various papers, much information regarding its migratory 

 flights along the California coast, but we are indebted to Mr. A. W. 

 Anthony for practically all we know of its life history. 



