LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 143 



pattering occasionally on the water with their feet and pick up the 

 smaller pieces in their bills or peck at the larger fragments. Their 

 natural food includes shrimps and other small crustaceans, floating 

 mollusks, perhaps small fishes occasionally, and probably many other 

 forms of minute marine animals which are found swimming on the 

 surface or in floating masses of seaweed. 



Behavior. — The flight of the Leach petrel is swift, graceful, and 

 strong, but not sufficiently distinctive to identify it with certainty. 

 It can, however, be distinguished from the Wilson petrel, the other 

 common petrel off our Atlantic coast, by its larger size and relatively 

 shorter legs which are entirely hidden by the tail in flight, while the 

 long legs of the Wilson petrel project conspicuously beyond the tail ; 

 the tail of the Leach petrel is markedly forked while that of the 

 Wilson petrel is square. Mr. Walter H. Rich, who has studied these 

 birds on the fishing banks, found them — 



Instantly recognizable from the marked differences of wing action ; the Wil- 

 son, with its apparently shorter, wider, and rather leaf-shaped wing and rapid 

 fluttery, constant, mothlike flight, is unmistakable when contrasted with the 

 slower, more irregular stroke of Leach petrel. The smaller species at once 

 suggested to me the chimney-swift, while the fork-tailed species, with its ap- 

 parently much longer wing, modeled after the pattern of that of the shorebirds 

 and plied in much the same manner, recalled in its erratic flight and somewhat 

 spasmodic wing action, a nighthawk gleaning its evening meal above the tree- 

 tops. Another flight difference noted was the carriage of the wings when 

 " scaling." The small petrel's wings were held flat and a trifle above horizontal, 

 the tips slightly bent upward ; while the fork-tailed species carried the wings 

 down-bent, after the fashion of a shorebird when " sliding up " to the decoys. 



The Leach petrel can not rise easily from the ground, as anyone who 

 has spent a night on their breeding grounds can testify ; here it flops 

 along over the ground stumbling against everything in its way, hali 

 running and half flying ; its legs are too weak to enable it to spring 

 into the air and its long wings need more room in which to work 

 to advantage; but when once under way its flight is full of grace 

 and power. . It swims easily and well, but it apparently never dives, 

 though it frequently dips its head below the surface when feeding. 

 Its reputed power of walking on the water is, of course, a myth ; 

 I doubt if its name was derived from its fancied resemblance to Saint 

 Peter in this respect ; it seems more likely to have been derived from 

 a repetition of its notes. 



Its various notes have been differently described by several writers. 

 Audubon (1840) says that "they resemble the syllables peur-wit, 

 peur-toit." Mr. Rich writes me that the only note or call which he 

 could "trace to this species was a twittering chuckle of perhaps a 

 heavier and more guttural quality than that of the Wilson petrel." 

 Dr. Frank M. Chapman (1912) refers to the note heard on Bird Rock 

 at night as " a distinctly enunciated call of eight notes with a certain 



