LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 243 



records, April 28 to May 19. Greenland: April 28 to July 25 

 (Hageriip). 



PHALACROCORAX AURITUS AURITUS (Lesson). 

 DOTJBLE-CRESTED CORMORANT. 



HABITS. 



Among the passing flocks of wild fowl which migrate along the 

 New England coast, one occasionally sees a flock of large black birds 

 flying high in the air in a regular V-shaped formation like geese, or 

 in single file, or rarely in an irregular bunch. At first he may mis- 

 take them for geese or brant on account of their size and manner of 

 flight, which is heavy and strong, with rather slow wing strokes, but 

 if he watches them carefully he will see them set their wings and scale 

 along at occasional intervals, by which he recognizes them at once 

 as cormorants or " shags." There are two species of " shags " found 

 on this coast, the double-crested and the common cormorant, of 

 which the former is much the commoner. 



Courtship. — On the flat top of Peroe Rock, which stands only a 

 few rods from the shore of Perce, Quebec, is a large breeding colony 

 of double-crested cormorants and herring gulls, and the top of the 

 rock is about level with the heights of Cape Cannon, the nearest 

 point. On June 19, 1920, while watching this colony from that 

 point through a powerful telescope, I had a good opportunity to 

 study thfe courtship or nuptial greeting of this species. Many 

 birds were standing hj their mates on the nests; others were con- 

 stantly coming or going. The incoming bird, presumably the male, 

 bows to his mate and walks around her with his neck upstretched 

 and swollen, opening and closing his bill. Then approaching his 

 mate he begins caressing her with his bill; she steps off the nest; 

 then both begin a series of snakelike movements of heads and necks, 

 almost intertwining them. Finally he passes his head over, under, 

 and around his mate, apparently caressing her from head to tail, 

 and he or she settles down on the nest. 



Nesting. — Many of the birds must reach their breeding grounds on 

 the south coast of Labrador by the middle of May or earlier, for we 

 found their nesting operations well under way during the last week 

 in May, and they are said to begin nest building before the snows of 

 winter have passed away. They must be very common all along this 

 coast, for in a T5-mile cruise from Esquimaux Point to Natashquan, 

 Doctor Townsend and I saw three breeding colonies in 1909. These 

 were all on low, bare, rocky islets well off the coast. The first colony 

 visited, on May 26, was on Seal Rock, off St. Genevieve Island, a low- 

 lying rock of less than an acre in area. From a distance we could 

 see the large black birds sitting all over it, but as we approached it in 



