248 BULLETIN 121, UNITED STATES NATIONAL MUSEUM. 



rormal time at which the first postnuptial molt takes place. This 

 molt is complete, though much prolonged, and produces the second 

 winter plumage, which is similar to that of the adult when complete. 

 It is often not completed, however, until the latter part of the winter, 

 when the bird may be said to be in its second nuptial plumage. This 

 is similar to the adult nuptial plumage except that the crests are 

 lacking on the sides of the head. Up to this time the young bird has 

 been undergoing an almost constant change and development of 

 plumage and it is now ready to breed. 



The plumage changes of the adults are simple; a complete post- 

 nuptial molt in the late summer produces the winter plumage and a 

 partial prenuptial molt early in the spring produces the nuptial 

 plumes on the sides of the head which are characteristic of the mating 

 season and constitute the only marked difference between the nuptial 

 and the fall or winter plumages. These nuptial plumes are appar- 

 ently shed during the nesting period, as they are seldom seen after 

 the season is well advanced. 



Food. — The food of the double-crested cormorant consists almost 

 entirely of fish, which it obtains by diving from the surface or swim- 

 ming below it, at which it is an adept, capable of making great speed 

 under water, diving to great depths and remaining under for a long 

 time. I have seen it stated that cormorants use their wings in flying 

 under water, but I doubt if they do so regularly ; their long slender 

 bodies and powerful totipalmate feet are highly specialized for rapid 

 swimming, without the aid of wings. On the New England coast 

 they are frequently seen flying up the larger rivers and tidal estuaries 

 to fish, where they live largely on eels. Mr. George H. Mackay 

 (1894) makes the following interesting statement regarding the food 

 of this species in Rhode Island : 



All the double-crested cormorants (P. dilophm) obtained had eels (Anguilla 

 vulgaris Turton) in their throats. In four of the birds the heads of the 

 eels had been apparently torn off and they rested in the throat in every in- 

 stance in the form of a loop or ox bow, the two ends being nearest the stomach. 

 In the fifth and largest bird an eel in perfect condition, measuring sixteen 

 inches long and one inch in diameter, rested lengthwise in the throat with 

 the tail at the mouth. Those taken from the other four birds were seven to 

 ten inches long. It would therefore seem that eels constitute a large part of 

 their- food in this locality, at least at this time. I also picked up on the top 

 of the rock an eel in a partially dried condition, minus its head, which was 

 probably seven or eight inches long before the head had been torn off. It was 

 in the form of an ox bow or loop, having dried as it was probably ejected. 



He also speaks in the same paper of finding their ejected pellets 

 of fish bones on a rock off Seaconnet Point, Rhode Island : 



On the flat top of the rock I found and saw a large number of curious balls 

 (and brought fourteen away with me) varying from an inch to two inches in di- 

 ameter and composed almost entirely of fish bones, chiefly the bones of young 

 parrot-fishes (Labroids) and drums (Sciaenoids) firmly cemented together 



i\ 



