Auk 



2 2 Mackav, Habits of the Double-crested Cormorant. T^ 



previous to my visit, they were most vigilant, being noticeably 

 careful in looking the rock well over and flying around it before 

 coming within shooting distance. Those birds which were only 

 wounded disgorged soon after striking the water, and I saw a 

 Herring Gull {Lams argcntatus smithsonianus) pick up and 

 swallow an eel one of them had ejected after being shot down. 

 All the Double-crested Cormorants (P. dilophus) obtained had 

 eels (Augu/lla 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 instance 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. I am puzzled to know just where or how so 

 many eels could have been obtained so early in the season. It is 

 possible the birds may have discovered some spring hole near the 

 mouth of some creek or river which, being warmer than the sur- 

 rounding water, gave to the eels a vitality which they otherwise 

 would not have had so early in the season ; and the Cormorants 

 having made such discovery, used it to their advantage. If so, I 

 infer the birds must have performed the greater part of their 

 fishing somewhere up the Seconnet River. 



When approaching the rock the birds usually fly about and 

 often completely encircle it before alighting. I also noticed that 

 they were very apt to first alight in the water near at hand where 

 they remained for a little while, especially if the weather was 

 moderate, before flying up to roost on the rocks. This I have 

 seen them do repeatedly. At the date of my visit (April 19, 

 1S92) I should estimate the number of Cormorants frequenting 

 these rocks, and which were apparently all Double-crested (P. 

 delophus) at about one hundred and fifty. Between half past 

 five to six P. M. on April 19, 1S92, I counted sixty in one flock, 



