224 Mackay, Notes on Certain Water Birds. [ July 



waters between Woods Holl and Naushon Island, Mass. On 

 March 13, 1894, during a strong southwest wind, they all 

 departed and were not observed afterwards. Mr. Edwards had 

 saved the contents of the stomachs of some Eiders which were 

 shot on February 11 and 15, which I saw; they consisted of 

 sculpin spawn, in perfect condition, in small masses stuck 

 together, and black mussels {Modiola modiolus) ground up to 

 the consistency of fine sand and black in color. Four female 

 King Eiders (S. spectabilis) were taken there on February 20, 

 1S94, and the contents of the stomachs saved, which I also saw, 

 consisted entirely of Tritca trivittata in good quantity and 

 condition. 



Such a very large collection of Eiders, in so restricted a 

 locality as the one above mentioned, can only be explained by 

 the great abundance of the black mussel which these birds first 

 discovered in the winter of 1892-93. These beds of mussels had 

 increased to such an enormous extent that some of them, which 

 were attached one to another, are said to be five feet or more in 

 thickness. Only such masses are able to survive under the 

 peculiar conditions which exist there, due to the great pressure 

 of water which rushes with great force through this narrow 

 passage or strait, connecting Buzzards Bay with Vineyard Sound. 

 When the birds were disturbed by the steamboats which passed 

 daily they would fly out into the Sound, where they would 

 remain awhile, returning later. Although considerably harassed, 

 and many shot, it apparently produced little effect on them, for 

 they refused to forsake so attractive a feeding ground, and con- 

 tinued to frequent it. I have little doubt that they will again 

 appear in the same large numbers if the food supply continues in 

 this locality next season. 



No Brant (Branta bernicla) wintered around Muskeget Island 

 during the winter of 1S93-94. The first that were noted were 

 five birds on February 15, 1S94. In less than one week the 

 number increased to fifty, and on March 12 there were between 

 four and five hundred, the larger half of which had come in 

 since March S. I noticed considerable diminution in the food 

 supply, many acres of the eel grass (Zostera marina) having 

 been killed. There was still remaining large areas that was 

 good . 



