2 6 J. Mackay, Terns of Muskeget and Penikese Islands. \j% 



The birds were breeding this season most abundantly at the 

 east and west ends of the island. While walking over the island 

 on July i, Mr. Sandsbury saw a Wilson Tern suddenly fall nearly 

 at his feet from the air. On examining the bird, which was 

 apparently nearly dead, he could find nothing out of the way ; 

 smoothing its feathers, he laid it on its breast on the sand, and 

 placing an upright stick beside it, that he might find it on his 

 return, he left it. It was not there on his return, and as no one 

 had been in view meanwhile, he supposes the bird recovered and 

 flew away. 



Soon after my visit I learned from Mr. S., and later from 

 others, that quite a number of Wilson Terns had been found 

 dead on this island, with no apparent injury externally, their 

 plumage being unruffled. Mr. S. estimated the number he had 

 seen at thirty. None were observed on any of the other islands. 

 No Roseate Terns were noted among these dead birds, although 

 Mr. S. looked for them. They were apparently all Wilson Terns 

 (S. hirundd) , with the exception of two birds, which he described 

 as having very dark breast feathers. It is probable that these 

 were Arctic Terns {S. paradisaa) , as he found them in the 

 locality most frequented by them. It has been rather rare in my 

 experience to find dead adult Terns lying about on any of the 

 islands. I cannot recall over two or three in half a dozen years. 

 I have no facts to offer in explanation. A good many young 

 Terns just about to fly, were also fonnd dead by Mr. S. this 

 season, but on consulting with him later we concluded that the 

 mortality was only normal. 



I noticed fewer Arctic Terns this season than formerly, but I 

 am not sure that their former numbers have decreased. I saw 

 two or three on Muskeget proper, near the middle of the island, 

 on July 3, one of which was particularly aggressive. 



Of the eggs discovered this season all were normal with the 

 exception of one clutch of two Roseate ? eggs taken on July 4. 

 The ground color of one of these was white, with the faintest 

 tinge of green, with fine pen-point brown dots sparsely distributed 

 over the whole egg, increasing in density, but only occasionally 

 in size, towards the larger end of the egg ; the other egg was of 

 similar size and normally dark colored. 



