76 



Correspondence. ^ 



LJan. 



of 1896. "I devoted much time in trying to shoot them" he says (on 

 page 3S8) ; and in a footnote : " All but one were shot before the close of 

 the season." 



All'friends of bird protection must recognize with gratitude the work 

 done by Mr. Mackay and his associates in protecting the colonies of 

 Terns and Laughing Gulls on Muskeget — work which can scarcely be 

 appreciated by one who has not seen the teeming life which in summer 

 now covers the barren sand hills of the island. But when bird protection 

 results in the destruction of a family of Owls, which, notwithstanding its 

 numerical insignificance, far outweighs in biological interest the largest 

 Tern colony on the entire Atlantic coast, it is necessary to enter a protest. 



The vertebrate fauna of Muskeget may be roughly divided into two 

 groups: 1st, animals which there find conditions essentially normal and 

 similar to those to which they are subjected throughout their range; 

 and 2nd, animals which there find essentially abnormal conditions, that 

 is, conditions which distinctlj' differ from those to which they are else- 

 where exposed.' To the first class belong most of the breeding birds, 

 among which may be mentioned : Sterna hirtittdo, S. dougalli, S. para- 

 discea. Lams atricilla, ^^gialitis nieloda, Actitis niacularia, Agelaiiis 

 ph<eniceiis, Stur?ieUa magna, Ammodramus catcdacutus, A. sand%vlcke?ists 

 savanna, and Melospiza fasciata!^ The coast form of the common toad 

 probably belongs also in this category. In the second class we find the 

 two mammals of the island, a Vole and White-footed Mouse, and only one 

 bird, the Short-eared Owl. It is to the members of the second class that 

 the chief interest attaches, because they are rapidly undergoing modifica- 

 tion to fit them to the needs of their peculiar environment, while no such 

 process is taking place among the inhabitants of the island that find 

 there their normal surroundings. The process of change has progressed 

 furthest with the Vole, Microtus bre%veri (Baird), which is now so 

 much differentiated as to be readily separable from the wide-ranging 

 Microtus pennyslvanicus of Nantucket, Martha's Vineyard and the 

 adjacent mainland. The White-footed Mouse, Peromysctis leucopus 

 (Rafinesque), is beginning to undergo a series of changes which if not 

 interruped will doubtless eventually result in the formation of a new 

 species.''^ A similar process would doubtless take place in the Owls if 

 they were strictly protected and allowed to become firmly established on 

 the island, for the bare glaring sand and scant vegetation among which 



* A similar classification could probably be made with the plants, but here 

 the preponderance of the first class would be even greater than in the case of 

 the land Vertebrates. 



^ This list is taken from a summary of the Muskeget fauna published in 

 1896. Miller, Proc. Host. Soc. Nat. Hist., XXVII, pp. 79-83- 



3 See Miller, Proc. Bost. Soc. Nat. Hist., XXVII, p. 80. 



