I ^ 4. Turner on Birds of the Nearer Islands. Alaska. [April 



muscular acts which, in many birds, are synchronous with the 

 utterance of certain notes, may thus be motions which are nec- 

 essary to the special operation of the air-sacs. 



And if this be true it affords an explanation of the fact that 

 the song of many birds is often more varied and prolonged in 

 flight than when they are at rest, and that the highest vocal 

 expression of some birds, as the Oven-bird, the Maryland 

 Yellow-throat, and the Yellow-breasted Chat, for examples, is 

 achieved only when the birds are on the wing. 



The surprising length of time for which singing is often sus- 

 tained argues greater resources of air supply than the mere 

 capacity of the lungs, and here again we may have recourse to 

 a special operation of the pneumatic system. 



We have already seen that birds in general are most voiceful 

 when having least fat; if the growth of fat on the body reduces 

 the capacity of any of the air-sacs a reason for this is evident. 



( To be continued^) 



NOTES ON THE BIRDS OF THE NEARER 

 ISLANDS, ALASKA. 



BY LUCIEN M. TURNER. 



The localities here included embrace the islands of Attoo, 

 Agattoo, and Semechi, with their outlying islets. The geo- 

 graphical position of the group lies between 185 30' and 1S7 30' 

 W. of Greenwich. The parallel of 52 N. passes near their 

 center. The group forms the westernmost portion of the Aleu- 

 tian chain of islands, and, taken collectively, is known as the 

 Bleezhnee or Nearer Islands, being so designated by the earlier 

 explorers because they lie nearest to the Asiatic coast. 



Semechi is the smallest of the three, and lies about twenty-three 

 miles to the southeast of Attoo. It is quite low on the southern 

 side, where are found innumerable ponds and lakes, some of the 

 latter being of considerable area. The low-grounds are covered 

 with vegetation of various kinds, and the shallower ponds, in some 

 instances, yield vegetable food in abundance for the great numbers 



