I^O BiCKNELL Oil the Singing of Birds. [April 



silent in the autumn. It is, however, probable that singing may 

 occasionally be indulged in that season, for I was assured by one 

 w^ho was familiar with the song of the species, that several were 

 heard singing at Bay Ridge, Long Island, September 26, 18S0, at 

 the height of their migration. 



On their arrival in September the new plumage has not always, 

 completed its growth. In many specimens growing feathers are 

 scattered over the body, and often some of the remiges have their 

 bases still soft, or even sheathed by the matrix of the feather. 

 When the birds first appear they have begun to develop adipose 

 tissue, and it is not long before they become excessively fat. 



Turdus aliciae. Gray-cheeked Thrush. 



To this species almost the same remarks apply as to the last- 

 mentioned, except that it appears disposed to tarry a little longer 

 in the spring ; consequently its song may sometimes be heard a 

 few days later. It is occasionally in song with us through the 

 first week of June, — that is, I have heard it up to June 4. 



I am well satisfied that the songs of the- Gray-cheeked and 

 Olive-backed Thrushes are not alike ; in fact that they are as dis- 

 tinct from one another as from the songs of the other small 

 Thrushes. 



During recent seasons particular attention was paid to the 

 songs of these birds, and a clear difference betv^^een the songs of 

 individuals of each proved to be constant, so far as limited 

 observation went. As a result of m}' experience with these 

 birds, I have little hesitation in characterizing the song of 

 the Gray-cheeked Thrush as weaker than that of the Olive- 

 backed, entirely dissimilar in tone, and with a somewhat dif- 

 ferent disposition of the notes. Instead of musically outbursting, 

 it is singularly subdued, and has a far-away and rather ven- 

 triloquial sound. It seems m.ore the expression of some dis- 

 tant emotion revived in memory than of a suddenly felt present 

 emotion which the song of the Olive-backed Thrush suggests. 



The song of the latter bird is louder, more spontaneous and 

 lyrical. Almost the first note is the loudest and most liquid, after 

 which the melody becomes rapidly fainter, seeming to dissolve 

 upon the air like the spent vibrations of a stringed instrument. 



