OBSERVATIONS ON BIRDS. 



NOTES OF BIRDS. 



BIRDS which are silent during the winter, as most 

 are, appear to acquire their notes in the spring by 

 degrees. At first their song is very weak and imper- 

 fect; and to hear them labouring at it, and only 

 managing to get a part out, conveys the idea of 

 some physical impediment, which for a while they 

 are unable to surmount. As the temperature of the 

 season advances, their system receives a correspond- 

 ing stimulus, and their song becomes louder and 

 more lengthened.* This may be particularly noticed 

 in the chaffinch, and those birds whose song is 

 generally made up of a definite number of notes. I 

 have also observed it in the ring-dove, whose cooing 

 note with us, in the height of the summer, is 

 invariably repeated five times to complete the usual 

 call ; but in January and February, when these birds 

 are only induced perhaps by a mild day just to try 



* There is some allusion to this circumstance in White's Sel- 

 borne. See his Fifth letter to D. Barrington, where I have pre- 

 viously given the substance of the above remark in a note, in my 

 edition of that work. 



