174 Saunders, Recording Bird Songs. [April 



birds sing in any given key? Do they recognize any fundamental 

 notes? Can one beat time to a bird's song? In the majority of 

 cases these questions must be answered in the negative. Only a 

 few individuals of certain species approach these standards of 

 music. The great majority of birds sing in a free, non-mechanical, 

 natural manner that cannot be recorded on the musical scale 

 with the exactness that it deserves. If we have no better method 

 we must resort to musical notation, but if we can find a better 

 method, one which discards the mechanical rules of human music, 

 without losing any of its scientific accuracy, we can take a long step 

 in advance toward the true scientific study of bird song. 



Before discussing the possibilities of such a method, it is first 

 essential to have a definite classification of the points concerning 

 which we desire information to make our knowledge of a given song 

 complete. These points appear to me to be five in number. They 

 are pitch, duration, intensity, pronunciation and quality. Con- 

 cerning quality I have no suggestions to offer farther than those 

 already made by others. Sound qualities are baffling and difficult 

 to describe with accuracy, and, until we can have a definite and 

 practical classification of, them, they will continue to be so. 



Our records of pitch, duration and intensity must be first com- 

 parative, for the different notes or parts of a given song, and second 

 absolute, for a comparison of the song with other songs of the same 

 or another species. A pitch pipe, together with a good musical 

 ear, are necessary to obtain the comparative and absolute pitch 

 in the field. A stop watch is probably the best instrument with 

 which to get records of duration. Comparative intensity can be 

 recorded with reasonable accuracy by ear, but absolute intensity 

 is more difficult to measure. The intensity of a song must neces- 

 sarily vary with the weather conditions, the temperature, the 

 pressure of the air, and above all the direction and velocity of the 

 wind. We know, however, that the intensity of sound varies 

 inversely as the square of the distance from its source, and this 

 gives us something tangible to go by. If then, our bird will remain 

 in one spot singing, on a day when there is no wind, while we find 

 the farthest point at which the softest and loudest parts of its song 

 are audible, we will have a definite measure of intensity. This 

 process seems destined to try to the utmost the patience and 

 perseverance of the future student of bird song. 



