COURTSHIP AND SEX 195 



§ 9. The Interpretation of Song 



There are two extremes in the interpretation of the song 

 of birds. The first is too materiaHstic ; it leaves the mind 

 of the bird out altogether. The second is too generous ; 

 it allows too little for the body, too little, for instance, for 

 the hormones which pass from the reproductive organs of 

 the male and, being distributed through the body by the 

 blood, prompt the full development and activity of certain 

 parts, such as the syrinx. Similarly in the female there are 

 hormones which inhibit the expression of masculine cha- 

 racteristics, such as song. In " crowing hens " and similar 

 phenomena there is either atrophy of the ovary or some 

 testicular development. 



Amongst songsters the syrinx of the female often shows a 

 grade of evolution — or should one say development ? — 

 distinctly lower than that of the exuberant male ; and this is, 

 of course, associated with the fact that the female may have 

 no song at all, or only a little. The probabiHty is that 

 hormones from the ovary inhibit the development of the 

 female syrinx. 



It has been proved, in a few cases, that a young bird 

 artificially hatched can utter certain sounds characteristic of 

 its kind. The peewit will say " Peewit," or something very 

 like it, the moment it is hatched, and a cry from within the 

 egg is sometimes heard. This points to the instinctive or 

 hereditary nature of the ability to utter certain characteristic 

 notes. There is a counterpart of this in the way in which 

 some young birds, such as partridges, respond instantaneously 

 to the parental alarm note when heard for the ver)^ first time, 

 though they remain indifferent to the more urgent warning 

 of their foster-mother hen. 



But while a certain amount of vocal ability is part of the 

 hereditary make-up, there seems little doubt that the gift 

 requires educating. The song of the first year is sometimes 

 inclined to be tentative and generalised. It improves with 

 practice, and is probably helped by emulation and imitation. 



