118 How to Sex Cage Birds. 



Owing to the fact that the Conurince exhibit no constant feature 

 characteristic of sex, but each species has to be separately studied, 

 it was not worth while to illustrate the sexual differences in any 

 one species as a general guide to the student ; it is enough to point 

 out what differences exist in each species as evidence that in none 

 of them is there any difficulty in discovering whether one has both 

 sexes by carefully comparing the outline of the beaks from above 

 and in profile. 



Chapter XXIII. 



AMAZONS, ETC. (Pionince). 



I believe it is a general rule in the case of the Amazons for the 

 eyes of the males to be darker than those of the females, but it is 

 possible that in both sexes they may deepen somewhat with age, 

 which would account for slight discrepancies which occur in 

 descriptions of the same species, or such vague indications as one 

 finds in some of Dr Runs' descriptions — "yellow to orange-red," 

 though more probably in this case the '"yellow" represents the iris 

 of the female, the " orange-red " that of the male. 



Count Sal vadori usually speaks of the females as "like the male"; 

 sometimes he adds, "perhaps a little duller," and in one or two 

 instances he mentions a difference, but is uncertain whether it 

 characterises a female or a young bird ; all this is disconcerting. 

 On the other hand, the late Mr Abrahams unhesitatingly pronounced 

 my Yellow-fronted Amazon a female, judging by the colour of its 

 eyes, and dissection after death proved the correctness of his 

 decision. 



An examination of the numerous specimens of Amazons in the 

 National Collection shows that (as in the preceding groups) the 

 outline of the beak, although differing a good deal in the opposite 

 sexes, does not always differ in the same manner, but is modified 

 presumably by the habits of each species; thus it is reasonable 

 to suppose that if the male is more energetic than the female in 

 excavating or enlarging the nesting-cavity, his beak will be con- 

 structed especially with an eye to strength, and will be broad, short, 

 but with a strong, sharp, but curved terminal tooth ; if, on the 

 other hand, his energies are directed to defence rather than con- 

 struction, a longer beak, with a nearly straight conical stabbing 

 hook, is likely to be more serviceable; when the female chiefly prepares 

 the nesting-cavity or is active in defending her nest, she naturally 

 requires the same tools or weapons, and thus it comes about that 

 in a few species the rostral features of the sexes appear to be 

 reversed ; generally, however, the longer beak is characteristic of 

 the males. 



