138 MATESHIP WITH BIRDS 



than their melodious calls, whistles, chatter, or 

 songs. In this regard I think particularly of cer- 

 tain members of the genus Pachycephala, generally 

 known as "Whistlers." 



Australia would be a good deal poorer ornitholo- 

 gically without many of the seventeen or eighteen 

 species which constitute the Commonwealth's repre- 

 sentation of this, a large group "peculiar to Aus- 

 tralia and adjacent islands to the northward." I 

 use the word many for the reason that at least half 

 of our full number of Whistlers are confined to the 

 far north of the continent, and are unknown save 

 to the pioneering ornithologist, who, gun in hand, 

 will brave the dangers of the mangrove swamps 

 and other waste places on the chance of discovering 

 a "new" bird. 



But there are others of the family which take 

 rank among the common birds of Australia, and 

 which would be even better known if they had 

 better names. As with several other Australian 

 birds, their vernacular title is distressingly in- 

 definite in a country "where the very air is ring- 

 ing" with the melodious whistling of full many 

 birds. This much may be conceded, however: 

 "Whistler" is infinitely to be preferred to the old 

 term of "Thickhead," which some ungracious scien- 

 tist, not satiated with the generic title (Pachus, 

 thick; kephale, the head), early bestowed upon the 

 birds because, forsooth, dissection showed them to 

 be comparatively broader across the cranium than 

 most other families ! 



Theories on the point of sexual selection and pro- 

 tective coloration become somewhat involved in con- 



