Chap. XVI.] THE YOUNG LIKE THE ADULT MALES. 197 



incubation. With the carrion-hawk of the Falkland Isl- 

 ands (31ilvago leucurus) I was much surprised to find by 

 dissection that the individuals, which had all their tints 

 strongly pronounced, with the cere and legs orange-col- 

 ored, were the adult females; while those with duller 

 plumage and gray legs were the males or the young. In 

 an Australian tree-creeper ( Climacteris erythrops) the fe- 

 male differs from the male in " being adorned with beauti- 

 ful, radiated, rufous markings on the throat, the male hav- 

 ing this part quite plain." Lastly, in an Australian night- 

 jar " the female always exceeds the male in size and in 

 the brilliance of her tints ; the males, on the other hand, 

 have two white spots on the primaries more conspicuous 

 than in the female." 26 



We thus see that the cases in which female birds are 

 more conspicuously colored than the males, with the 

 young in their immature plumage resembling the adult 

 males instead of the adult females, as in the previous class, 

 are not numerous, though they are distributed in various 

 Orders. The amount of difference, also, between the sexes 

 is incomparably less than that which frequently occurs in 



23 For the Milvago, see 'Zoology of the Voyage of the Beagle,' 

 Birds, 1841, p. 16. For the Climacteris and night-jar (Eurostopodus), 

 see Gould's ' Hand-book of the Birds of Australia,' vol. i. pp. 602, 97. 

 The New Zealand shieldrake (Tadorna variegata) offers a quite anomalous 

 case : the head of the female is pure white, and her back is redder than 

 that of the male ; the head of the male is of a rich dark bronzed color, 

 and his back is clothed with finely-pencilled slate-colored feathers, so 

 that he may altogether be considered as the more beautiful of the two. 

 He is larger and more pugnacious than the female, and does not sit on 

 the eggs. So that in all these respects this species comes under our first 

 class of cases; but Mr. Sclater ('Proc. Zool. Soc' 1866, p. 150) was 

 much surprised to observe that the young of both sexes, when about 

 three months old, resembled in their dark heads and necks the adult 

 males, instead of the adult females ; so that it would appear in this case 

 that the females have been modified, while the males and the young have 

 retained a former state of plumage. 



