The Umbrella-bird 107 



differs from the others in having the whole of the throat 

 naked and of a red colour, as well as the caruncle which 

 proceeds from the throat. In the Amazonian Umbrella- 

 bird and its ally from Western Ecuador, this long caruncle 

 is densely feathered, and forms a kind of dew-lap. The 

 " Umbrella " consists of a sort of hood formed by the 

 feathers of the forehead and crown, which are long, and 

 curve over at the ends. All the species have a peculiar 

 and far-sounding cry, and are all inhabitants of forest- 

 country, from the depths of which their note resounds. 

 When uttering this note, the bird spreads its crest, waves 

 its pendent neck-lappet, and bows its head as it pipes. 

 There is not so much difference in the colour of the sexes 

 in the genus Cephalopterus, the female being only slightly 

 duller in colour, and having the crest and dew-lap much 

 less developed. 



In certain forms of birds, however, we find that the sexes 

 are alike in colour of plumage, and even in decoration. 

 One of the most striking examples of this phenomenon, 

 which is extremely rare in the Class Aves, is exhibited 

 by the Grebes (Podicipedidce). Even in our familiar little 

 Dabchick {Podicipes fluviatilis) y both male and female put 

 on the same plumage in summer, and from the silvery 

 breast and brown upper surface of the winter dress, they 

 become black above and below in- summer, and show a 

 considerable amount of chestnut on the sides of the head 

 and neck. The young of the Grebes are also peculiar, and 

 are streaked with black and white like little Zebras. One 

 of the most curious instances of assimilation in ornamental 

 decoration of the sexes of a bird is exhibited by the Great 

 Crested Grebe (Podicipes cristatus). Here the two birds 

 are coloured alike, the tippet assumed during the breeding 

 season being donned by both male and female, so that 

 there is practically no difference in colour between the 

 sexes, except that the head-dress of the female is not quite 



