io6 A BOOK OF BIRDS 



ornamented by long plumes from the wings, and a long and grace- 

 fully flowing tail. In olden times the native chiefs, and they alone,, 

 wore these plumes on days of high festival. 



THE TOUCANS 



Like the Hornbills, the Toucans have enormous beaks, and on 

 this account are very commonly mistaken one for another by those 

 who are not experts. As a matter of fact they are by no means 

 closely related. 



There are several different species of Toucans, some of which are 

 sober-coloured enough ; but for the most part they are rather 

 richly coloured, while in size they range from birds rather larger 

 than a large thrush up to 2 feet in length. 



The great beak is really extremely light, being formed of a most 

 delicate filigree-work of bone, ensheathed in a very thin case of 

 brightly coloured horn, which is " serrated " along its cutting edges. 

 They have the curious habit of sleeping with the tail cocked upwards, 

 so as to lie almost fiat upon the back. All are fruit-eaters ; but 

 this diet is varied by insects, and occasionally small birds and 

 mammals. 



One of the largest of all the Toucans is the Toco (Plate XIX. 

 fig. 3). It enjoys a wide distribution in South America, and is met 

 with in large fiocks. 



THE WOODPECKERS 



The Woodpeckers are an extremely interesting group of birds^ 

 and this because they illustrate, in a remarkable degree, what is 

 meant by '' adaptation to environment." That is to say, they show, 

 by their many singularities of structure, that they have become 

 changed, or '' adapted," so as to fit them for a quite peculiar mode 

 of life. The beak, the tail, and the feet are the most obvious of these 

 changes. The first named is shaped like a pick, and has the horny 

 sheath of unusual density. By its means they are enabled to break 

 away the bark and wood of trees for the purpose of obtaining insects 

 sheltering therein, or for excavating holes designed for nurseries for 



