GREEN WOODPECKER 441 



food ; this consists largely of grubs and insects, which arc probed for 

 in the soil with the long beak. Occasionally, however, these birds 

 perch on trees ; and in the breeding-season they nest in hollow trunks, 

 laying from four to seven bluish-white eggs. Little in the way of nest- 

 making is effected ; but the nest-hole has invariably a most evil smell, 

 owing to accumulated filth. During incubation the hen sits almost 

 constantly, and is fed by her mate throughout this period. As a rule, 

 the crest is carried folded back flat on the head, but when the bird 

 alights from one of its short flights, or is under the influence of excite- 

 ment or alarm, the beautiful banded plumes are momentarily erected. 

 When the characteristic note is uttered the sides of the neck are puffed 

 out ; this action being accompanied, it is said, by striking the beak on 

 the ground. 



^ TTr J , With the green woodpecker, or yaffle, we come to the 



Gpeen Woodpecker, , . , r , ^^ \ ■ • 1 • 1 



,_ . . ■■,. y last and typical group of the so-called picanan birds; 



(Gecmus vindis). -^ ^ *=■ ^ , , . , . r 1 1 1 



all the members of which, inclusive of both wood- 

 peckers and their relative the wryneck, being classed in the family 

 Picidas. By the older naturalists all the European woodpeckers were 

 included in the single genus Picus, and by some ornithologists the 

 present species is still retained in that genus, under the name of Picus 

 vindis. There can, however, be little doubt that the colouring of 

 the plumage is a character of generic value among these birds ; and 

 according to the system here followed the original genus is represented 

 by the great black woodpecker {Piciis i/iartiits), while the yaffle and 

 its immediate relations are referred to a group apart. 



Doubtless the marked difference in the colour of the plumage of 

 the green and the spotted, or pied woodpeckers is to be accounted for 

 by differences in the habits of the species ; and it may be noted that 

 whereas the pied species spend most of their time in trees, the green 

 woodpecker is to a great extent a ground-bird. In this we have prob- 

 ably an explanation of the two types of colouring, the one being an 

 adaptation to harmonise with green grass and herbage, while the other is 

 obviously suited; to accord with the splashes of bright sunlight and 

 deep shade on tree-stems in summer. 



It is time, however, to refer to some of the leading features of the 

 group. Although there are woodpeckers with three toes, the species with 

 which we have here to deal, like the wryneck, have two toes turned 

 permanently forwards and two backwards — a feature distinguishing 

 them from other British birds except the cuckoo. On opening the beak 

 of either a woodpecker or a wr}'neck, the tongue will be found capable 



