FOREST, AND ITS FAUNA 47 
note the grouse and their allies ; the grosbeaks and their 
relatives the crossbills ; the woodpeckers and wryneck ; 
the nutcrackers, jays, and their allies. 
Grouse belong to the same family as the ptarmigan, 
and are especially characteristic of northern latitudes. 
The abundance of berry-bearing bushes, of which we 
have already spoken, both in the tundra and in the 
taiga, is an important factor in their distribution, for 
these berries constitute a considerable part of their 
food. In the Asiatic taiga we find the black grouse 
(Lyrurus tetrix), the larger capercaillie (T'etrao urogallus), 
and the hazel grouse (T'etrastes bonasia), while in the 
Canadian forest is found the Canadian grouse (Cana- 
chites canadensis), often called a partridge, and also the 
ruffed grouse (Bonasa umbellus). 
The woodpeckers are birds showing remarkable 
adaptations to an arboreal habitat. The feet are well 
fitted for climbing, and the most highly specialized 
forms have stiffened tails, which aid in the climbing 
process. The beak is powerful and chisel-shaped, 
enabling the birds to excavate holes in wood, and also 
to lever off bark, while the long, viscid, worm-like 
tongue enables them to capture the insects thus 
exposed. Woodpeckers are very widely distributed, 
a few only ranging into the northern woods. Among 
these are the green woodpeckers (Gecinus), found in 
the temperate regions of the Old World, and the 
spotted woodpeckers (Dendrocopus), of both Old and 
New Worlds. Related is the curious wryneck (Lynx 
torquilla), found in summer in Northern Europe and 
Asia, which is without the stiff tail and climbing habits 
of the woodpeckers. 
We have spoken of the edible seeds of the Cembra 
pine, and of the appreciation in which they are held 
