232 NATURE STUDY. 



side. So, at the present day, tail feathers grow, not like the webs on 

 the shaft of a feather, but fan-like, from a composite mass of bone. 



Now that we have evolved our modern bird's tail, let us see to 

 what uses it may be put, and a fine place to do this is in the New 

 York Zoological Park. Of course, its use as an aid to flight is the 

 first thought that comes to our mind, and rightly, too, for the parts 

 which it plays in this respect in various birds are many. The tail is 

 used as a rudder, especially when it is long and powerful, enabling 

 birds such as tropic birds and magpies to make quick turns in the 

 air. Tails sometimes perform the function of brakes. When a 

 great pelican settles gradually towards the surface of the water, 

 the tail, widespread and lowered, is of great importance in regulat- 

 ing the shock of alighting. The tail is aided in this function of 

 brake by the great expanse of web between the toes, both feet being 

 comically stretched out in front. 



Birds which have very short tails are unable to turn quickly, and 

 their flight is verj' direct, or even when there is a long tail, if it is 

 principally for an ornament and not well muscled, it is of little use 

 in helping its owner to change the direction of flight. 



Among many other uses of tails we must mention props. Wood- 

 peckers and creepers really sit on their tails, the feathers of which 

 are stiffened, and with just enough resistance at their tips to admit 

 of their bending into and making use of every crevice in the bark. 

 As we watch a brown creeper hop rapidly up a tree trunk, never 

 missing a foothold, no matter what smooth places it may encoun- 

 ter, we say to ourselves how impossible this mode of progression 

 would be without the all important caudal appendage. But here, 

 as everywhere, Nature confronts us with surprises. Our natural 

 philosophers tell us that the law of gravitation is universal, and 

 yet in almost any grove of trees in winter we will find what are ap- 

 parent exceptions. Associated with the brown creepers, little blue 

 and white birds will often be seen — nuthatches — which run and hop 

 merrily over the branches, upside down, wrong side up, any way, 

 any place which promises an insect tidbit. And most wonderful of 

 all, it is only by means of their eight little claws that they do this. 

 The rather short tail is often bent far forward over the back, and 

 in every case never touches the bark. 



Even the innate characteristics of birds are often portrayed in the 

 manner of carrying the tail ; quiet, soft mannered birds carrying it 

 low beneath the wing tips, while active, nervous species carry it 

 more or less raised. The peacock's real tail consists of small 

 brown feathers which serve as a support to the magnificent train of 

 feathers growing from the lower back. 



