Tails 



413 



the borders of streams. We are all familiar with the tip- 

 ping of the tail in sandpipers, and, including the Green 

 Heron, we will see much the same motion in birds which 

 haunt the stream borders ; e\'en in the Water Thrush the 

 same habit prevailing, although, as we saw in the pre- 

 ceding chapter, this bird is closely related to the bright- 

 coloured warblers of our tree-tops. The wagtails have 

 received their name from this same habit, of which no 

 explanation has yet been offered. 



The Road-runner, a ground cuckoo of the Western 

 plains, has a tail as long as its entire body, which is as 

 expressive as the gestures of a Frenchman. When sitting 

 quietly in the shade of a mesquite-bush in Mexico, I have 

 seen one of these birds dash into sight and drop, like an 

 arrow, upon a luckless lizard. At the moment of attack 

 all ten tail-feathers of the bird were wide-spread and 

 a-tremor, indicative of the extreme excitement attendant 

 upon the capture of the reptile. While eating what choice 

 parts were desired, the tail was folded and lifted out of 

 the way. Soon the bird spied some motion of mine, and 

 with the suspicion came the high extended neck, while the 

 tail turned up and forward, until almost touching the 

 bird's head. A second motion on my part, and the tail 

 manoeuvred to a line and trailed limply after the bird, 

 as it half-flew, half-leaped to a high rock and on out of 

 sight. 



The white under sides of the tails of the wild rabbit 

 and the white-tailed deer have been explained as warning 

 signals to others of the family or herd: white guides 

 which the less experienced members may follow and so 



