Feet and Legs 373 
western part of the United States much of the vegetation 
consists of prickly cacti and thorny mesquite, most un- 
pleasant to perch upon, and here we find the Road-runner, 
a kind of ground cuckoo, who has the fore-and-aft toe 
arrangement of his arboreal relations, but whose terres- 
trial life has developed remarkable powers of running 
and leaping. One of these birds can outstrip a horse 
for a hundred yards or more and, almost without effort, 
can leap upward ten or twelve feet, to all appearances 
unaided by its wings. 
The owls can move their outer toes backward or for- 
ward at will, thus being able to assume the arrangement 
of toes both of a crow and of a parrot. However the 
yoke, or two-and-two, plan is the one most commonly seen 
among these birds. With such an automatic vise-trap 
ready to descend silently and with deadly swiftness upon 
him, the little mouse in the grass has indeed need to be 
ever on the alert. The talons of owls are curved and 
under the control of tendons of great strength. Their 
chief use is to capture living prey and then to hold it firmly 
while it is torn to pieces by the beak. 
The deserts and plains where the Road-runner dwells 
are also the home of the Burrowing Owl, Fig. 351, which 
finds in its sharp little talons admirable picks and shovels, 
certainly a novel use for yoked toes. The feet and toes 
of birds are, in zero weather, their most vulnerable points 
(except their eyes), and they are most liable to be frozen. 
In the black wastes of the frozen boreal regions, the Arctic 
Owl is able to defy the intense cold, by means of a furry 
covering of hair-like feathers, which extends to the very 
