158 BRANCH VERTEBRATA. 



appear. It will often imitate the cry of a young bird, to 

 induce the old to leave their hiding-places.* 



The Owls comprise about two hundred species. The 

 sexes are colored alike, and the mottled markings are 

 FIG 269 nearly as apparent in the young as the 



old.f So soft and downy are the feath- 

 ers, that in its nocturnal foraging the 

 Owl's flight is noiseless as a shadow ; 

 while its acute sense of hearing detects 

 the feeblest rustling as of a mouse. Liv- 

 ing upon injurious vermin, it deserves 

 protection from the ruthless war waged 

 against it. The Owl is the only bird 

 that can bring both eyes simultaneously 



The Great-horned, with a single exception, is the 

 largest Owl of the United States. It is often called the 

 " Cat Owl" as its tufts, erectile at will, give its head a 

 sinister aspect, quite feline. 



ORDER PSITTACI (sit'ta si). 



The Parrots have a thick bill, the upper mandible 

 strongly hooked at the end, with a naked space at the 



* When a Bird of Prey wishes to kill an animal with its claws, it has only 

 to rest down with its own weight, and the bending of the legs will thrust its 

 talons deep into the flesh of its victim (see Fig. 217). The principle is illustrated 

 in the roosting of a common fowl. Its grasp of the perch is involuntary, the 

 muscles of the leg being so contrived that when the limb is bent the foot closes 

 and remains so without any exertion of the will ; and when straightened, the 

 toes open and the hold is relaxed. A bird can not keep its foot open when its leg 

 is bent. This may be verified by watching a fowl walking. It closes its toes as 

 it lifts its foot, and spreads them out aorain as they touch the ground. 



t Some species are dimorphous (double-form) in plumage. Two young of the 

 same sex in the same nest may start with different markings, and retain them 

 through life. 



