BIRDS 291 



mimics of the voices of other animals. The parrots vary 

 ill size, from tire love bird, about the size of a sparrow, to 

 the macaws, which often measure three feet from tip of bill 

 to tip of tail. The only parrot found in the United States 

 is the Carolina parrakeet. Formerly this parrot was found 

 as far north as the Gi-eat Lakes, Ijut now it is confined to 

 Florida. It is very fond of cultivated grains and this has 

 been one cause of its exterminati(jn (Fig. 197). 



The toes of parrots, like those of woodpeckers and cuckoos, 

 are in paii's. One pair points backward and one pair forward. 



Perching birds. — This group of birds contains over six 

 thousand species, more than all the others combined. 

 Nearly all the familiar birds belong to the perehers. The 

 crows, jays, orioles, robins, bobolinks, sparrows, mocking 

 birds, thrushes, etc., are familiar examples. They are the 

 most highly developed of all the birds, and stand at the 

 heatl in complexity of organization. Tlie feet of the perehers 

 tliffer from those of tiie jmrrots in having one toe pointing 

 backwards and three toes extending forward, thus enaljling 

 them to grasj) the object on which they are resting. Many 

 of them are very sweet singers. The mocking bird is con- 

 sidered first in the range and variety of its notes. To the 

 \\Titer, however, the song of no bird will ever awaken so 

 much joy or will linger so long in the niemor}? as the notes 

 of the Wilson's thrush lieard lightly rolhng and lingering 

 through a wooded glen on a summer eve at twilight. In 

 the mammals, the vocal cords by which sound is produced 

 are situated at the upper end of the windpipe in the larynx. 

 In the singing birds a structure kno\Mr as the "syrinx," 

 or "lower larynx," is situated at the lower end of the vind- 

 pipe, next to (he lungs. It is here that the sounds are sup- 

 posed to be iii()(hiced. 



