Aves. 235 



hoo-hoo, hoo-hoo," the last note prolonged with a circum- 

 flex accent. 



The common little screech owl shows an interesting varia- 

 tion in color. Two colors are found, a gray and a reddish. 

 It was at first thought they belonged to different species, 

 but these two colors have been found in young of the same 

 brood. The difference seems to have 'no relation to age, 



FIG. 140.. TURKEY BUZZARD. 



From Grinnell's Our Feathered Friends. 



sex, or geographical distribution, nor do there seem to be 

 intermediate individuals. There are evidently two styles 

 of dress with the screech owls. This occurrence of two 

 styles of plumage is known as "color dimorphism." 



The vultures are degenerate Raptores, usually carrion 

 eaters. The head and neck are usually bare, and the bill 

 and claws weaker than in the above-described forms. Many 



