66 THE WORLD'S BIRDS. 



flowers ; they usually feed when hovering on the 

 wing over the flowers. 



Gait. — They seem never to walk at all ; when perching 

 they sometimes move sideways along the twig, but 

 usually sit still. 



Flight. — Very powerful and peculiar, by extremely 

 rapid beats of the wing, so that a humming noise 

 is often produced. They fly very quickly in a 

 straight line, and excel all birds in power of hover- 

 ing ; but do not usually remain on the wing for long 

 together. 



Note. — A mere chirp or squeak ; one species, the 

 Vervain Humming-Bird (Mellisuga minima), is 

 a singing bird, however. 



Economic Qualities. — They are very ornamental 

 and useful as insect-destroyers and flower-fer- 

 tilizers. 



Disposition and Habits. — They are quarrelsome and 

 unsociable, but show considerable intelligence. 

 They have a curious trick of wiping the bill with 

 one foot. 



Captivity. — They have seldom been kept successfully 

 for long, but several species have been brought to 

 Europe and lived for some weeks at our Zoological 

 Gardens, or even months elsewhere. Some substi- 

 tute for their insect food should always be provided, 

 as they cannot live long on syrup alone. « 



Distribution and Important Species. — The New 

 World, chiefly in the southern half thereof ; there 

 are about five hundred species. Some species are 

 migratory, and of these some even reach Alaska 

 and Canada. Others range high up the Andes. 

 The most generally known is the Ruby-throat 

 (Trochilus colibris), of the United States and 

 Canada, metallic green, with white underparts, and 

 red throat in the male. 



