THE WORLD'S BIRDS. 31 



fed by the foster-parents, and often eject the young 

 of these. 



Nest. — In non-parasitic forms rather rough, composed 

 of sticks, coarse grass, etc. ; in some cases open, 

 in others domed. 



Eggs. — Several ; varying in colour. In parasitic forms 

 they often resemble those of the host, and are 

 often spotted ; in non-parasitic forms plain white 

 or blue is the rule. 



Incubation. — About a fortnight, in the common 

 European Cuckoo. 



Food. — Chiefly insects, or other small animals — a few 

 feed chiefly or partially on fruit. They are re- 

 markable for being able to devour what other 

 birds usually refuse, such as hairy caterpillars and 

 toads. 



Gait. — In the short-legged tree-haunting forms an 

 awkward hop ; in the strong-legged running kinds 

 an active walk or run. All perch freely. 



Flight. — In the long-winged tree-haunting kinds swift 

 and elegant, with rapid action of the wings ; these 

 often catch prey on the wing. In the short-winged 

 kinds slow, heavy, and low, and not continued 

 far. The feet are extended behind in flight. 



Note. — Generally peculiar and characteristic, and 

 often articulate in character, varying much in 

 different species. Our bird is the only one which 

 cries " cuckoo " ; several have notes running up 

 the scale. 



Disposition and Habits. — Cuckoos are usually greedy 

 and unsocial birds, but probably have a good deal 

 of intelligence ; they are easily tamed. 



Economic Qualities. — Their destruction of injurious 

 insects, etc., makes them some of the most valuable 

 and important of birds. 



Captivity. — Only one species, the fruit-eating Koel 

 (Eudynamis honorata), is commonly kept, and that 



