THE WORLD'S BIRDS. 57 



Space from bill to eyes, which are nearly always 

 yellow. 



Young.— Helpless, scantily clothed with hair-like 

 down ; gaping for food, and constantly uttering a 

 cry like get-get-get. 



Nest.— An open platform of twigs, usually in trees ; 

 sometimes in rushes or on rocks. 



Eggs. — Several ; coloured or white, spotless. 



Incubation.— From between two and three to be- 

 tween three and four weeks. 



Courtship. — Crest and ornamental back-plumes raised. 



Food.— Small animals, especially fish. They usually 

 stand waiting for food, and do not search about for 

 it much. Some feed much on insects. 



Gait. — A slow walk ; only a few run. They are quite 

 at home in trees, and some climb actively about in 

 reeds. They can swim, but rarely do so. 



Flight.— Heavy, with slow or rapid continuous strokes 

 of the wing, according to the size of the species, 

 the larger ones using the slower stroke. When 

 flying, the neck is drawn in, and the legs stretched 

 out, the hind-toes elevated, and the points of the 

 wings incHne downwards. They do not sail or 

 soar except when about to ahght. 



Note. — A croak or booming sound. 



Disposition and General Habits.— Generally slug- 

 gish, surly and savage, unsociable except when 

 breeding, and then constantly quarrelling. They 

 strike at the eyes when fighting. 



Economic Qualities.— They are destructive to fish, 

 but also destroy many injurious animals, such as 

 mice and insects. The Common Bittern is good 

 eating, and the Egrets supply plumes, obtained 

 most cruelly from breeding birds. 



Captivity.— They live well, but have seldom bred. 

 The Night Heron (Nycticorax griseus) has, how- 

 ever, bred in the London Zoological Gardens 



