48 THE WORLD S BIRDS. 



nest is always damp, and the eggs are covered with 

 weeds by the sitting bird when leaving it. 



Eggs. — Several ; oval in shape, and pure white when 

 laid, but becoming stained buff to chocolate by the 

 wet vegetable matter of the nest. 



Incubation. — About three weeks. 



Courtship. — Chiefly consists in meeting face to face 

 and uttering various notes ; no special display. 



Food. — Small aquatic animals and aquatic plants ; 

 insects captured from the surface. Many species 

 swallow their own feathers. The digestion is 

 powerful ; no castings are ejected, even the feathers 

 being apparently digested. 



Gait. — On land semi-erect and awkward, especially 



in the large species ; it is an effort for the bird to 



rise up, and it easily falls down. They have great 



powers of swimming and diving; under water the 



legs are used simultaneously, the wings not at all. 



Flight. — Direct and rapid, with the neck and legs 

 extended, and continuous wing-beats ; mostly 

 performed at night. The birds have much difli- 

 culty in starting, and alight breast first, with the 

 legs trailing and wings working continuously. One 

 species, Podicipes micropterus, the Flightless Grebe 

 of Lake Titicaca in the Andes, has such small 

 wings that it cannot fly at all. Most will dive 

 rather than fly. 



Disposition and Habits. — Grebes are intelligent, 

 courageous, and much attached to their young. 

 Very wary when persecuted, they become tame and 

 inquisitive where protected. 



Note. — A croak in the larger species, an almost musical 

 trill in some Dabchicks. 



Economic Qualities. — These birds are hardly to be 

 reckoned as either beneficial or destructive. The 

 skins of the Great Crested Grebe {Podicipes crislaitts) 

 are utilized as furs, and it is considered to give good 



