CHARACTERS AND HABITS OF BIRDS 15 



The swimming faculty in these birds is of further interest be- 

 cause of its relation to the development of the body plumage. 

 If a land bird is placed in the water, the feathers are quickly sat- 

 urated, the water penetrating to the skin. A duck or other swim- 

 ming bird will remain in the water for hours without the water 

 penetrating the feathers. This is commonly supposed to be due 

 to the presence of a large amount of oil in the feathers, but the 

 difference in the oiliness of the feathers of fowls and of ducks 

 is not great enough to account for the difference in resistance 

 to the penetration of water. The peculiar quality of the plumage 

 of swimming birds is its density. If you take up a fowl and 

 examine the plumage you will find that it is easy to part the 

 feathers so that the skin can be seen. It may be done with the 

 fingers, or even by blowing gently among the feathers with 

 the mouth. Now try to separate the feathers of a duck so that 

 the skin will be visible. You find it much harder, because the 

 feathers are so thick and soft and at the same time so elastic. 

 The familiar phrase " like water from a duck's back " is not es- 

 pecially appropriate. The feathers on the back of most birds 

 are a very effective protection against rain. The feathers all 

 over a duck are such poor conductors of water that it is hard to 

 remove them by scalding. The structure of the plumage of 

 swimming birds adds to their buoyancy in the water. They 

 do not have to exert themselves to remain on the surface, but 

 float like cork. 



Foods and mode of digestion. All kinds of poultry and most 

 of our common wild birds are omnivorous eaters, but the pro- 

 portion of different foods usually taken is not the same in dif- 

 ferent kinds of birds. Some eat mostly grains, some mostly 

 animal foods. Some can subsist entirely on grass if they can 

 get it in a tender state ; others eat very little grass. The scratch- 

 ing birds like a diet of about equal parts of grain, leaves, and 

 insects. Pigeons and canaries live almost entirely on grains and 

 seeds, but like a little green stuff occasionally. 



