BIRDS I/I 



tralia and the United States than in Europe, because they 

 left behind them their native enemies and their new ene- 

 mies (crows, jays, shrikes, etc.) have not yet developed, to 

 a sufficient extent, the habit of preying upon them. Nature 

 will, perhaps, after a long time, restore the equilibrium 

 destroyed by presumptuous man. 



Protection of Birds. i. Leave as many trees and bushes 

 standing as possible. Plant trees, encourage bushes. 



2. Do not keep a cat. A mouse trap is more useful than 

 a cat. A tax should be imposed upon owners of cats. 



3. Make a bird house and place on a pole; remove 

 bark from pole that cats may not climb it, or put a broad 

 band of tin around the pole. 



4. Scatter food in winter. In dry regions and in hot 

 weather keep a shallow tin vessel containing water on the 

 roof of an outhouse, or out-of-the-way place for shy birds. 



5. Do not wear feathers obtained by the killing of birds. 

 What feathers are not so obtained ? 



6. Report all violators of laws for protection of birds. 



7. Destroy English sparrows. 



Migration. Many birds, in fact most birds, migrate to 

 warmer climates to spend the winter. Naturalists were 

 once content to speak of the migra- 

 tion of birds as a wonderful instinct, 

 and made no attempt 

 to explain it. As 

 birds have the warmest covering 

 V^^ of all animals, the winter mi- 



gration is not for the pur- 

 FIG. 315. -GREAT BLUE HERON, pose of escaping the cold ; it 

 in flight, balancing with legs. j s p ro bably to escape starva- 

 tion, because in cold countries food is largely hidden by 

 snow in winter. On the other hand, if the birds remained 



