THE ECONOMIC BIOLOGY OF VERTEBRATES 485 



How protect birds? 



1. Obey and enforce protective laws. 



2. Restrain their enemies. 



(a) Plume hunters and game hogs. 

 (6) Cats, red squirrels, snakes. 



(c) Cooper's hawk, sharp-shinned hawk, horned owl, English 

 sparrow. 



3. Preserve forests and trees. 



4. Provide winter food and summer homes. 

 V. Mammals. 



1. Food, meat and milk (ungulates) 



meat (various forms except dog and cat groups). 



2. Clothing, wool (sheep, goat, camel, llama). 



fur (rodents and carnivora). 

 leather (ungulates, etc.). 



3. Various products. 



From whale: oil, wax, "whalebone," ambergris. 



From elephant: ivory. 



From various mammals: horn and bone. 



4. Transportation. 



Horses, oxen, camels, reindeer, dogs, goats, llamas, water buffalo. 



5. Pets. 



Dogs, horse, cat, etc. 

 "Domestic animals." 



6. Harmful mammals. 



(1) Large carnivora (lion, tiger, wolf). 



(2) Rodents (rats, mice, squirrels). 



waste foodstuffs, 

 transmit disease. 



