THE FOOD OF THE OTHER LAND ANIMALS 9 1 



great spotted cuckoo victimizes magpies and even crows, birds 

 which we look upon as unusually intelligent. In North and 

 South America most, but not all, of the small blackbirds known 

 as cowbirds because of their fondness for the company of 

 cattle have the same habit. The adults of most cuckoos are 

 caterpillar eaters (some eat lizards), and the cowbirds are 

 insectivorous. The jaegers, the skuas, the frigate birds, and, 

 to a lesser extent, the bald eagle rob other fish eating birds 

 of their prey, while the large gulls feed very generally on the 

 eggs and young of other sea birds and the crows and jays 

 destroy the eggs and young of birds in our woods and orchards. 

 Some birds, Hke the house wren, will destroy the eggs of other 

 birds for no apparent reason, as they do not eat them. 



As a group birds are chiefly animal feeders, devouring mainly 

 insects and other invertebrates, especially crustaceans, but 

 also all other vertebrates, including each other, and carrion; 

 many are fruit and seed, some honey, and a few leaf eaters. 

 The harder parts of plants, vegetable detritus and the fungi 

 are left practically untouched. 



In sharp contrast to the amphibians, reptiles and birds, the 

 mammals are chiefly vegetarians, especially leaf, twig and 

 root eaters. By far the largest group is that of the rodents, 

 including rats, mice, squirrels, porcupines, hares, rabbits, 

 beavers, voles, etc. These are mostly small but very numerous 

 in individuals, terrestrial or burrowing, more rarely tree in- 

 habiting or aquatic, and feed almost wholly on the roots, bark, 

 stems and leaves of plants, or on seeds or nuts. Some, espec- 

 ially the smaller mice, are very fond of insects and wull feed 

 largely upon them if they are able to get them. 



The sea-cows are all vegetarians, the marine forms eating 

 sea-weeds and those living in rivers water plants. The ele- 

 phants and the numerous hoofed animals and their allies are 

 all terrestrial and all leaf eaters, some consuming also twigs, 

 bark and roots, as well as lichens. A very few, like the pigs 

 are more or less omnivorous and will sometimes feed on other 

 animals. These creatures are of large size, nearly all, except 



