RELATIONS OF BIRDS TO ORCHARDS 289 



snow. Fortunately, however, hawks, owls, and other large 

 birds feed freely upon these pests and commonly keep 

 their numbers so reduced that little damage is done. But 

 in regions where the hawks and owls are ruthlessly perse- 

 cuted, the mice and other rodents become destructive, and 

 often cause the loss of valuable trees. 



It would perhaps be too much to expect that birds 

 should do no harm in orchards to offset the immense good 

 they do. In certain ways they doubtless cause damage, 

 but this is on the whole vastly less than the benefit they 

 confer. Some birds eat fruit, especially cherries, to a 

 serious extent. It is indeed probably true that in fruit- 

 growing regions there are often more robins than are 

 beneficial to horticulture. 



Birds also cause the spread of scale insects and probably 

 of fungous diseases, although little real injury is done in 

 these ways. At least one bird the true sapsucker 

 sometimes injures the trees by boring holes in the bark 

 and taking the sap, though this should not lead to the 

 killing of the beneficial woodpeckers, which the sapsucker 

 resembles. 



The chief damage done to fruit by birds generally 

 results from the extraordinary abundance of one kind of 

 bird. Thus, in the eastern region of the United States the 

 robin is often troublesome because it occurs in great num- 

 bers and attacks cherries and small fruits. On the Pacific 

 coast it is sometimes very destructive in olive orchards. 

 In the latter region birds are more injurious to fruit than 

 in the East, partly because of the scarcity of wild fruits. 

 The house-finch or linnet, the Brewer blackbird, the black- 

 headed grosbeak, and the California jay often become 

 serious pests, although each of these doubtless does con- 

 siderable good in other ways. 



