USEFULNESS OF BIRDS. 205 



The activity of birds, as shown in running, climbing trees, 

 hopping or flying, together with their powers of vision, 

 renders them particularly adapted for searching out, over- 

 taking and destroying insects. Birds often assemble where 

 insect outbreaks occur, and assist in checking great insect 

 invasions. 



In a search through agricultural, entomological and orni- 

 thological literature, we find many instances on record in 

 both hemispheres where birds have been instrumental in 

 saving crops or forests by destroying injurious insects. 

 Samuels states that in 1847, as an immense forest in Pom- 

 erania was on the brink of being utterly ruined by caterpil- 

 lars, it was suddenly and very unexpectedly saved by a flock 

 of cuckoos, who established themselves in the place for a 

 few weeks and thoroughly cleaned each tree.* 



During the great locust invasions in the West the investi- 

 gations of Professor Aughey, as published in the first report 

 of the United States Entomological Commission, showed 

 that birds were among the greatest enemies of locusts, and 

 that in many instances when the farmers had given up the 

 battle against the " grasshoppers," the crops were saved by 

 the flocks of birds that descended upon the fields, destroying 

 immense numbers of the feeding locusts. f 



Many instances are on record where a great increase of 

 insect pests has followed the destruction of birds. George 

 Kearly, in the "Entomologist's Weekly Intelligencer," 

 speaks of an outbreak of insect pests in a park at Brussels, 

 in which the gypsy moth was one of the chief oflenders, hav- 

 ing stripped well-nigh all the trees of their foliage. He says 

 this great increase of insects followed soon after and was 

 caused by the destruction of sparrows and other birds in the 

 park, by order of the authorities. J In a letter recently 

 received from J. O. Clercy, secretary of the Society of 

 Natural Sciences, Ekaterinburg, Russia, he states that the 

 ravages of two species of cutworms and some ten species 



* E. A. Samuels, in report of Massachusetts State Board of Agriculture, 1865-66, 

 page 117. 

 t Report of the United States Entomological Commission, 1877, page 338. 

 X The "Entomologist's Weekly Intelligencer," 1858, Vol. 4, page 192. 



