FEEDING OF THE YOUNG. 205 



bers of insects required during- the breeding; season. 

 An instance of this is mentioned by Bindley, with 

 regard to some small American bird, which he calls 

 a creeper (Certhia), but which we suspect to be more 

 probably the house-wren (AnorthuraMdon). "From 

 observing-," he says, " its utility in destroying insects, 

 it has long been a custom, with the inhabitants of 

 many parts of the United States, to fix a small box 

 at the end of a pole, in gardens and about houses, 

 as a place for it to build in. In these boxes the ani- 

 mals form their nests and hatch their young ones ; 

 which the parent birds feed with a variety of different 

 insects, particularly those species that are injurious 

 in gardens. A gentleman, who was at the trouble 

 of watching these birds, observed that the parents 

 generally went from the nest and returned with in- 

 sects from forty to sixty times in an hour, and that in 

 one particular hour, they carried food no fewer than 

 seventy-one times. In this business they were en- 

 gaged during the greatest part of the day. Allowing 

 twelve hours to be thus occupied, a single pair of 

 these birds would destroy at least 600 insects in the 

 course of one day ; on the supposition that the two 

 birds took only a single insect each time. But it is 

 highly probable that they often took more*." 



Looking at the matter in this point of view, the 

 destruction of insectivorous birds has in some cases 

 been considered as productive of serious mischief. 

 One striking instance we distinctly recollect, though 

 we cannot at this moment turn to the book in which 

 it is recorded f. The numbers of the crows or rooks 

 of North America were, in consequence of state re- 

 wards for their destruction, so much diminished, and 

 the increase of insects so great, as to induce the 

 state to announce a counter reward for the protec- 



* Anim. Biogr. ii. 282, 6th edit. 

 t Belknap, Hist, of New Hampshire. 



T 



