INTRODUCTION OF BIKDS. 113 



An iinfortimate popular error greatly magnifies the injury 

 done to the crops of grain and leguminous vegetables by wild 

 bii'ds. Yery many of those generally supposed to consume large 

 quantities of the seeds of cultivated plants really feed almost ex- 

 clusively upon insects, and frequent the wheat-fields, not for the 

 sake of the grain, but for the eggs, larvae, aud fly of the multi- 

 plied tribes of insect life which are so destructive to the harvests. 

 This fact has been so well estabhshed by the examination of the 

 stomachs of great numbers of bu'ds in Europe and the United 

 States, at different seasons of the year, that it is no longer open 

 to doubt ; and it apjDears highly probable that even the species 

 which consume more or less grain, generally make amends by 

 destroying insects whose ravages would have been still more in- 

 jurious.* On this subject, we have much other evidence besides 



migration to the banks of the Nile. Before he "was able to fly again, he was 

 caught, and the flag of the nation to which the palace belonged was tied to his 

 leg, so that he was easily identified at a considerable distance. As his wing 

 grew stronger, he made several unsatisfactory experiments at flight, and at 

 last, by a vigorous effort, succeeded in reaching a passing ship bound south- 

 ward, and perched himself on a topsail-yard. I happened to witness this 

 movement, and observed him quietly maintaining his position as long as I 

 could discern him with a spy-glass. I supposed he finished the voyage, for 

 he certainly did not return to the palace. 



* Even the common crow has found apologists, and it has been asserted that 

 he pays for the Indian corn he consumes by destroying the worms and larvae 

 which infest that plant. 



Professor Treadwell, of Massachusetts, found that a half -grown American 

 robin in confinement ate in one day sixty-eight worms, weighing together 

 nearly once and a half as much as the bird himself, and another had previously 

 starved upon a daily allowance of eight or ten worms, or about twenty per 

 cent, of his own weight. The largest of these numbers appeared, so far as 

 could be judged by watching parent birds of the same species as they brought 

 food to their young, to be much greater than that supplied to them when fed 

 in the nest ; for the old birds did not return with worms or insects oftener 

 than once in ten minutes on an average. If we suppose the parents to hunt 

 for food twelve hours in a day, and a nest to contain four young, we should 

 have seventy-two worms, or eighteen each, as the daily supply of the brood. 

 It is probable enough that some of the food collected by the parents may be 

 more nutritious than the earthworms, and consequently that a smaller quan- 

 tity sufficed for the yoimg in the nest than when reared imder artificial con- 

 ditions. 



The supply required by growing birds is not the measure of their wants 

 after they have arrived at maturity, and it is not by any means certain that 



