UTILITY OF BIRDS. 53 



Almost every finch and sparrow is, therefore, insectivorous 

 for the first few weeks of its existence, not consuming seeds or 

 grain, until it has learned to provide for its own subsistence. 

 The old birds supply their young with larva, when this kind 

 of food is abundant, and when the tender state of their digestive 

 organs requires the use of soft food. Thus nature has provided 

 that even the granivorous birds should act as checks upon the 

 multiplication of insects, during the early stages of their 

 existence. The exceptions to this practice are the pigeon 

 tribe, that soften the grain in their own crops, before they give 

 it to their young ; and the hemp-birds, who wait until the 

 seeds of grasses and other plants are in the milk, before they 

 bring their young into the world, and then feed them upon the 

 soft milky seeds. 



The quantity of grubs and insects consumed by the feathered 

 race is infinite, and beyond all calculation ; and the facts related 

 of them show that birds require a much larger proportion 

 of food, compared with their size, than quadrupeds. My own 

 experience corroborates the accounts which I have selected 

 from the testimony of other observers. I took from their nest 

 two young bluebirds, which are only half the size of a jay, 

 and fed them constantly with my own hand for the space of 

 two weeks. These little birds would swallow twelve or more 

 large muckworms apiece daily, when they were supplied with 

 them, or other grubs or worms, in the same proportion, and 

 still seemed eager for more, and not over-fed. Another experi- 

 ment which I made with two young cat-birds, was attended 

 with results equally surprising. Their voracity convinced me 

 that the usual calculations bearing upon this subject are not 

 exaggerated. 



The usefulness of birds has been repeatedly demonstrated 

 by dissecting them, and examining their alimentary contents. 

 This method of studying their feeding propensities is not 

 attended with any liability to mistakes. "When we watch a bird 

 at a distance, we cannot be sure, in all particular instances, of 

 the character of his prey ; but if we find his crop or his gizzard 

 full of insects of a certain species, we cannot feel a rational 

 doubt that such insects are his natural food. And when we 

 consider that insect food is digested with much greater rapidity 

 than grain or seeds, we have reason to infer that each bird 



