188 



SMALL ANIMALS AND INSECTS. 



[Chap. II. 



the seventli 31 worms. They seemed insufficient, and the bird appeared to 

 be losing plumpness and weight. He began then to weigh both the bird 

 and its food, antl tlie results were given in a tabular form. On the fifteenth 

 day, he tried a small (quantity of raw meat, and finding it readily eaten, in- 

 creased it gradually, to the exclusion of worms ; with it the bird ate a large 

 qiumtity of earth and gravel, and drank freely after eating. By the table, 

 it appears that thuugli the food was increased to 40 worms, weighing 20 dwt. 

 on the eleventh day the weight rather fell off; and it was not until the 

 fourteenth day, when lie ate GS worms, or 34 dwt., that he began to increase. 

 On this day the weight of tlie bird was 24 dwt. ; he therefore ate 41 percent. 

 more than his own weight in twelve houi-s, weighing after it 29 dwt., or 15 

 per cent, less than the food he had eaten in that time. The length of these 

 M-orms, if laid end to end, would be about fourteen feet, or ten times the 

 length of the intestines. To meet the objection that the earth-worm contains 

 but a small amount of nutritious matter, on the twenty-seventh day he was 

 fed exclusively on clear beef, in quantity 23 dwt. ; at night, the bird weighed 

 52 dwt. — but little more than twice the amount of flesh consumed durinsr the 

 day, not taking into account the water and earth swallowed." 



A man eating in the same proportion woidd consume 70 lbs. of flesh and 

 five gallons of water. Four young robius would require, according to the 

 consumption of this bird, 250 worms, or their equivalent in insects or other 

 food, daily. After the thirty-second day the bird was fed for eighteen days 

 on an average of 15 dwt. of meat, two or three earth-worms, and a small 

 quantity of bread each day ; the whole being equal to 18 dwt. of beef, or 

 36 dwt. of earth-worms ; and it has continued to cat this amount to the 

 present time. The food M'as never passed undigested ; the excretions were 

 made up of gravel and dirt, and a small quantity of white semi-solid urine. 



Every admirer of trees may derive from . these facts a lesson, showing the 

 immense power of birds to destroy the insects by which our trees, especially 

 our apples, elms, and lindens, are every few years stripped of their foliage, 

 and often many of them killed. The food of the robin, while with us, con- 

 sists principally of earth-worms, various insects, their larvre and eggs, and 

 a few cherries ; of worms and cherries they can procure but few, and those 

 during but a short period, and they are obliged therefore to subsist princi- 

 pally upon the great destroyers of leaves, canker-worms, and some other 

 kinds of caterpillars and bugs. If each robin, old and young, requires for 

 its support an amount of these equal to the weight consumed by this bird, it 

 is easy to see what a prodigious havoc a few hundreds of these must make 

 upon the insects of an orchard or a park. Is it not, then, to our advantage, 

 to purchase the service of the robins at the price of a few cherries ? 



Speaking upon this paper, the editor of the Xewark (N. J.) Advertiser 

 says : 



" There is so little knowledge of the habits of birds, and their ways and 

 means of gaining a living in the world, that an^-thing which promises to 

 produce better acquaintance with them ought to be generally made known. 



