“‘The yellow-billed cuckoo eats hundreds of tent caterpillars in a day.
“‘Seed-eating birds destroy myriads of seeds of destructive weeds—actually eating hundreds of tons of seed.
“‘The Department of Agriculture of the United States estimates that the tree sparrow alone saves the American farmer $90,000,000 in a year by eating seeds of weeds.’”
“That isn’t the English sparrow,” laughingly interrupted Mary Frances.
“No,” replied Billy, “not so much can be said in its favor.”
“How do people know what the different birds eat?” asked Mary Frances. “Did someone watch to see what each different bird took for a meal?”
“No.” Billy referred to his clipping. “Scientists have examined the contents of the stomachs of the birds, and have learned what food each kind of bird uses. There was a time when people imagined that robins stole so many cherries and berries that it was a good deed to kill them. Now they have found that they destroy so many injurious insects that they do not begrudge them a few cherries. Besides, if mulberry trees are planted nearby, they will prefer their fruit to the cherries.”
“Oh, Billy,” cried Mary Frances, “isn’t it wonderful! Not only do birds help us by destroying harmful insects and seeds, but they help us by their beauty. I believe they are the most beautiful of living things! They could have helped us just as much, and have been as ugly as—cutworms.”
“Yes,” laughed Billy, “I believe that is so, but it takes a girl to think such things out. The most remarkable fact to me, however, is that without birds we would die of starvation. It has been estimated that if they were absent for one season alone, the United States would lose over $300,000,000, and if they disappeared entirely, agriculture and farming would be impossible within a few years.”