Nature's Militia 273 



One redstart, kept in a room, has been known to eat 

 six hundred flies in an hour; and one blackcap has cleared 

 about two thousand greenflies from the rose-trees in a 

 greenhouse in the course of a few hours. 



The titmouse is another most active little bird, con- 

 stantly engaged in the hunt for food, creeping into rolled-up 

 leaves, and devouring by the thousand eggs which would 

 produce many more hairy caterpillars than the cuckoos 

 could dispose of. 



The wren, like the titmouse, is perpetually eating, and 

 feeds her young thirty-six times in an hour; the cuckoo, 

 too, eats all day long, every five minutes or so, and 

 devours about one hundred and seventy good-sized cater- 

 pillars in the day; and as each of these caterpillars, if 

 allowed to reach the butterfly state, might lay some five 

 hundred eggs, every cuckoo rids us of a possible eighty- 

 five thousand odd caterpillars daily! 



And the work goes on vigorously in winter, as well as 

 in spring and in summer, for with all the vigilance of the 

 birds, caterpillars and grubs innumerable escape and pass 

 into the chrysalis state, which they spend — as much of it 

 as they are allowed — in cracks and crannies, in sheltered 

 nooks, on twigs and trunks of trees, on palings and walls, 

 and in the ground. These supply food to the many insect- 

 eating birds which do not migrate; and but for the unceas- 

 ing labors of these stay-at-homes we should be overrun 

 with insects in the spring, in spite of all that is done in 

 the summer; for each chrysahs devoured saves us from 

 some hundreds of grubs or caterpillars later on. 



If any one needs proof of what would certainly follow 

 the extermination of the birds, he need only look at the 

 island of Jamaica, where they are at present very scarce. 



