242 PRODUCTIVE FARMING 



kill many other useful birds. These three should be learned 

 and killed on sight. 



Other Hawks, including the red tailed hawk, red shoul- 

 dered hawk, marsh hawk, Mississippi kite, Swainson's hawk, 

 American rough-legged hawk, sparrow hawk and broad 

 winged hawk, are all very useful, as their diet consists mainly 

 of rats, mice, and other small creatures that are very destruc- 

 tive to grain crops. Owls are also included in this list with 

 the useful hawks. It is said that hawks work by day and 

 owls by night, so that these birds work for the farmer twenty- 

 four hours every day. Nothing could be more friendly and 

 helpful than that. Farmers in turn can do no less than 

 protect these birds. 



Some Robin Arithmetic. The following paragraphs are 

 quoted from William Rittenhouse: "A pair of robins eat 

 two worms or insects every minute, all summer long, and 

 also raise one or two broods of young robins to do the same. 



"We count that the robin starts to look for the early 

 worm at five o'clock in the morning and keeps up his search 

 until five in the afternoon, that makes twelve hours, or seven 

 hundred and twenty minutes 1,440 worms a day for the 

 pair of birds. For at least four months the robins stay with 

 us. Robins live about fifteen summers if their enemies 

 usually men or boys with guns let them alone to do their 

 work. So in one lifetime a pair of robins could destroy 2,592- 

 000 bugs and worms. 



"Worms and insects when not interfered with, increase 

 at a frightful rate. One pair of potato bugs, if unmolested, 

 will increase to 55,000,000 in a single season. But one bird 

 in a minute, can gobble up one of these parent bugs, and thus 

 prevent the 55,000,000 from ever existing. To keep down 

 insect life is the robin's great occupation, and its foraging 

 begins early in the spring. Thus it destroys the early bugs 

 which, if let alone, would lay countless eggs and prepare 

 endless trouble for the farmer later on. 



