82 



The National Geographic Magazine 



From the Biological Survey 



A USEFUL BIRD OF PREY 



Swainson hawk. This bird saves the western farmer 

 $100,000 a year (see page 85) 



family contains more species than any 

 other group of birds. It is well that this is 

 so, for the destruction of weed seed is of 

 tremendous importance to the farmer, 

 whose trouble to keep ahead of the weeds, 

 great as it is now, would be vastly in- 

 creased were it not for the soberly clad 

 and unobstrusive little sparrows. We 

 may get an idea of the value of the serv- 

 ice these birds render by noting what is 

 done for the farmer by the tree-sparrow, 

 one of the most confirmed seed-eaters of 

 the group. A quarter of an ounce of 

 seed per day is a safe estimate of the food 

 of an adult tree-sparrow. On this reckon- 

 ing, in a state like Iowa, where agricul- 

 ture is relatively very important, tree- 

 sparrows annually eat about 875 tons of 

 weed seed : 



The total value of the principal field 

 crops of the United States for the year 

 1906 was about $3,500,000,000. If we 

 estimate that the combined consumption 



of weed seed by the sparrow 

 family results in an annual saving 

 of only 1 per cent of the value of 

 the crops, the sum total saved to 

 the farmer in 1906 was $35,- 

 000,000. 



Though seeds form the chief 

 part of the subsistence of spar- 

 rows, the destruction of seeds is 

 by no means all we have to thank 

 these birds for. They eat many 

 insects also, and seem to know 

 instinctively that while seeds are 

 excellent food for adult birds, 

 they are not necessarily good for 

 nestlings, and hence feed the lat- 

 ter almost exclusively on insects. 

 Sparrows, however, are not the 

 only birds that consume the seeds 

 of weeds. The eastern quail or 

 bobwhite is a confirmed eater of 

 weed seeds. Highly exteemed as 

 bobwhite is by the epicure for 

 food and by the sportsman as an 

 object of pursuit, he is probably 

 worth so much more as a weed- 

 destroyer that the farmer can ill 

 afford to have him shot, even 

 though the privilege is roundly 

 paid for. A bevy or two of quail 

 on a farm is an asset the value of 

 which no thrifty farmer should 

 overlook. Doves also are seed 

 eaters, especially the turtle-dove, whose 

 crop often is so packed with the seeds of 

 weeds that it can hold no more. 



The farmer has no quarrel with birds 

 that confine their attention to grass and 

 weed seeds, and welcomes their presence 

 always and everywhere. There are birds, 

 however, which eat such seeds as corn, 

 wheat, and barley, and whose place in the 

 farmer's esteem is by no means so well 

 assured — the crow and the blackbirds for 

 instance. There are several kinds of 

 blackbirds which at times attack crops as 

 also does the crow. The destruction by 

 the crow of meadow mice, and .of cut- 

 worms and other insect pests and the de- 

 struction of many kinds of insects by the 

 blackbirds, however, are considered in 

 most localities to offset all damage done 

 in other ways and even to leave a balance 

 in favor of the birds. 



