the object of determining their relationship to mankind. Dr. F. E. L. Beal of 

 this Bureau in his paper reporting on the relation of Cuckoos to agriculture says : 

 "The insect food of Cuckoos consists of beetles, grasshoppers, cicadas, bugs, 

 ants, wasps, flies, caterpillars and spiders, of Avhich grasshoppers and caterpillars 

 constitute more than three-fourths. In 129 stomachs examined, 2,771 caterpillars 

 were found, or an average of 21 in each. In May and June, when tent-caterpillars 

 are defoliating fruit trees, these insects constitute half of the Cuckoo's food. One 

 stomach was so full that the bird had evidently devoured the whole tent colony, 

 as there were several hundred in the stomach. This diet of hairy caterpillars 

 has a curious effect on the birds' stomachs, the lining of which is often pierced 

 by so many hairs as to be completely furred, the membrane itself being almost 

 entirely concealed. It seems hardly possible to overestimate the value of the 

 Cuckoo's work. All caterpillars are harmful, many of them are pests, and any 

 of them are likely to become so. The common tent-caterpillar formerly fed on 

 the wild cherry, but has now turned its attention principally to apple trees, some- 

 times completely defoliating them." 



How to Attract Birds 



By Joseph H. Dodson 



I began my work for native birds when I was still a boy. It has been 20 

 years since I built my first little bird house and experienced a keen thrill of 

 pleasure when a young pair of wrens came to this house and made their home 

 in my garden. During those first years there were many disappointments and 

 many experiments. I discovered to my surprise that birds are very particular 

 about their houses and that you can win them to you only by satisfying all their 

 little whims and prejudices. After a while you will find that these little whims 

 and prejudices of the birds are in reality generally based upon very good reasons. 

 For example, they are particular about the size of the opening. I discovered 

 that this is largely due to their fear of cats or larger birds. The number of holes 

 in the house is another point on which the birds have very decided ideas. I 

 found that this in reality is a matter of ventilation and that what the birds desire 

 is a house well ventilated but so arranged that there shall be no strong draft over 

 the nest. In other words, the birds are a great deal wiser than we are. 



It really took me five years to discover what I consider the ideal house for 

 wrens, the ideal house for martins, and the ideal house for bluebirds, for at 

 the same time I was learning how to place the houses and how to give further 

 service to the birds by arranging sheltered feeding shelves, food stations, and 

 bird baths. 



Here are a few general rules which should be observed when you make or 

 set out a bird house : 



First. — All bird houses should be at least a little weatherworn, for all birds 

 look with suspicion upon newness and abhor fresh paint. Yet the house shouIH 



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