4^.^. 



PURPLE MARTIN (Progne subis). 



Length, about 8 inches. 

 Range: Breeds throughout the United States 

 and southern Canada, south to central Mexico; 

 winters in South America. 



Habits and economic status: This is the 

 largest as it is one of the most beautiful of the 

 swallow tribe. It formerly built its nests in 

 cavities of trees, as it still does in wild districts, 

 but learning that man was a friend it soon 

 adopted domestic habits. Its presence about 

 the farm can often be secured by erecting houses 

 suitable for nesting sites and protecting them 

 from usurpation by the English sparrow, and 

 every effort should be made to increase the 

 number of colonies of this very useful bird. 

 The boxes should be at a reasona,ble height, 

 say 15 feet from the ground, and made inac- 

 cessible to cats. A colony of these birds on a 

 farm makes great inroads upon the insect popu- 

 lation, as the birds not only themselves feed 

 upon insects but l*ear their young upon the 

 same diet. Fifty years ago in New England it 

 was not uncommon to see colonies of 50 pairs 

 of martins, but most of them have now vanished 

 for no apparent reason except that the martin houses have decayed and have 

 not been renewed. More than three-fourths of this bird's food consists of wasps, 

 bugs, and beetles, their importance being in the order given. The beetles include 

 several species of harmful weevils, as the clover-leaf weevils and the nut weevils. 

 Besides these are many crane flies, moths, May flies, and dragonflies. 



BLACK-HEADED GROSBEAK (Zamelodia melanocephala). 



Length, about 8J inches. 



Range: Breeds from the Pacific coast to Nebraska and the Dakotas, and from 

 fiouthern Canada to southern Mexico; winters in Mexico. 



Habits and economic status: The black- 

 headed grosbeak takes the place in the West 

 of the rosebreast in the East, and like it is 

 a fine songster. Like it also the blackhead 

 readily resorts to orchards and gardens and is 

 common in agricultural districts. The bird has 

 a very powerful bill and easily crushes or cuts 

 into the firmest fruit. It feeds upon cherries, 

 apricots, and other fruits, and also does some 

 damage to green peas and beans, but it is so 

 active a foe of certain horticultural pests that we 

 can afford to overlook its faults. Several kinds 

 of scale insects are freely eaten, and one, the 

 black olive scale, constitutes a fifth of the total 

 food. In May many cankerworms and codling 

 moths are consumed, and almost a sixth of the 

 bird's seasonal food consists of flower beetles, 

 " which do incalculable damage to cultivated 



flowers and to ripe fruit. For each quart of fruit 

 consumed by the black-headed grosbeak it de- 

 stroys in actual bulk more than 1§ quarts of 

 black olive scales and 1 quart of flower beetles, 

 besides a generous quantity of codling-moth 

 pupas and cankerworms. It is obvious that 

 such work as this pays many times over for 

 the fruit destroyed. (See Biol. Survey Bui. 32, 

 pp. 60-77.) 



68o 



