THE THRUSHES AND THEIR ALLIES. 99 



this increase is first apparent and most evident in the ratios 

 of ants, an indication of the positive preference of the cat- 

 bird for this food. Nearly one-half of the forty-six per cent, 

 of insects eaten this month were ants. 1 ' Among the beetles 

 eaten was one striped cucumber-beetle, and among the bugs 

 were a few chinch-bugs. Blackberries formed the staple fruit 

 element. During the first half of September cherries, wild 

 fruits, and grapes formed seventy-six per cent, of the food. 

 The final percentages of the food for the five months are : 

 beneficial, forty-one; injurious, fifteen; neutral, forty- four. 



Five cat-birds examined in Nebraska by Aughey had eaten 

 one hundred and fifty-two Rocky Mountain locusts. Twenty- 

 five specimens shot during May in the Illinois orchard where 

 canker-worms were at work, and studied by Professor Forbes, 

 had eaten fifteen per cent, of canker-worms. This author 

 also reports having seen cat-birds " busily scooping out the 

 fairest side of the ripest early apples, unsurpassed in skill and 

 industry at this employment by the red-headed woodpecker 

 or the blue-jay.'" 



Evidently there is room for improvement in the economic 

 status of the adult cat-bird. But the dietary sins of the 

 parents are largely atoned for by the food of the young. In 

 1884 we examined the stomach contents of three Michigan 

 nestlings of this species : ninety-five per cent, of the food con- 

 sisted of insects ; two per cent, of spiders ; and three per 

 cent, of Myriapods. Sixty-two per cent, of the food con- 

 sisted of cutworms ; eleven per cent, of ground-beetles ; four 

 per cent, of grasshoppers ; three per cent, of May-flies, and 

 two per cent, of dragon-llies. The large proportion of cut- 

 worms strongly favors the usefulness of the species. Pro- 

 fessor Herrick's observations ' show that dragon-flies, caught 

 just as they emerge from the nymph state, are commonly fed 

 the nestlings, as are also " insect larvse, beetles, moths, millers, 



1 Home Life of Wild Birds, chap. viii. 



