460 MICHIGAN BIRD IJFE. 



23 per cent of the food. It is hardly necessary to point out tlie importance 

 of these facts. Remembering that, especially" in August, the blackbirds 

 are feeding in large flocks it is easy to see that at this time they must 

 consume grasshoppers by the million. Caterpillars formed 8 per cent of 

 the food in May and 4 percent in June; not a large amount, but forming 

 nevertheless an important item; many of the caterpillars eaten are cut- 

 worms, and among these the army-worm was recognized in six stomachs. 

 The Grackles eat large numbers of spiders, but these probably have small 

 economic significance. 



Practically the only harm done in the course of the insect-eating is the 

 destruction of a considerable number of predaceous l^eetles, ground beetles 

 belonging mainly to the family Carabida. The largest percentage of these, 

 13 percent, was found in June, and this would indicate that the birds were 

 doing some harm, for these beetles feed mostly upon other insects and are 

 therefore potentially beneficial. It must be remembered, however, that 

 these beetles are abundant at all times of the year, that they are con- 

 spicuous by their size and activity, and also, being often strong-scented, 

 are not generally eaten by other birds. It is therefore natural that a bird 

 like the Grackle should eat a considerable number of them, especially 

 as the taste and odor do not seem to be disagreeable. 



Taken all in all the facts seem to show conclusively that in the long run 

 the Bronzed Grackle is a valuable bird which does considerably more good 

 than harm, but the manner in which this good and evil are distributed 

 makes it impracticable for the average farmer to tolerate the bird invariably. 

 The good done is widely distributed; the harm is often concentrated on a 

 few acres. So long as the birds are but moderately abundant the good done 

 is pretty sure to outweigh the harm, even in the case of the fruit grower, 

 market gardener or small farmer; but when they become superabundant 

 instances of great injury are sure to occur and much complaint will follow. 

 It seems probable that it will be best not to attempt to protect the Grackles 

 by law at present, but to try to teach the farmer to let them alone so long 

 as they are doing no visible harm, only striving to limit their numbers 

 or drive them from his fields when they threaten serious injury. 



The Bronzed Grackle is one of the few birds for whose vocal performance 

 little can be claimed. It has nothing which, even by the most imaginative, 

 can be called a song, and its usual love notes have been aptly likened to the 

 creaking of a rusty hinge. In the case of other blackbirds numbers 

 sometimes modify the character of the individual performance so that a 

 chorus is musical, but in the case of the Grackle the larger the number 

 the 'greater the discord. 



TECHNICAL DESCRIPTION. 



Adult'male: Head and neck all round, metallic black, with purple, viulet, blue or green 

 reflections; rest of the body plumage above and below, black, with a distinct brassy gloss, 

 tlie line between neck and body sliarply defined; wings and tail with purplish or violet 

 gloss, never bluish; bill and feet black; iris bright yellow. Adult female: Decidedly 

 smaller and duller, the head and neck not noticeably different, but the body plumage 

 lacking much of the metallic luster. Young: Similar at first to adult females, but even 

 duller, the body plumage mostly slate color, with no metallic reflections; before moving 

 southward, however, the sexes are distinguishable by the plumage. 



Male: Length 12 to 13.50 inches; wing 5.45 to 5.95; tail 5.25 to 5.90 (its graduation 

 1.15 to 1.60); culmen 1.12 to 1.26. 



Female: Length 11 to 11.50 inches; wing 5 to 5.25; tail 4.80 to 4.90. 



