BRONZED GRACKLE 405 



animal and 69.7 percent vegetable matter. In addition to insects 

 the animal matter was composed of spiders, myriapods, crayfish, 

 earthworms, sowbugs, snakes, snails, fish, frogs, toads, salamanders, 

 lizards, birds, eggs, and mice. 



Insect food constitutes 27 percent of the entire food for the year, and is the 

 most interesting part of the bird's diet from an economic point of view. When 

 it is examined month by month, the smallest quantity appears in February (less 

 than 3 percent of the whole food) — In March it rises to one-sixth, and steadily 

 increases till May when it reaches its maximum of five-eighths of the whole; it 

 then decreases to one-sixth in October and appears to rise again in November. * * * 

 The great number of insects eaten in May and June is due in part to the fact that 

 the young are fed largely on this kind of food. 



Analysis of the insect food presents many points of interest. Among the most 

 important families of beetles are the scarabaeids, of which the common June bug 

 or May-beetle and the rose bug are familiar examples. These insects are eaten, 

 either as beetles or grubs, in every month except January and November; In May 

 they constitute more than one-fifth and in June one-seventh of the entire food. 

 The habit grackles have of following the plow to gather grubs is a matter of com- 

 mon observation which has been fully confirmed by stomach examinations. 

 Many stomachs were found literally crammed with grubs. 



Next in importance to beetles as an article of blackbird diet are the grass- 

 hoppers. — They constitute less than 1 percent of the total February food. — The 

 proportion of grasshoppers in the stomachs increases each month up to August 

 when it attains a maximum of 23.4 percent of all the food. After August the 

 grasshopper diet falls off, but even in November it still constitutes 9 percent of 

 the total for the month. The frequency with which these insects appear in the 

 stomachs, the great numbers found in single stomachs (often more than thirty), 

 and the fact that they are fed largely to the young, all point to the conclusion that 

 they are preferred as an article of food and are eagerly sought at all times. 



Caterpillars, including the army worm, averaged 2.3 percent in 

 each month, but in May a maximum of more than 8 percent is reached. 



A letter, from Benjamin J.Blincoe, tells of the bronzed grackle feeding 

 on the larvae of the sphinx moth which were infesting a tobacco field: 

 "A short time before sunset on the evening of July 21, 1932, while 

 Mrs. Blincoe and I were motoring along a country road near Dayton, 

 Ohio, we noticed a scattered flock of grackles, the individuals of which 

 were alighting in a tobacco patch and in the road ahead of us. Stop- 

 ping the car we soon saw dozens of the grackles alight in the road with 

 large green larvae of the sphinx moth, that is so troublesome to the 

 tobacco plant. Holding them securely in their mandibles, they beat 

 the fat larvae against the ground with such force that the impact 

 could actually be heard. We could also see many grackles picking the 

 larvae from the rather small tobacco plants. We counted at least a 

 hundred grackles with the larvae and I believe many more were help- 

 ing with the good work of ridding the plants of the destructive larvae." 



The Hymenoptera are represented mostly by ants, while flies are 

 entirely absent. Spiders and myriapods are eaten to a small extent 



