1160 REPORT OF STATE GEOLOGIST. 



November 11, 1889. Their remaining through the winter depends 

 not so much upon the weather as upon a supply of food that may be 

 easily obtained. 



They gather into large roosts some winters. There was one re- 

 ported the winter of 1896-7 in Brown County. Considerable attention 

 has been given in different parts of the country to the food of the 

 Robin. I can give but a few points from the conclusions reached. 

 From the time of its first arrival until June, almost its entire food is 

 insects. In the early spring in Illinois, Prof. Forbes found its chief 

 food was the larvae of a fly (Bibio albipennis Say,), a species which if 

 allowed to increase might do much damage to meadows and pastures. 

 Mr. Wilcox has found this to be the same in Ohio and doubtless it is 

 true in Indiana. The last name<J gentleman has found that over 96 

 per cent, of their food in- April, 97 per cent, in May, over 43 per cent. 

 in June, was insects, of which from almost one-fifth to near two-fifths 

 of the total food was injurious species and more than that of neutral 

 species. In June they began eating fruit to an amount equal to 54 

 per cent, of their food, cherries forming 14.6 per cent, and raspberries 

 36.6 per cent. Prof. Forbes found, deducting the Bibio larva?, that 

 the total percentage of injurious insects eaten was as follows: February, 

 18; March, 37; April, 39; May, 55; June, 24; July, 10; August, 31; 

 September, 7, while the percentage of fruits and seeds eaten were 

 for June (when they first became important), 58; July, 79; August, 

 56; September, 70, and October, 56. In June cherries formed 47 

 per cent, and raspberries 8; in July, blackberries were 56 and currants 

 17 per cent.; in August, cherries were 44 and hackberries 5 per cent,; 

 in September grapes were 52 and Mountain Ash berries 8 per cent.; 

 and in October grapes constituted 53 per cent, of their food. 



The grapes eaten in October and doubtless many of those eaten in 

 September were wild kinds. In an orchard infested with canker- 

 worms the Robins' food consisted of 40 per cent, of that species (Kept. 

 Mich. Plort. Soc., 1881, p. 204). 



Profs. F. and L. Beal have reported an examination of 330 stcfcnachs 

 of Robins taken at different seasons. Forty-two per cent, of their 

 food was found to be animal matter, principally insects, and the re- 

 mainder is largely small fruits and berries. 



From the evidence presented it is safe to say that noxious insects 

 comprise more than one-third of the Robin's food. Vegetable food 

 was found to be nearly 58 per cent, of that eaten, wild fruits forming 

 47, and varieties that were possibly cultivated a little more than 4 

 per cent. They ate 25 per cent, of cultivated fruit in June and July. 

 Wild fruit was eaten every month and forty-one kinds were noted. 



