54 Bulletin. No. ij. 



A more exact method would have been to secure birds and study the 

 plumage, but this would have thwarted study of the roosting habits by 

 driving the birds away. It was the roosting habits and not the molt that 

 I wished to study at that time ; the other could wait. The first feathers 

 found were the innermost primary and outermost greater wing-covert, 

 both at the same time. The contour feathers could not be definitely 

 located, and so were passed by. The primaries were molted in regular 

 order from the innermost outward and the greater coverts from the outer- 

 most inward, followed by the secondaries from the outermost inward, 

 except that many secondaries were found before any of the first and 

 second primaries. This is practically the order determined by Mr. Wit- 

 mer Stone for the genus Quiscalus* But the subject of molting will be 

 fully discussed in a subsequent Bulletin, and so need not be further 

 treated here. In 1894 and 1895 the desertion of the roost was coincident 

 with the completion of the molt. It would probably have proved the 

 same in 1896 if the birds had not been driven away before the usual time. 

 The beginning of the molt so soon after occupying the roost and the de- 

 sertion of the roost as soon as the molt is completed make an irresistable 

 argument in favor of the supposition that the molt is directly responible 

 for the formation of the roost. This is suggested by Mr. F. E. L. Beal 

 in his pamphlet, Some Common Birds in Their Relation to Agriculture, 

 page 25, in which he says : " After July it [the Bronzed Grackle] becomes 

 very rare, or entirely disappears, owing to the fact that it collects in large 

 flocks and retires to some quiet place, where food is abundant and where 

 it can remain undisturbed during the molting season, but in the latter 

 days of August and throughout September it usually reappears in im- 

 mense numbers before moving south." It is true that the Oberlin grackles 

 are not nearly so much in evidence while molting as while nesting, and 

 are rather more abundant after dispersing from the summer roost, but 

 their choice for roosting is anything but a quiet place. Instead of feed- 

 ing near their roosting place, they wander miles away before ceasing 

 their flight. A better designation for our grackles would be, ' ' Locally rare 

 or absent during the molting season," for surely they are numerous 

 enough in many places at certain times of the day. 



While there are many things in common between the grackle's and the 

 robin's roosting habits, there are also some differences. Mr. Brewster's 

 excellent account of the "Summer Robin Roosts" near Cambridge, 

 Mass., already referred to, and my own notes on this Oberlin Summer 

 Grackle Roost form the basis for this passing comparison. 



*Thc Molting of Birds with Special Reference to the Plumage of the Smaller Land 

 Birds of Eastern North America. Witmer Stone. 



