DELAWARE VALLEY ORNITHOLOGICAL CLUB. 15 



Evidently the entire roost had gone elsewhere, and as 1 do not 

 recall seeing any flights in late August of former years, this 

 change may be a regular feature of the life-cycle of the species. 

 I heard of no attempt to drive the birds from their roost at the 

 Asylum, and there was no apparent disturbing cause." 



Three interesting facts are brought out by these observations: 

 first, that the line of flight follows the same course and the same 

 direction each evening for several weeks of every year; second, 

 that the Asylum trees are also nesting sites for some Grackles; 

 third, tliat this roost was abandoned this year and is probably 

 abandoned every year long before the southern migration 

 begins, and has therefore not the same status as the roosts at 

 Germantown and Overbrook, which are occupied the year round. 



Following out these lines of thought, it was noted that the 

 directions of the flight-lines are permanent for each roost. At 

 Swarthmore, Pa., Mr. Palmer states, the birds arrive from the 

 south and southwest; at Germantown they come from the 

 northwest, north, northeast, and east; at Olney, N. J., Mr. 

 Morris reports, they come from the southeast; and at Woodbury, 

 N. J., they appear from the northeast. To all these roosts a 

 few individuals come in from all directions, but the large flocks 

 follow the main flight-lines. 



In regard to the second fact, observations of the members 

 seems to suggest that in the beginning most of the roosts were 

 nesting colonies, but as each wood was occupied by more and 

 more roosting birds, the nesting Grackles abandoned it for 

 quieter quarters. This was the case of the Germantown roost, 

 which was originally the scene of much nesting activity, but 

 now holds not more than a dozen nests each spring. 



That several of the roosts are not permanent for the whole 

 year and that others are merely gathering-places for each after- 

 noon is evident from the various reports. The Kirkbride roost 

 was deserted by the first of August. At Kennett Square Mr. 

 Pennock reports a woods, to which the males retired during the 

 breeding season and which was not occupied as a permanent 

 roost. The author, while hunting for a permanent roost in 

 Camden County, N. J., came across several gathering-places- 

 and at least one of these transient roosts. 



