Preliminary Report on Roosting Habits of the 

 Purple Grackle in the Delaware Valley 



BY JULIAN K. POTTER 



On August 1, 1912, Mr. Stone sent out a circular letter to the 

 migration corps of the D. V. 0. C, asking the following ques- 

 tions concerning the roosting habits of the Purple Grackle r 



If there is a regular evening flight near your home, 



(1) How long does it take to pass? Does the time of flight 

 change as the season advances ? How many birds pass ? 



(2) Where do the birds roost ? Where do they feed ? Where 

 does the flight start ? 



(3) When do they abandon the roost? Do they change 

 their roosting place or feeding ground as the season advances ? 



Papers on the subject were received from ten observers: W. 

 L. Baily, E. C. Emlen, Russell Mason, George Spencer Morris,, 

 S. C. Palmer, C. J. Pennock, J. K. Potter, S. N. Rhoads, 

 Witmer Stone and K. R. Styer, 



It being the purpose of this report to deal only with the fore- 

 going questions, much interesting data taking up other phases 

 of Grackle life could not be considered. 



As soon as they arrive in the spring the Grackles gather at a 

 definite roosting place, generally one occupied for a number of 

 years. Already they find at this roost a few birds which have 

 spent the winter there. Mr. C. J. Peck ' and Mr. E. C. Emlen * 

 have shown that these main roosts are practically permanent 

 the year round, being deserted completely only for a few days 

 during severe weather in January and December. During 

 March the roosts fill up and the number of birds reaches large 

 proportions, but in April and May the roosts are almost de- 

 serted again, while the Grackles are busy with courtship and 



^The Overbrook Grackle Roost, Cassinia, 1905, p. 36. 

 ' Notes on the Germantown Grackle Roost, Cassinia. 1902, p. 22. 



(12) 



