Greetings,

After my sighting of hundreds of grackles flying northeast over East 
Silver Spring (coming from DC or Potomac River), in mid-August and 
having two occasions of 30 or more grackles at my feeder, the number of 
sightings have dwindled to nearly zero.  I had thought I was seeing a 
mix of Boat Tailed Grackles and Common Grackles but  I have changed my 
mind after more research.  My Natl. Geographic Bird book lists only one 
size for these with the BT Grackle being 2 inches longer than the common 
grackle.  They also show the BT as being more iridescent.  This is 
correct but they did not give me the full information that the darker 
male Common Grackle is 10 to 12% larger than the more brownish female.  
If that translates to length of the bird, then the approx. 2 inch 
difference in size I was seeing was only the difference between the 
adult male and female common grackle.

More work with Google, indicates that common grackles in New Jersy form 
large roosts in late summer with the peak roost size being in 
mid-August.  Roost populations range from 2000 to 10,000 individuals!  I 
think the groups of common grackles I was seeing were headed for a roost 
site.  Is there any information as to where in Maryland these common 
grackles roost?  I have noticed that fewer and fewer members are 
reporting seeing any common grackles.  I had only a pair in my backyard 
for the first 2 weeks of Sept. and now they are gone.

I understand that the migration south does not occur until well into 
October or early Nov.  So where are they?  Somebody must have way too many!

George Lane
Silver Spring  Montg. Co.

PS  My next puzzle deals with European Starlings.  In the early morning 
hours (sunrise), I am seeing flocks of starlings numbering from 20 to 40 
or more birds flying South East over Silver Spring.  I have seen as many 
as 3 flocks at the same time and this goes on for 20 to 30 minutes that 
I am watching.