“It is in the habit of retiring to rest and spending the night in the reeds bordering ponds in unfrequented laces, as are the rest of our ‘Blackbirds.’  One of their roosting places is alluded to by my young friend Dr. THOMAS M. BREWER, of Boston, in a letter, as follows:–‘The four Cow Blackbirds which I obtained the last day you were with us, were shot in the marshes of Fresh Pond, by Mr. CHARLES E. WARE.  I went to the pond a day or two after, but was unable to procure any, as it was so late in the afternoon that they were all gone to roost in the reeds, and I could see them in thousands, nay, tens of thousands.  The rustling noise they made was truly deafening.’ ”

Reference Data:

The Birds of America, by John James Audubon, 1913, page 21