Concord, Mass.
1910
Oct. 29
[October 29, 1910]

  Clear & cool with strong N.W. [northwest] wind. Country white with
hoar frost & surface of ground frozen, at sunrise.

Bronzed Grackles migrating

  About 9 A.M. a flock of Bronzed Grackles, containing, as
nearly as I could count them, approximately 40 birds, passed just 
above the tops of the tall elms in front of the barn and thence
due south as far as my eye could follow them. About fifteen
minutes later a second flock containing about 30 birds followed the
first at the same elevation, over the same trees, & in exactly the
same direction. There was no regular or general calling but only an
occasional low, throaty cuck unlike the usual flight call & softer.
Both flocks had nearly the same formation, moving in a broad, widely
extended front and very swiftly. Indeed the speed was nearly
if not quite double that usually maintained by Grackles during their
breeding season. Moreover the birds flew on a perfectly level plane
with incessant wing beats, not rising & falling in undulations,
with intermittent wing strokes as is their ordinary custom. I have 
no doubt that they were engaged in a protracted migratory flight.