The last two evenings from about 6:55 to 7:25pm I've watched a
continuous stream of black birds flying low overhead southward along the
Lemon Fair River lowlands toward the river's extensive flooded lands
west of West Street in Cornwall. I assume, but do not know, that there
is a temporary night rookery there, perhaps in a tract of floodplain
forest on the west side of the lowlands in Bridport.
The streams each evening consisted of flock after flock ranging from
10-15 birds to 60-80 birds per flock. Three to five flocks passed by
per minute. My crude best estimates made from adding up the flocks
yielded a count of at least 3000 birds, and possibly several hundred more.
The birds were well silhouetted against the twilight sky, and as the
birds were flying just above the treetops they were easy to scan with
binocs. The vast majority were Common Grackles. Well interspersed were
birds that appeared to be Red-winged Blackbirds or perhaps even Rusty
Blackbirds. I would not have been able to distinguish Cowbirds. I did
see a very few Starlings. And trailing one group of grackles there was
one cluster of four birds with the body shape of Woodcocks and the
flight paths of inebriated bumblebees.
The birds were almost entirely silent, with only exceedingly scarce,
isolated "kek"s. Both nights the streams ended quite abruptly, after
which I never saw even a single straggler.
Southern end of Snake Mountain, Cornwall