How Many Grackles Can Sit on the Birdfeeder?

While the actual numbers vary considerable day by day, the Colvin Run Habitat continues to have a steady set of blackbird visitors each day – grackles, cowbirds, red-winged blackbirds. As none of these birds were in the Habitat after mid-May last year, I suspect that they guys are part of a continuing migration north that will end in the next few weeks.
Grackles in the first photo: red-winged blackbird in the second.

The answer to the question? Seven grackles sitting on the birdfeeder. No other bird type seems to be that social or willing to tolerate that many fellow birds on the feeder.