Common Grackle
The Common Grackle has a seasonal migration that is contained
within North America, as seen in this animated map from Project
FeedWatch. This map is an interpolated surface based on
biweekly reports of FeederWatchers. It shows positive sightings of
birds, with the darker green areas indicating more birds. Note the increase in
the number of birds in the southern U.S. through February and the
subsequent increase in the northern U.S. in March and April.