The Grackle is one of the most beautiful birds you will ever welcome into your yard. The feature that really makes them stunning to watch is their opalescence, a colorful sheen that reflects off of their feathers.
A large black bird, the Common Grackle can be up to 13 inches, making it one of the largest birds to visit your feeder. In keeping with its plumage, the Common Grackle has a black bill, as well as black legs. Its head is actually blue-black and rest of the body is more of a plum-black or bronzed. One of my bird books indicated that bronzed-backed and purple-backed birds are two different subspecies of Common Grackle. No other books make reference to this. I believe that bronzed is the most likely type to be found in New Jersey. The female resembles the male, being only slightly duller in color and slightly smaller in size.
In overall appearance I think that Common Grackles are actually very dinosaur-like. I think it has something to do with their eyes and the slope of their neck to their feet. They remind me of a Velociraptor. Very predatory. Their eyes are another startling feature. Unlike their feathers, their large yellow eyes are unnerving rather than beautiful. Apparently they are not born with yellow eyes. Young Common Grackles start out with brown eyes which grow more yellow as they age.
They have a varied diet that includes insects, seeds, invertebrates, eggs, nestlings, fish, small vertebrates, fruit, grain and nuts. They will gratefully partake at the seed or suet feeder. They also have strong muscles that help them to open their mouths with focus, a tool which they employ to pry open spaces and get at insects and other small prey.
The Common Grackle is present in New Jersey year-round, but is much more common in the summer than the winter. In the winter they are more likely to be found near farmland where they have an easier time finding food. Grackles often flock in large groups that can include up to 75 pairs. Their winter or migration flocks, which often include other species such as starlings and blackbirds, have been known to number in the tens of thousands.