Bronzed Grackle; Common Grackle (Bronzed)

Take a look at the link. It should help. :)

I think it may be a Common Grackle. It would also fit the subspecies "Bronzed Grackle". I don't believe the Rusty Blackbird has the bronze tint to it. I will try to find a reference for the subspecies for you. I have it in my National Geographic Field Guide to the Birds of North America.

Looks similar to the female Common Grackle but the Rusty has a thinner bill.

Rusty Blackbird is one of North America’s most rapidly declining species. The population has plunged an estimated 85-99 percent over the past forty years and scientists are completely puzzled as to what is the cause.

Nice spotting!