Hullo Mitch, long time!
I have a small plastic pond and was wondering why the Goldfish were disappearing until I noticed a Grackle standing on the edge, ahhhh, never saw them catch one but when they moved on the fish quit flying away lol Also, in my little birdbath almost always the Grackles would soak a bit of corn or peanuts, not long but almost always. They are indeed very smart, used to not really like them all that much but now I look forward to them coming for a visit.
Watch them next time when more than one shows up. They do like your food, but they pay it back. They will work for food. When they first show up, they all land in the grass. Assuming you don't put down bug poisons and such, they will form a line and work along like a skirmish line, eating every bug in the grass, they even eat worms, just like a robin does, and then they go for your food. Starlings do the same thing. All summer long, my yard is bug free, while my neighbors always complain about mosquitos and gnats. HA. grackles and starlings are my secret weapon.




