Pigeons have a sensitive sense of smell. They hate strong scents like peppermint, cinnamon, or garlic. Mix a few drops of peppermint oil with water in a spray bottle. Spritz their favorite ledges.
Warning: your garden will smell like a Christmas candy factory. But hey, at least it’s festive!
Alternatively, sprinkle cayenne pepper or chili powder where they land. They’ll taste it and gag. It doesn’t hurt them—it just ruins their mood.