This is the Common Grackle (Quiscalus quiscula) displaying to a female and perched rather unceremoniously on a water-level marker near the lake. Common and widespread in Eastern North America, nesting in trees, especially dense evergreens. Forages for seeds and invertebrates on the ground near trees. Often seen in very large flocks. Harsh unmusical voice and very active in chasing the Red-tailed Hawk from their territory! Sadly I never managed to get a picture of that!!
Settings: F/5.6 1/2000sec AV -1EV ISO250 @700mm tripod
Many thanks for your C&Cs on my Catbird upload - really appreciated