The white blocks on the underside of the wings are not always that obvious, either. If the light is right they will appear all black. Black vultures are similar to turkey vultures but the tail is shorter and they are smaller, and if my steel trap memory (har har) serves me correctly they are much more aggressive. But I will have to go back and check on your location to know if you would even have blacks..... Seeing groups of 15 or more tvs is not a big thing here where we live, but recently while on a trip to Texas we spotted a real spectacle: a huge "stack" of tvs rising up on a thermal in the late morning. I could not count them all but there were easily over a hundred birds in that flock. Must have been a dead cow or something to draw that many birds in!!!

Its sounds like you probably have a pair of Red tails and probably a sharpie or Coopers Hawk. In general, Hawks don't prey on other healthy adult Hawks. Larger Hawks will attack the nests of smaller hawks. About the only exception is probably a large Goshawk would have smaller Hawks on the menu and be able to catch them. But in your case, a Red tail trying to catch a Sharpie is like a Suburban trying to catch a Corvette. In one of the few studies I've seen, the highest Sharpie mortality was from owl predation, which leads them to roost in dense cover. Your probably just seeing an increase in raptor activity as Hawks begin pairing up and will start nesting in a few weeks.

Always a treat to hear about your 'babies', Caroline. We're on round three of Cardinals -- if the young ones a-courtin' now lay eggs. We have mature arbor vitae around two sides of our lot -- and some privit that they seem to favor. I was drawn to the creek last week by calling between a pair of (I think?) Flickers and their four 'kids'. (Whistling cries; spotted breasts; red 'gorgets' on their necks.) They were searching for insects on tree trunks -- and probably finding plenty of emerald ash borers. We have some big tree removal bills coming up!

Helmut Schmidt: The biggest room in the world is the room for improvement.