Its mostly likely a Juvenile Cooper's Hawk, they mainly eat birds. The juveniles in particular seem to be attracted to the commotion of a feeder. While full grown ducks are not usually targeted, they are at risk. Coopers are known to kill other big birds like chickens and pheasants. There was a recent special on Crows on PBS with researchers tagging crows with radio transmitters. Some of the transmitters ended up at the back in a Coopers nest. In the midwest, their favorite food is doves, but will eat anybird that visits your feeders. A couple of weeks ago, I saw one chase a finch and catch it after several figure eights through the trees. It was very impressive to see such a big bird chase a little bird and catch it.

Yep, Red-tailed Hawk. Dark head, pale breast, dark belly. -O-

That seems right. Thanks! It did look like a white bird when it was flying, so I was surprised at how blue-grey the one photo I managed to get turned out--white tailed kite would explain that.

I cannot really help on this one.May be a Sharp-shinned Hawk. Luc