Good afternoon - Last Friday 7/11/2019, while checking and cleaning nest boxes in central NY, we encountered a nest box with 3 live ~2week old nestlings, and one dead partially consumed nestling. The head, breast, sternum and all of the organs were missing. There was some blood in the body cavity, but was not coagulated. Our initial thought was predation by another raptor? Has anyone encountered this sort of scenario? I plan on uploading an image of the inside of the box soon.
Best and thank you!