Caught in the act but is it a deuce? All waste comes out at once from the same orifice. Does not go number 1 or number 2 (deuce). Maybe it's a trey?
There's a urine component (white liquid) and a fecal component (black/dark solid matter). In raptors, nearly all excretions will have both, and will only lack the fecal when the bird hasn't eaten for a while, like 24 hrs or more.
TIL, thank you. Can see both components. What about owls who regurgitate pellets? Is the pellet just the indigestible bits and the rest excreted?