This was a real treat yesterday at Frontera Audubon as I have never seen a Black-billed Cuckoo before. It certainly behaved like the Yellow-billed Cuckoos I have seen, secretively staying at least partially obscured in the tree. It's red eye ring is barely visible but the black bill is best seen in the middle pic.
I added the crummy pic below only because it does show the white spots on this species graduated tail. SeEtta