Date: 10/23/18 7:30 am From: Gregory Hanisek via CTBirds <ctbirds...> Subject: [CT Birds] Cave vs Cliff
To emphasize the excellent points made by Stefan Martin today and yesterday, it's rather late for Cliff Swallow and somewhat early for Cave Swallow (which has been primarily a November arrival but with some recent records for late Oct). In other words either is possible, so you can't make any assumptions based on seeing the rump color. You've got to look at the underside (seeing both surfaces on flying birds isn't always easy).
On Cave Swallow you want to see the uniform buffy underparts from throat onto the breast with that color wrapping onto the "cheeks" and creating strong contrast with the dark cap. Cliff Swallow has a very dark throat and primarily white underparts. The forehead spot also is white on Cliffs we expect to see here. Also, as Stefan noted, when looking at underparts remember there are still some Barn Swallows around.
So try not to let your strong desire to see a Cave Swallow compromise the extra time it may take to confirm an ID.