Cliff or Cave Swallow photo quiz

[swampfox]

I wasn't entirely sure in what location this photo query should be posted but chose this one since it was being offered up for discussion.  Any way, the bird on the far left in the attached photo is a juvenile Barn Swallow and, to its immediate right, is a juvenile Cliff Swallow. But what is the juvenile swallow on the far right? Cliff? or Cave? I photographed this trio of juvenile swallows on a wire adjacent to the River Run West parking lot just below the spillway at Millwood Lake just over 2 years ago.

[kingbird]

Cave Swallow.

[swampfox]

Here are the responses that I received either privately or via listserv and discussion board:

One responder raised the possibility without going further.
I can't see the lower throat too well with the given posture of the bird but from what I can see, I would say Cave Swallow.

I would say it’s a cave swallow based on the lack sooty color on the auriculars. What I fuss about is the presence of buffy tips on the throats of very recently fledged Cliff Swallows. These buffy tips apparently wear off quickly as I only see them about now through July. If not wear, then the feather continues to grow out, becoming more sooty later on in August. I think that many people view this as a buff collar. It is interesting to see that your juv. Cave Swallow here, which appears recently fledged, has a cinnamon throat, not a buffy one. Buff tips are visible but they don’t dominate. The auriculars are generally always sooty to some extent in juv. Cliff which I do not see the bird in the photo below. As for the possibility of a hybrid, that would undeterminable even in the hand at this age.

Cliff Swallow. Throat is darker than the forehead and no dark auricular area.

Just the head by itself looks good for Cave Swallow to me, especially with that nice capped appearance. What bothers me a bit is what looks like black speckling on the upper breast, if that is indeed what I am seeing.

Cave Swallow clearly received more support than Cliff Swallow. What did I think? Well, when I spotted the bird, my initial thought was Cave Swallow. The more that I studied the photograph though the less certain that I became that it wasn't within the variation for juvenile Cliff Swallow. I questioned whether the "capped appearance" really stood out enough and wondered about the lack of any dusky smudge in the auriculars. However, what gave me the greatest discomfort was the reddish color of the throat which seemed to be a good match for the red in the juvenile Cliff Swallow immediately to the left in the photo. So, my decision, both initially and after this little quiz, was that the detail present in the single available photograph seems contradictory and I simply can't, with absolute certainty, assign an ID to one species or the other. So, the bird on the far right will forever remain a mystery as far as I'm concerned. I'd rather keep a probable good record out of the AAS database than to allow a bad one in.