on 7/6/06 3:10 PM, Gerald & Laura Tarbell at  wrote:

>   I mentioned this a few weeks ago and Bob Ringler said he was sure it was
> a vocalization. We have discussed it some since and so far he still hasn't
> convinced me. The best evidence he could produce is Bent's reference to
> Brewster (1882) who said
> "They had another note also which was much like the whistling of wings. I
> afterwards satisfied myself that this sound was a vocal one."

I cannot cite any journal articles for this behavior, but I can now relate a
personal observation. Yesterday, I was birding with a group when I saw and
heard an Acadian Flycatcher doing the "flutter call."

As I had just read your post, I called the group's attention to the behavior
and told them about the issue you had raised. We all watched and listened to
the bird as it fluttered from perch to perch, making the call as it did so.

More than once, I observed that the call continued briefly after the bird
had landed on its new perch and its wings were folded and not moving. The
continuation was very brief indeed, but definite enough to make clear that
the "sound was a vocal one."

My observation was also confirmed by the other members of the group.

Elliot

-- 
Elliot Kirschbaum
Shepherdstown, WV
kingfisher500 at adelphia dot net