During the October 2007 BFRO sponsored expedition to Arkansas, an interesting animal howl was recording by BFRO investigator Ron Boles. The recording is about 30 seconds long and begins with a long, human-produced howl. Not long after this first howl, an answering howl was recorded. It's a quick series of four short howls, apparently all from the same source, and each a little higher in frequency than the last.
This howl was originally announced and discussed on this BFRO discussion forum thread:
The recording is no longer available from its original source, so Ron has given permission for me to make it available, as an attachment, below.
Other interesting information about this recording includes preliminary spectrogram analysis posted in this album:
And further discussion at this BFRO discussion forum thread:
Attachments: 2007-10-04 Arkansas Lil' Mtn_ road - howls bionic ear.mp3