I rose early this morning to try to get recordings of the possible Pacific-slope Flycatcher in Gregory Canyon. I was hoping to get recordings of both the dawn song and the position note, and I thought I did, but upon examining the spectrograms of my recordings, it became clear that the bird singing the dawn song and the bird giving the position note were different individuals. Thus, I do not believe that I heard dawn song from the "interesting" bird this morning. However, I believe it can still be identified as a Cordilleran given the shape of its position note.
I have posted a fairly extensive discussion of the identification problem on my blog at http://earbirding.com/blog/archives/2996. It includes spectrograms and audio of the Gregory Canyon bird, as well as the position notes and dawn songs of typical (and some atypical) Pacific-slope and Cordilleran Flycatchers. Many thanks to Steve Mlodinow for his sharp ears and his conscientious reporting. The bird does indeed sound like a Pacific-slope -- in fact, while I have frequently heard a few Pacific-slope-like call notes from Cordillerans in Colorado over the years, this is the first bird I've heard that seems to give the Pacific-slope-like variant almost *all *the time. Ultimately, I think this bird provides strong evidence that Cordilleran and Pacific-slope Flycatchers are probably not separable with confidence in the field, even by ear -- although spectrograms should do the trick. Nathan Pieplow Boulder -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
