[Maine-birds] Nelson's Sparrow, Eliot

I have been doing a river bird survey every couple weeks at the Dover-Eliot Bridge on the Salmon Falls River, and when I was there 2 weeks ago I heard a bird that was entirely new to me.  Unfortunately I was unable to identify it.  Today I was back there again and heard the same bird in the same place, and was determined to figure out what it was.  Although I never saw it, I made my way through the Peterson's birdsong CD, listening to all the families I suspected the bird might belong to, I finally found Nelson's Sparrow, which matches the habitat and secretive nature of what I was observing.

My only question is this: the recordings I have listened to sound exactly like what I heard, with one small missing element.  The one I heard made the same quiet "cheeeeeeee" sound from the recordings on Peterson and Allaboutbirds.com, but the bird I have heard mad a small noise at the end, almost like the drippy noise of a cowbird, which I can only describe as "doidle-ink".  Does that sound typical of a Nelson's Sparrow - "cheeeeeeeeeeeeeeee doidle-ink"?

Thanks

--
Jeff Normandin

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