I went to Lilypons yesterday for the first time in a year or so.  Saw 
both White-throated and White-crowned Sparrows, also Swamps Sparrows, 
but nothing very surprising.  I heard one song/call that puzzled me - 
several series of fairly loud peeps at a rate of several per second, 
without much change in pitch.  They weren't raspy or raucous.  Last 
evening, I went through all the bird songs on Thayer BNA after 
(ornithologically) the vultures, and the only one that sounded similar 
to what I heard was Pygmy Nuthatch, which seems very unlikely.  Of 
course, for many species the Thayer software has only songs, without calls.

Is there something reasonably expected to be here that makes such a sound?

Thanks,
	Bob Hartman
	Colesville, MD