Hi! New to forum, so please excuse any faux pas! I have never seen either of these birds, hence no photos, but have heard them many times (Sorry, no recordings)
1.) In the cool, moist western red cedar forests of Northeast Washington (intermountain region, around 1500 foot elevation, near the Canadian border, summer season, daytime), I often heard a bird that sounded just like someone going rapidly up and down one of those old wax pan flutes we would get as kids at halloween in the sixties, The call was somewhat hollow (echoes from the forest?), and would warble rapidly up-down-up-down-up-down-up (I may have thrown an extra in there, not sure). It only took a second or two, and the final up note was always a definite ending note. The scale was somewhere around three to four notes. I have tried to check calls of thrushes, warblers, wrens. etc without luck. Sound familiar to anyone?
2.) Just recently. Early spring, snows just leaving, Central Idaho (South of Stanley, ID), High elevation (7400 feet) lodgepole pine forest at the eastern foot of the Sawtooth Mountains, near a large meadow. Starting at dusk, and continuing through the night (I also heard them in the wee hours between 3 and 4 AM), In the very tops of the lodegpole pine trees. A series of four or so woops (woop woop woop woop), answered by others around the forest. There appeared to be quite a number of them, very active, most of them seemed to be in the tops of the trees near the meadow edge. I have camped here for years, and don't recall hearing them before, but the area has been hard hit by mountain pine beetle, killing large amounts of the lodgepole pine, so they may be here for the bugs, or congested in green patches that are left, I don't know. Any ideas? Thank you in advance for any ideas!