USA MA NE
I have a bird / animal coming to the trees in the backyard making this call (see link to audio file), which does not really sound like a bird - it's fairly low frequency. I have not seen it. Sometimes it sits in a young tree, where you can almost see through to the trunk. But I cannot make it out, so it's not very big (like a turkey). It comes at late afternoon and stays around until ~11PM. It switches trees fairly quickly, so I assume it can fly. The call is always the same. Sometimes another one of its kind answers.
You don't need dropbox. Ignore "suspicious link". Close login popup. Click download arrow. Direct download.
I added a Soundcloud link: