Unfortunately no recording, but heard a call I'm unfamiliar with today. I'm near-certain it's some kind of owl but I can't find any recording of one that sounded like this did. About 8am, mature woodland bordering on open fields, middle of Shropshire. Came from high up in canopy. A repeating, alternating-in-pitch series of 6-8 muffled hoots (not at all dissimilar to that weird wobble-board instrument Rolf Harris played). Didn't carry far and it almost sounded as though they were hoots that never really got out, like burping with your mouth shut. Pace similar to Great Tit's distinctive "tea-cher" (and pitch variance about as similar) call but ending after 6-8 notes. Among owls I've heard, closest is Short-Eared, but slower pace and alternating in pitch, not rising increasingly. Any clues? I've been through all kinds of birds, drumming Snipe, Woodcock, fowl, etc, and nothing I've heard resembles what I heard.