The tinnitus had subsided to the usual level when I got up last night. (Touch wood.) Went outside with Bear while preparing my lunch/dinner to take to work - he's too short-legged to trigger the motion-sensor light and has become reluctant to go out there at night alone. The light flicked on - revealing a large rabbit on the lawn 3 feet away from Bear. A grand chase and search took place, and I finally had to put a hand on his collar to get him to come inside so I could finish getting ready for work. But that's the real solution to the mystery of the circular depressions in the long grass, I think.
.