Never forget being on a field problem once on a moonless night. We're in the middle of bum-fiddle and suddenly we hear the most unusual gutteral, moan-growl noise you ever heard coming out of the bush about 30 feet off somewhere. The old man was next to me (he was a city-slicker) and said "Sgt. B. what kind of animal is that???
Although I had spent most of my life out in the sticks I had to tell him I didn't have a clue. I put a magazine in and slid the selector to rock-n-roll. It was freaking hilarious how fast the rest of the guys locked and loaded. You never saw a platoon un-a** an AO as fast as we did that night. Still don't know what kind of critter it was or what made it make that funky sound.
Probably a mountain lion or bobcat. They can both make some ungodly sounds.
I remember being on a camping trip in Arizona one night, and we must have camped too close to the animal's favorite spring or something, because it circled the camp for an hour. Every five minutes or so we heard what sounded like an opera singer being garroted. What was really freaky was how it always seemed to come from behind us, no matter where we were looking. Found the tracks in the morning, it was a mountain lion. I slept with my Buck knife open under my pillow.
It's amazing how the old caveman instincts surface in that kind of situation.
-ccm