At first, I thought we were under assault by somebody trying to break into the ammo point, but there was no one around. Standing up, I picked up my helmet liner to replace it and saw that there were three large, deep scratches in the helmet liner. Upon looking around the area further, I spotted a very large owl perched on one of the spotlight towers. My only assumption was that this owl had thought it had seen something edible in the shine of my helmet liner and had made a swipe at it.
Although I spotted the owl .. or one similar .. on several occasions later, it never hit at me again, probably determining that I was inedible.
Ryukyu flying fox (Yaeyama ookomori)