Deer/Elk/etc.: Rifle and butt-cuff loaded, usually one spare ammo carrier in Camelback (about 20 rds total), sidearm (.357 or .44) with full cylinder plus one speedloader or speedstrip.
Boar: Rifle and butt-cuff loaded, spare ammo carrier on belt, plus spare box of 20 rds in Camelback (about 40 rds total), full sidearm plus two reloads (magazine, speedloader, speedstrip, whatever). Haven't run out yet, but have come close. Hunt with H&H Hunter and you'll need all the ammo you can carry. Pig-a-palooza! Nothing like a running gun battle with 20 or so hogs to burn up lots of ammo.
Fishing in Alaska: .44 loaded plus 2 speedloaders, plus 18 extra rounds sealed in plastic in Camelback. When carrying shotgun, Brenneke slugs fully loaded (2 or 7, depending on whether SBS or Pump) plus full butt-cuff, plus spare box sealed in plastic and in dry bag/box.
Hunting in Dangerous Game areas in Africa, Rifle and butt-cuff fully loaded, culling belt w/20 rounds (31 rds total), spare box of ammo in my pack (stays on hunting truck).
Yes, I carry a lot of ammo. Ammo is used for primary game hunted, secondary game (rabbits, squirrels, badgers, coyotes, etc.), signaling, fire starting and self-defense.
If you are forced to use a firearm for signaling, don't expect it to be heard or have someone respond on the first try. Do you know how many people in the field actually KNOW the cadence for signaling with a firearm? How many will respond to it when they hear it out of the blue? Trust me on this, you may be signaling for a while before you get someone to notice, no matter how many people actually hear it.