When it comes to dangerous North American animals, the most dangerous, of course, is the
Homo Sapien or man. But of the four legged variety, most will give you some kind of warning unless they are actively hunting you.
Active hunters may include the Cougar, wolf or bear. Generally none of these will hunt humans unless hunger, injury or territorial impules are at play. But your job is to be aware of noises around you.
Some animals will be much more aggressive when protecting their young. Pigs, Deer, Elk, and even smaller critters like raccoons and fox can be suddenly aggressive in this case.
One of the biggest problems is feral dogs. They naturally form packs (like their ancestors - wolves) and can quickly surround their prey. Identifying the lead or "Alpha" male and taking him out can frighten off the others.
Rule #1 is don't bother the wildlife.
Never chase after an animal or try to get close to it. You can provoke a startling swift defensive strike before they flee. Those sharp hooves on deer are no joke and antlers can kill you just as dead as a .45 ACP.
Rule #2 is, if you see animals with their young, stay away! If you must take a picture, use a zoom lens. A riled up momma pig is nothing to laugh at. It's worse when her male in-laws join in to roust the intruder.
It's amazing how many people can't seem to remember these simple rules when in the outdoors. Too many city dwellers raised on
Disney tales.
I've been lucky with my outdoor adventures. I had a cougar curious about what I was doing on
his road, changing motorcycle gloves. I spotted him just as I was donning the gloves, talked in even, flat tones to him and glanced at him about every 1-2 seconds. At 30ft away, he could have had me, but I think he was curious or waiting for me to leave.
While motorcycle camping near Yellowstone once, I got up just before dawn for nature's call. I'd just finished (fortunately) when I spotted a slow movement downwind in the gray light. My snubby Model 19 was in my hand back to the campsite. By the time I went 25 feet to camp I'd spotted three moving critters and my blood went cold when I realized they were wolves. When I reached my bike and put the key in it, the count was five and they were circling.
The solution was to turn on the radio and find someone talking. That confused them enough to allow me to walk to the tents of other riders and quietly alert them. Gratefully I could hear slides being racked in a few tents. Once a 2nd person appeared, the wolves seemed much more interested in quietly
leaving.
If you know there are dangerous critters in your woods or the area you are hiking, take prudent precautions. That means keeping your food sealed; using quick-releases on packs so you can drop them in a hurry; carry a large knife as a last ditch weapon and be armed with a sufficient caliber weapon.