In British Columbia, Canada there is a resort area, Whistler, with many black bears. Among the other attractions are paintball gun wars. They sound a horn to announce when the game begins. The bears take that as a dinner bell. They eat the paintballs, which were designed to appeal to wildlife as food so the humans would not have to clean them up. Kids playing paintball and bears peacefully coexist.
In the past, there were parks where people intentionally fed black bears. This did occasionally result in a mauling, but quite rarely, which was why the practice continued.
These same urban coyotes do commonly attack our dogs, cats, and other pets. In fact, our pets can be a significant part of their diet. Nevertheless, they know by instinct or otherwise that they should not attack human children.
Most predators live in environments where they can not simply eat anything that moves. If they did they would rapidly eat something poisonous or otherwise dangerous to eat and never reproduce. So it should not suprise us that preditors have evolved to be picky eaters.
In fact, the first vertebrate a mammalian predator is likely to eat is an amphibian and amphibians are poisonous. When I was a child the easiest vertebrate to catch was an amphibian, for example, a toad. I have had far more opportunities to catch a frog or a toad than a reptile, mammal, or bird. We see birds all the time, but they fly. Wild mammals, squirrels, are also seen all the time, but they run and climb trees. Lizards are pretty fast, and I have rarely seen snakes. Amphibians are reasonably common and relatively easy to catch. Amphibians are also normally poisonous to eat. We eat frog legs and not the rest of the frog in part because some of the other parts are poisonous. So the easiest vertebrate a predator can catch, and therefore the first vertebrate they would probably eat is poisonous.
This is not just coincidence. If it is slow and easy to catch how does it survive? One obvious answer is poison.
Beyond amphibians, there are other dangers: venomous snakes, spiders, scorpions, bees, hornets, and other poisonous invertebrates. Predators also have to be careful about porcupines, whose quills can work their way into the predator's flesh until they harm a vital organ and kill the predator. Even skunks could be dangerous to the predator. The stench might make it difficult to hunt until it wore off and by that time the predator could have died of hunger.
However, for those of you who do not live in the very far north, remember the predatory mammals near you live in a world where they must restrain themselves from hunting and eating everything that moves. They simply would not be able to survive and reproduce if they attacked things they did not know were safe to eat. So some restraint is naturally part of the survival kit that evolution has given them.
This allows us to make sense of statements like we are not their prey. This kind of statement is commonly made about predators, and the humans frequently think, what nonsense. Does the bear have a list, does he keep it in his pocket. Suppose the bear I am facing missed that day in school, or is illiterate and can not read. Many people feel that there is no reasonable reason why we should not be on their list of prey and that the idea that they will not hunt us is just fuzzy headed, wishful thinking.
When we realize that predatory mammals need to have a list in their heads or they could not survive then it is easier to take comfort in the fact that there are about a million predatory mammals of species that grow large enough to eat us but they kill and eat about one out every 100 million humans living in the United States and Canada each year.
I have another friend that is afraid to come out of her cabin at night for fear of bears. She had a close encounter with a black bear fleeing a hunter. She was not harmed, but it frightened her. How many Americans are partially imprisoned in their homes avoiding bears and other big predators?
Furthermore, how many Americans avoid enjoyable, relaxing, and healthy hikes because of a misplaced fear of these predators? How many Americans die of heart attacks as a result of that missed exercise?
Beyond this, there is the ecological issue. If we recognize that predators have to exercise restraint, that restraint is normal for them, then it will be easier to accept large predators in our environment. This may greatly enlarge the range that the predators can survive in, and reduce calls for their extermination.
When a predator kills a person, we often hear that they are just acting naturally. Natural or not, it is not normal for mammalian predators to hunt, kill, and eat humans. Mammal predators are probably forgoing a billion or more opportunities to eat a human in the United States and Canada for every time that they actually kill and eat a human. The claim that the animal is normal is a dangerous slander of their species.
If we quickly kill the very rare exception, we can live peacefully with the vast majority. Even if we kill ten every time they kill one of us, just to be sure we get the one that ate a human, this would only mean killing thirty or forty predators every year out of about a million. This will not significantly impact on these species.
It has been suggested that we wear bells when we are in bear country, so the bears will hear us and avoid us. This has lead to jokes about the bells being dinner bells. Another joke asks, how to tell good bears from bad bears. Answer: bad bears have bells in their poop. This is a good joke, and what's more an effective argument for not wearing bells.
But suppose we think of a bell as similar to a rattle snake's rattle. Animals that are poisonous call attention to themselves to warn the predators to stay away. Humans are functionally poisonous from the predator's point of view. If the predator kills us, the other humans will hunt the predator down and kill it.
Similarly, it has been suggested that we carry an umbrella and open it when we see a predator so we look bigger. As a teen or young adult, I was at a camp and talked to a farmers wife from a neighboring farm. A mountain lion had just attacked their horse. Even with an umbrella, I wouldn't have looked as big as the horse. Perhaps, however, the opening the umbrella would simply make you look weird. The predator might be thinking, mother never taught us to eat those things with umbrellas, maybe they are poisonous.
Note that the puffer fish, by blowing itself up is following something like the umbrella strategy, and puffers are highly toxic. I believe it is commonly thought that puffers are trying to become big so they will not be eaten. Perhaps puffers are trying to be weird to warn predators of their poison, just as poison arrow frogs warn predators with their bright colors, and rattlesnakes warn predators with their rattles.
Part of the reason that this works is that a total bluff would not work. If an animal that was not poisonous or otherwise dangerous, and was easily distinguished from animals that were poisonous or otherwise dangerous tried to bluff, eventually the predators would call their bluff. They would be quickly slaughtered and probably be driven into extinction.
Note that animals that look similar to animals that are poisonous are not completely bluffing either. The predator that calls their bluff better be able to distinguish between them and the poisonous look alike or the predator is likely to eat the wrong one and die before they reproduce.
So we can see that there are practical applications to the idea. Perhaps there are practical applications for you, or people you know. For example, my friend who is living in a cabin in the woods said that this message reassured her. It might help your friends if you would refer them to this page, and of course, I welcome referrals and links.
But much of what I have written about North American land-dwelling mammals applies more generally. Most animals large and strong enough to eat people through the land areas and even in the sea refrain from eating us. The Nile and saltwater crocodiles are perhaps the biggest exceptions. The point I have made about poison is generally applicable to most environments, the arctic land environment being the big exception and applies to mammals, reptiles, and fish.
Of course, many of the reptiles and fish are not raised by mothers and thus have to get their list some other way. In many cases, the fish and other animals at sea may think the way we swim and everything else about us are so weird that it is best to be wary. Weird, somewhat awkward, slow-moving animals tend to be poisonous. If you haven't eaten it before, it is best not to take a chance, at least until after you have seen another predator eat it. Could this be a source of the famous shark feeding frenzy phenomena? The sharks are wary until one starts to feed, then they take that as a signal that the prey is not poisonous. I have a more extensive treatment of the sharks, feeding frenzies, and blood in the water here.
The case of the big crocodiles may be very different from that of fish in the sea. The Nile and the saltwater crocodile may see us as just another mammal coming to the waters edge. From their point of view we are not big enough, like an elephant, a hypothalamus, or a rhinoceros, to be dangerous. Almost everything that walks on long legs under its body is reasonably safe to eat. So our difficulty with the crocodiles may be that we seem similar to them to what they have learned is safe prey. The two crocodilians that are the most dangerous are the largest. Smaller crocodilians tend to leave humans alone. They are perhaps more focused on fish as prey.
But my speculation at this point is getting a bit sketchy, perhaps I should leave a few mysteries to be solved by the trained biologists.