This rant is a little more specialized than the others, and will go by types of animals rather than just general mistakes. I actually think animals can be used in fantasy much more often than they are, but I won’t try to cover every single instance of every animal, just the most common.
1. Cats are unlikely to be pets in most places.
This is because most of the people in medieval-like societies can’t afford animals that do nothing to earn their keep. Nobles are probably able to have pampered pet cats and the servants to feed and brush them, but people of the lower classes can’t give food away to a cute little stray kitten just because. Cats in our own Middle Ages were usually ratters (and often feared as witches’ familiars, and tortured and burned). If a house or business has no problem with rats, mice, or birds, why would they tolerate a cat hanging around and taking food?
Similarly, cats are unlikely to be completely tame unless they’re those pampered pets. Cats are not pack animals and can rarely be trained to do tricks. Also, if the history of your fantasy world echoes our own at all, cats will have been domesticated for a much shorter time than dogs (about five thousand years for cats in our own world, as compared to twelve thousand or more for dogs). All of this leads up to cats in fantasy realistically being much more scruffy, less tame, and more tolerated only for practical purposes than in our own world.
2. Dogs will not come in the variety of breeds that our own world has.
This may seem obvious, but little yappy dogs that are the pets of some disgusting noble lady are very common in fantasy. How did they get there, though? It takes generations of selective breeding to diversify dog breeds, and while people in fantasy might be interested in such things to make better guard dogs and herd dogs, they don’t appear to know the principles involved in it most of the time. (Any fantasy world that knows the principles of evolution just because has some explaining to do). So little yappy dogs should either be part of a noble society that has long been established, where people would have the time to give thought to such luxuries, or imports from a country which can afford the breeding—or not there. The same thing applies to dogs as cats and most other animals: if they don’t have a practical purpose and there’s no explanation, they shouldn’t be there.
3. Consider the realities of having horses walking through your cities.
I said a lot about horses in the rant on death and battle, which I won’t repeat here. But one thing that I forgot to mention was accommodation for horses in cities. What happens to all the horseshit, for one thing? Are there people who go around cleaning it up, or do your heroes ride the Amazing Mechanical Horses that don’t eat or defecate?
For another, cities are not the ideal environments for horses. Fantasy stories where riders just gallop their horses down any alley or sidestreet make me laugh. How can they fit between buildings and make so many sharp turns? How do the horses keep their feet in the excrement and trash likely to be scattered in so many alleys? How come the horses are never exhausted by the chase? It might be amusing to read about heroes who actually have to cope with the consequences of such things, such as getting dumped in the mud when they grandly try to gallop their horses between buildings.
Finally, horses will have trouble keeping their hooves in some cities. Packed dirt roads are fine. Mud is trickier. Cobbles can be very tricky, and ice and snow trickier still. Consider what it will do to a horse’s feet when your heroes are riding them through such terrain. Blacksmiths don’t exist just to adopt royal heroes; they have real work to do in a society that depends so much on horses.
4. Carrier pigeons are not infallible.
This applies to other birds that carry messages, too, whether they’re owls or ravens. At least some of those messages won’t make it to their destinations. This applies especially to a city in times of warfare, where the enemy will probably merrily shoot the birds they see fluttering over the walls. At best, they’ll capture the other side’s messages; at the worst, they’ll get some good food out of the deal. And if your heroes are using birds like pigeons that are the natural prey of other animals, then at least some of them won’t deliver their messages through pure chance. No message system that depends on birds should be foolproof.
5. Your heroes are not going to be familiar with every animal that exists.
This might seem obvious, too, but I’ve lost count of the number of times I’ve read something like “He had a neck as long as a giraffe’s” thought by a hero who lives in the temperate forest-and-field environment so beloved of most fantasies. How does your hero know about giraffes? He might, possibly, have seen one in a traveling circus if your world has such things, or in a zoo if his society is wealthy enough to afford one. Outside those circumstances, though, it’s best to restrict someone’s familiarity with animals to what they would reasonably know about from having lived in their home village all their lives (the situation of a lot of heroes and heroines in fantasy).
6. Wolves are not fierce ravening creatures. Nor are cougars or bears.
It might be different if you’re dealing with werecreatures or animals turned evil under the control of a mage, but these animals are generally shy and avoid humans. The only exceptions are during lean winters when the hunger is at its peak—and even then, they’re far more likely to attack livestock than humans—and when the animals have been provoked, such as a cougar wounded by a hunter or a mother wolf defending her young. If your main characters are part of a farming community and fear wolves because of stories they’ve been told, that would make sense according to the storyline. It would not make sense for wolves to attack your character who was traveling inoffensively through the woods in summertime just because you want an exciting encounter. The most they might do is come and inspect the fire.
7. To take the flip side of the coin, it’s damn hard to tame wild animals.
Too many amateur fantasy authors have apparently read “Androcles and the Lion” too many times, and think that if their character pulls a thorn from a wild animal’s paw and then sees the animal again, the animal will follow them around like a dog. Wrong. The animal is much more likely to run away. Even wild animals who have spent decades in captivity, or been born there, can turn on their trainers if they are hungry, angry, or in pain, or if the humans make a mistake. Wild animals in captivity are actually more dangerous than ordinary ones in the wilderness, because they’ve lost their natural fear of humans.
If you really want your character to have a tame wolf, then he or she would have to dedicate themselves to the task, and ideally take a pup from a den before its eyes are open. The wolf is much more likely to accept the character as the alpha of the pack that way. Adult wolves should never be easy to tame, and probably never completely tame.
8. Prey animals have keener senses of sound and scent than their human hunters.
There is no way that someone can just march up on a deer and shoot it, particularly if he or she has never done it before. Deer, rabbits, and the like are always on the watch, and in a group will have a sentry. Your hunter will have to consider smell and sound as well as sight, and attempt to approach silently and when the wind isn’t blowing his scent to the animals. The best ways to do this are to set up a blind somewhere where the prey animals regularly pass and stay there motionless for hours—which takes time—or to approach when the animal is in a vulnerable position, such as by a stream. (The sound of the water will cover the hunter’s movements if it’s loud enough, and the scent of the water helps confuse the drinking animal). Even that can be spoiled if the wind shifts.
In other words: Hunting shouldn’t be effortless.
Given how many fantasy societies are patterned on medieval ones, and how much animals were an integral part of the medieval world, it’s amazing how little attention is paid to them.