From Bingley’s British Quadrupeds.

Otters used once to be very common in England in the neighbourhood of rivers, and even in some instances of the sea, but in many places where they once lived in great numbers they have now ceased to exist. They destroy large quantities of fish, though they are so dainty that they only care for the upper parts of the body. If the rivers are frozen and no fish are to be had, they will eat poultry, or even lambs; and if these are not to be found, they can get on quite well for a long time on the bark of trees or on young branches.

Fierce though otters are when brought to bay, they can easily be tamed if they are caught young enough. More than a hundred years ago the monks of Autun, in France, found a baby otter only a few weeks old, and took it back to the convent, and fed it upon milk for nearly two months, when it was promoted to soup and fish and vegetables, the food of the good monks. It was not very sociable with strange animals, but it made great friends with a dog and cat who had known it from a baby, and they would play together half the day. At night it had a bed in one of the rooms, but in the day it always preferred a heap of straw when it was tired of running about. Curious to say, this otter was not at all fond of the water, and it was very seldom that it would go near a basin of water that was always carefully left near its bed. When it did, it was only to wash its face and front paws, after which it would go for a run in the court-yard, or curl itself to sleep in the sun. Indeed it seemed to have such an objection to water of all kinds, that the monks wondered whether it knew how to swim. So one day, when they were not so busy as usual, some of the brothers took it off to a good-sized pond, and waited to see what it would do. The otter smelt about cautiously for a little, and then, recognising that here was something it had seen before, ducked its head and wetted its feet as it did in the mornings. This did not satisfy the monks, who threw it right in, upon which it instantly swam to the other shore, and came round again to its friends.

All tame otters are not, however, as forgetful of the habits and manners of their race as this one was, and in some parts they have even been taught to fish for their masters instead of themselves. Careful directions are given for their proper teaching, and a great deal of patience is needful, because if an animal is once frightened or made angry, there is not much hope of training it afterwards. To begin with, it must be fed while it is very young on milk or soup, and when it gets older, on bread and the heads of fishes, and it must get its food from one person only, to whom it will soon get accustomed and attached. The next step is to have a sort of leather bag made, stuffed with wool and shaped like a fish, large enough for the animal to take in its mouth. Finally, he must wear a collar formed on the principle of a slip noose, which can tighten when a long string that is fastened to it, is pulled. This is, of course, to teach the otter to drop the fish after he has caught it.

The master then leads the otter slowly behind him, till by this means he has learned how to follow, and then he has to be made to understand the meanings of certain words and tones. So the man says to him, ‘Come here,’ and pulls the cord; and after this has been repeated several times, the otter gradually begins to connect the words with the action. Then the string is dropped, and the otter trots up obediently without it. After that, the sham fish is placed on the ground, and the collar, which seems rather like a horse’s bit, is pulled so as to force the mouth open, while the master exclaims ‘Take it!’ and when the otter is quite perfect in this (which most likely will not happen for a long time) the collar is loosened, and he is told to ‘drop it.’

Last of all, he is led down to a river with clear shallow water, where a small dead fish is thrown in. This he catches at once, and then the cord which has been fastened to his neck is gently pulled, and he gives up his prize to his master. Then live fish are put in instead of the dead one, and when they are killed, the otter is given the heads as a reward.

Of course some masters have a special talent for teaching these things, and some otters are specially apt pupils. This must have been the case with the otter belonging to a Mr. Campbell who lived near Inverness. It would sometimes catch eight or ten salmon in a day, and never attempted to eat them; while a man in Sweden, called Nilsson, and his family, lived entirely on the fish that was caught for them by their otter. When he is in his wild state, the otter lives in holes in the rocks, or among the roots of trees, though occasionally he has been known to burrow under ground, having his door in the water, and only a very tiny window opening landwards, so that he may not die of suffocation.