IV
THE MOST INTELLIGENT ANIMALS
To the professional animal-man, year in and year out comes the eternal question, "Which are the most intelligent animals?"
The question is entirely legitimate. What animals are the best exponents of animal intelligence?
It seems to me that the numerous factors involved, and the comparisons that must be made, can best be expressed in figures. Opinions that are based upon only one or two sets of facts are not worth much. There are about ten factors to be taken into account and appraised separately.
In order to express many opinions in a small amount of space, we submit a table of estimates and summaries, covering a few mammalian species that are representative of many. But, try as they will, it is not likely that any two animal men will set down the same estimates. It all depends upon the wealth or the poverty of first-hand, eye-witness evidence. When we enter the field of evidence that must stand in quotation marks, we cease to know where we will come out. We desire to state that nearly all of the figures in the attached table of estimates are based upon the author's own observations, made during a period of more than forty years of ups and downs with wild animals. ESTIMATES OF THE COMPARATIVE INTELLIGENCE AND ABILITY OF CERTAIN CONSPICUOUS WILD ANIMALS, BASED UPON KNOWN PERFORMANCES, OR THE ABSENCE OF THEM. [Footnote: To the author, correspondence regarding the reasons for these estimates is impossible.]
[beginning of chart]
Perfection in all=100 [list of categories below are written vertically above the columns, with the last column unnamed and representing a total score of animal intelligence/1000]
Hereditary Knowledge Perceptive Faculties Original Thought Memory
Reason Receptivity in Training Efficiency in Execution Nervous
Energy Keenness of the Senses Use of the Voice
Primates
Chimpanzee . . . . . . . . .100 100 100 100 75 100 100 100 100 50 925
Orang-Utan . . . . . . . . .100 100 100 75 100 75 100 75 100 25 850
Gorilla. . . . . . . . . . . . .50 50 50 50 75 25 25 50 100 25 500
Ungulates
Indian Elephant . . . . . .100 100 100 100 100 100 100 75 50 25 850
Rhinoceros. . . . . . . . .25 25 25 25 25 0 0 25 25 0 175
Giraffe . . . . . . . . . . . . .50 25 25 25 25 25 0 25 100 0 300
White-Tailed Deer . . .100 100 100 25 50 0 0 100 100 0 575
Big-Horn Sheep . . . . . .100 100 50 25 50 0 0 100 100 0 525
Mountain Goat. . . . . . .100 100 100 25 100 0 0 100 100 0 625
Domestic Horse. . . . . .100 100 100 75 75 75 75 100 100 50 850
Carnivores
Lion . . . . . . . . . . . . . . . .100 100 50 75 50 75 50 100 100 25 725
Tiger . . . . . . . . . . . . . . .100 75 50 50 50 25 25 100 100 0 575
Grizzly Bear . . . . . . . . .100 100 50 25 50 75 50 75 100 25 725
Brown Bear (European)100 100 50 25 50 75 50 75 100 25 650
Gray Wolf . . . . . . . . . . . 100 100 100 25 75 00 100 100 25 625
Coyote . . . . . . . . . . . . . . 100 75 50 25 50 0 0 75 100 25 500
Red Fox . . . . . . . . . . . . . 100 100 50 75 100 0 0 100 100 25 650
Domestic Dog . . . . . . . . .50 100 75 75 75 75 100 100 100 100 850
Wolverine . . . . . . . . . . .100 100 100 25 100 0 75 100 100 0 700
Beaver . . . . . . . . . . . . . .100 100 100 25 100 0 100 100 100 0 725
According to the author's information and belief, these are "the most intelligent" animals: The Chimpanzee is the most intelligent of all animals below man. His mind approaches most closely to that of man, and it carries him farthest upward toward the human level. He can learn more by training, and learn more easily, than any other animal.
The Orang-Utan is mentally next to the chimpanzee.
The Indian Elephant in mental capacity is third from man.
The high-class domestic Horse is a very wise and capable animal; but this is chiefly due to its age-long association with man, and education by him. Mentally the wild horse is a very different animal, and in the intellectual scale it ranks with the deer and antelopes.
The Beaver manifests, in domestic economy, more intelligence, mechanical skill and reasoning power than any other wild animal.
The Lion is endowed with keen perceptive faculties, reasoning ability and judgment of a high order, and its mind is surprisingly receptive.
The Grizzly Bear is believed to be the wisest of all bears.
The Pack Rat (Neotona) is the intellectual phenomenon of the great group of gnawing animals. It is in a class by itself.
The White Mountain Goat seems to be the wisest of all the mountain summit animals whose habits are known to zoologists and sportsmen.
A high-class Dog is the animal that mentally is in closest touch with the mind, the feelings and the impulses of man; and it is the only one that can read a man's feelings from his eyes and his facial expression.
The Marvelous Beaver. Let us consider this animal as an illuminating example of high-power intelligence.
In domestic economy the beaver is the most intelligent of all living mammals. His inherited knowledge, his original thought, his reasoning power and his engineering and mechanical skill in constructive works are marvelous and beyond compare. In his manifold industrial activities, there is no other mammal that is even a good second to him. He builds dams both great and small, to provide water in which to live, to store food and to escape from his enemies. He builds air-tight houses of sticks and mud, either as islands, or on the shore. When he cannot live as a pond-beaver with a house he cheerfully becomes a river-beaver. He lives in a river-bank burrow when house-building in a pond is impossible; and he will cheerfully tunnel under a stone wall from one-pond monotony, to go exploring outside.
[Illustration: CHRISTMAS AT THE PRIMATES' HOUSE Chimpanzees (with large ears) and orang-utans (small ears). The animal on the extreme right is an orang of the common caste]
He cuts down trees, both small and large, and he makes them fall as he wishes them to fall. He trims off all branches, and leaves no "slash" to cumber the ground. He buries green branches, in great quantity, in the mud at the bottom of his pond, so that in winter he can get at them under a foot of solid ice. He digs canals, of any length he pleases, to float logs and billets of wood from hinterland to pond.
If you are locating beavers in your own zoo, and are wise, you can induce beavers to build their dam where you wish it to be. This is how we did it!
We dug out a pond of mud in order that the beavers might have a pond of water; and we wished the beavers to build a dam forty feet long, at a point about thirty feet from the iron fence where the brook ran out. On thinking it over we concluded that we could manage it by showing the animals where we wished them to go to work.
We set a l2-inch plank on its edge, all the way across the dam site, and pegged it down. Above it the water soon formed a little pool and began to flow over the top edge in a very miniature waterfall. Then we turned loose four beavers and left them.
The next morning we found a cart-load of sticks and fresh mud placed like a dam against the iron fence. In beaver language this said to us:
"We would rather build our dam here,—if you don't mind. It will be easier for us, and quicker."
We removed all their material; and in our language that action said: "No; we would rather have you build over the plank."
The next night more mud and sticks piled against the fence said to us,
"We really insist upon building it here!"
We made a second clearance of their materials, saying in effect:
"You shall not build against the fence! You must build where we tell you!"
Thereupon, the beavers began to build over the plank, saying,
"Oh, well, if you are going to make a fuss about it, we will let you have your way."
So they built a beautiful water-tight dam precisely where we suggested it to them, and after that our only trouble was to keep them from overdoing the matter, and flooding the whole valley.
I am not going to dwell upon the mind and manners of the beaver. The animal is well known. Three excellent books have been written and pictured about him, in the language that the General Reader understands. They are as follows: "The American Beaver and His Works," Lewis H. Morgan (1868); "The Romance of the Beaver," A. R. Dugmore (no date); "History and Traditions of the Canada Beaver," H. T. Martin (1892).
"Clever Hans," the "Thinking Horse." From 1906 to 1910 the world read much about a wonderful educated horse owned and educated by Herr von Osten, in Germany. The German scientists who first came in touch with "Hans" were quite bowled over by the discovery that that one horse could "think." The Review of Reviews said, in 1910:
"It may be recalled that Clever Hans knew figures and letters, colors and tones, the calendar and the dial, that he could count and read, deal with decimals and fractions, spell out answers to questions with his right hoof, and recognize people from having seen their photographs. In every case his 'replies' were given in the form of scrapings with his right forehoof.
"Whether the questioner was von Osten, who had worked with him for seven years, or a man like Schillings, who was a complete stranger, seemed immaterial; and this went farthest, perhaps, in disposing of all talk of 'collusion' between master and beast."
Now, by the bald records of the case the fact was fixed for all time that Hans was the most wonderful mental prodigy that ever bore the form of a four-footed animal. His learning and his performances were astounding, and even uncanny. I do not care how he was trained, nor by what process he received ideas and reacted to them! He was a phenomenon, and I doubt whether this world ever sees his like again. His mastery of figures alone, no matter how it was wrought, was enough to make any animal or trainer illustrious.
But eventually Clever Hans came to grief. He was ostensibly thrown off his pedestal, in Germany, by human jealousy and egotism. Several industrious German scientists deliberately set to work to discredit him, and they stuck to it until they accomplished that task. The chief instrument in this was no less a man than the director of the "Psychological Institute" of the Berlin University, Professor Otto Pfungst. He found that when Hans was put on the witness stand and subjected to rigid cross examinations by strangers, his answers were due partly to telepathy and hypnotic influence! For example, the discovery was made that Hans could not always give the correct answer to a problem in figures unless it was known to the questioner himself.
To Hans's inquisitors this discovery imparted a terrible shock. It did not look like "thinking" after all! The mental process was different from the process of the German mind! The wonderful fact that Hans could remember and recognize and reproduce the ten digits was entirely lost to view. At once a shout went up all over Germany,—in the scientific circle, that Hans was an "impostor," that he could not "think," and that his mind was nothing much after all.
Poor Hans! The glory that should have been his, and imperishable, is gone. He was the victim of scientists of one idea, who had no sense of proportion. He truly WAS a thinking horse; and we are sure that there are millions of men whose minds could not be developed to the point that the mind of that "dumb" animal attained,—no, not even with the aid of hypnotism and telepathy.
The bare fact that a horse can be influenced by occult mental powers proves the close parallelism that exists between the brains of men and beasts. The Trap-Door Spider. Let no one suppose for one moment that animal mind and intelligence is limited to the brain-bearing vertebrates. The scope and activity of the notochord in some of the invertebrates present phenomena far more wonderful per capita than many a brain produces. Interesting books have been written, and more will be written hereafter, on the minds and doings of ants, bees, wasps, spiders and other insects.
Consider the ways and means of the ant-lion of the East, and the trap-door spider of the western desert regions. As one object lesson from the insect world, I will flash upon the screen, for a moment only, the trap-door spider. This wonderful insect personage has been exhaustively studied by Mr. Raymond L. Ditmars, in the development of a series of moving pictures, and at my request he has contributed the following graphic description of this spider's wonderful work.
"The trap-door spiders, inhabiting the warmer portions of both the Old and New Worlds, dig a deep tunnel in the soil, line this with a silken wallpaper, then construct a hinged door at the top so perfectly fitted and camouflaged with soil, that when it is closed there is no indication of the burrow. Moreover, the inside portion of the door of some species is so constructed that it may be "latched," there being two holes near the edge, precisely placed where the curved fangs may be inserted and the door held firmly closed. Also, the trap-door of a number of species is so designed as to be absolutely rain-proof, being bevelled and as accurately fitting a corresponding bevel of the tube as the setting of a compression valve of a gasolene engine.
[Illustration: THE TRAP-DOOR SPIDER'S DOOR AND BURROW By R. L. Ditmars 1. The door closed. Its top carefully counterfeits the surrounding ground. 2. The door with silken hinge, held open by a needle. 3. The spider in its doorway, looking for prey. 4. Section of the burrow and trap- door.]
"The study of a number of specimens of our southern California species, which builds the cork-type door, including observations of them at night, when they are particularly active, indicates that the construction of the tube involves other material than the silken lining employed by many burrowing spiders. In the excavation of the tube and retention of the walls, the spider appears to employ a glairy substance, which thoroughly saturates the soil and renders the interior of the tube of almost cement- like hardness. It is then plastered with a thick jet of silk from the spinning glands. This interior finishing process appears to be quite rapid, a burrow being readily lined within a couple of hours.
"The construction of the trap-door is a far more complicated process, this convex, beautifully bevelled entrance with its hinge requiring real scientific skill. Judging from observations on a number of specimens, the work is done from the outside, the spider first spinning a net-like covering over the mouth of the tube. This is thickened by weaving the body over the net, each motion leaving a smoky trail of silk. Earth is then shoveled into the covering, the spider carefully pushing the particles toward the centre, which soon sags, and assumes the proper curvature, and automatically moulds against the bevelled walls of the tube.
"The shoveling process must be nicely regulated to produce the proper bevel and thickness of the door. Then the cementing process is applied to the top, rendering the door a solid unit. From the actions of these spiders,—which often calmly rest an hour without a move,—it appears that the edges of the door are now subjected, by the stout and sharp fangs, to a cutting process like that of a can opener, leaving a portion of the marginal silk to act as a hinge. This hinge afterward receives some finishing touches, and the top of the door is either pebbled or finished with a few fragments of dead vegetation, cemented on, in order to exactly match the surrounding soil."