The Dancing Mouse: A Study in Animal Behavior. Robert Mearns Yerkes
R. Mr. Bateson's revisions of Mendel's theory of heredity. Biometrica, Vol. 2: 286–298. 1903.
31. ZOTH, O. "Ein Beitrag zu den Beobachtungen und Versuchen an japanischen Tanzmäusen." Archiv für die gesammte Physiologie, Bd. 86: 147–176. 1901.
32. ANONYMOUS. "Fancy Mice: Their Varieties, Management, and Breeding." Fourth edition. London: L. Upcott Gill. No date.
CHAPTER I
CHARACTERISTICS, ORIGIN, AND HISTORY
The variety of mouse which is known as the Japanese dancing or waltzing mouse has been of special interest to biologists and to lovers of pets because of its curious movements. Haacke in Brehm's "Life of Animals" (7 p. 337)[1] writes as follows concerning certain mice which were brought to Europe from China and Japan: "From time to time a Hamburg dealer in animals sends me two breeds of common mice, which he calls Chinese climbing mice (Chinesische Klettermäuse) and Japanese dancing mice (Japanische Tanzmäuse). It is true that the first are distinguished only by their different colors, for their climbing accomplishments are not greater than those of other mice. The color, however, is subject to many variations. Besides individuals of uniform gray, light yellow, and white color, I have had specimens mottled with gray and white, and blue and white. Tricolored mice seem to be very rare. It is a known fact that we also have white, black, and yellow mice and occasionally pied ones, and the Chinese have profited by these variations of the common mouse also, to satisfy their fancy in breeding animals. The Japanese, however, who are no less enthusiastic on this point, know how to transform the common mouse into a really admirable animal. The Japanese dancing mice, which perfectly justify their appellation, also occur in all the described colors. But what distinguishes them most is their innate habit of running around, describing greater or smaller circles or more frequently whirling around on the same spot with incredible rapidity. Sometimes two or, more rarely, three mice join in such a dance, which usually begins at dusk and is at intervals resumed during the night, but it is usually executed by a single individual."
[Footnote 1: The reference numbers, of which 7 is an example, refer to the numbers in the bibliographic list which precedes this chapter.]
As a rule the dancing mouse is considerably smaller than the common mouse, and observers agree that there are also certain characteristic peculiarities in the shape of the head. One of the earliest accounts of the animal which I have found, that of Landois (22 p. 62), states, however, that the peculiarities of external form are not remarkable. Landois further remarks, with reason, that the name dancing mouse is ill chosen, since the human dance movement is rather a rhythmic hopping motion than regular movement in a circle. As he suggests, they might more appropriately be called "circus course mice" (22 p. 63).
Since 1903 I have had under observation constantly from two to one hundred dancing mice. The original pair was presented to the Harvard Psychological Laboratory by Doctor A.G. Cleghorn of Cambridge. I have obtained specimens, all strikingly alike in markings, size, and general behavior, from animal dealers in Washington, Philadelphia, and Boston. Almost all of the dancers which I have had, and they now number about four hundred, were white with patches, streaks, or spots of black. The black markings occurred most frequently on the neck, ears, face, thighs, hind legs, about the root of the tail, and occasionally on the tail itself. In only one instance were the ears white, and that in the case of one of the offspring of a male which was distinguished from most of his fellows by the possession of one white ear. I have had a few individuals whose markings were white and gray instead of white and black.
The method by which I was able to keep an accurate record of each of my dancers for purposes of identification and reference is illustrated in Figure 1. As this method has proved very convenient and satisfactory, I may briefly describe it. With a rubber stamp[1] a rough outline of a mouse, like that of Figure 1 A, was made in my record book. On this outline I then indicated the black markings of the individual to be described. Beside this drawing of the animal I recorded its number, sex,[2] date of birth, parentage, and history. B, C, and D of Figure 1 represent typical color patterns. D indicates the markings of an individual whose ears were almost entirely white. The pattern varies so much from individual to individual that I have had no trouble whatever in identifying my mice by means of such records as these.
[Footnote 1: For the use of the plate from which this stamp was made, I am indebted to Professor W.E. Castle, who in turn makes acknowledgment to Doctor G.M. Allen for the original drawing.]
[Footnote 2: I have found it convenient to use the even numbers for the males and the odd numbers for the females. Throughout this book this usage is followed. Wherever the sex of an individual is not specially given, the reader therefore may infer that it is a male if the number is even; a female if the number is odd.]
All of my dancers had black eyes and were smaller as well as weaker than the albino mouse and the gray house mouse. The weakness indicated by their inability to hold up their own weight or to cling to an object curiously enough does not manifest itself in their dancing; in this they are indefatigable. Frequently they run in circles or whirl about with astonishing rapidity for several minutes at a time. Zoth (31 p. 173), who measured the strength of the dancer in comparison with that of the common mouse, found that it can hold up only about 2.8 times its own weight, whereas the common white mouse can hold up 4.4 times its weight. No other accurate measurements of the strength, endurance, or hardiness of the dancer are available. They are usually supposed to be weak and delicate, but my own observations cause me to regard them as exceptionally strong in certain respects and weak in others.
[Illustration: FIGURE I.—Typical markings of dancers. A, blank outline of mouse for record. B, markings of No. 2 [symbol for male], born September 7, 1905, of unknown parents, died March 30,1907. C, markings of No 43 [symbol for female], born November 10, 1906, of 212 and 211. D, markings of No. 151 [symbol for female], born February 28, 1906, of 1000 and 5, died February 26, 1907.]
What the Japanese have to say about the dancing mouse is of special importance because Japan is rather commonly supposed to be its home. For this reason, as well as because of the peculiar interest of the facts mentioned, I quote at length from Doctor Kishi (21 p. 457). "The dancing mouse has received in Europe this name which it does not bear in its own home, because of the fact that the circular movements which it makes are similar to the European (human) dance. Sometimes it is also called the Japanese or Chinese mouse; originally, however, China must have been its home, since in Japan it is mostly called 'Nankin nesumi,' the mouse from Nankin. When this animal came from China to Japan I shall inquire at a later opportunity. There were originally in Japan two different species of mouse, the gray and the white; therefore in order to distinguish our dancing mouse from these it was necessary to use the name of its native city.
"In Japan, as in Europe, the animal lives as a house animal in small cages, but the interest which is taken in it there is shown in quite another way than in Europe, where the whirling movements, to which the name dancing mouse is due, are of chief interest. For this reason in Europe it is given as much room as possible in its cage that it may dance conveniently. In Japan also the circular movements have been known for a long time, but this has had no influence upon our interest in the animal, for the human fashion of dancing with us is quite different from that in Europe. What has lent interest to the creature for us are its prettiness, its cleverness in tricks, and its activity. It is liked, therefore, as an amusement for children. For this purpose it is kept in a small cage, usually fifteen centimeters square, sometimes in a somewhat broader wooden box one of whose walls is of wire netting. In this box are built usually a tower, a tunnel, a bridge, and a wheel. The wheel is rather broad, being made in the form of a drum and pierced with holes on one side through which the animal can slip in and out. Running around on the inside, the mouse moves the wheel often for hours at a time, especially in the evening. Moreover, there are found in the box other arrangements of different kinds which may be set in motion by the turning of the wheel. No space remains in the box in which the animal may move about freely, and therefore one does not easily or often have an opportunity to observe that the animal makes circular movements,