From The Natural History of Mammals by Francois Bourliere 1954

book design by Harry Ford.


Locomotion is in a way the fundamental activity of any animal.

In most cases these speeds have been determined by using an automobile, keeping the car abreast of the animal running on a course parallel with the road.

The hamster inflates its cheek pouches with air before taking to the water. The European mole can swin without apparent fatigue for several hundred yards, and the American star-nosed mole can do likewise. The latter has even been seen swimming beneath the ice in winter in small ponds and “sculling” with its tail

Elecrtrocardiograms of animals diving in semiliberty – in the grey seal the heartbeat falls from 100 to 10 beats per minute.

The most classic examples of gliding are to be found among the squirrels.


Mushrooms and lichens are not neglected as food by the mammals.

In the stomach of a young female of the relatively small three-toed anteater, Enders found more that a pound of ants.

It must be noted, however, that only a part of the ingested material is detected by this examination of the droppings; some foods leave no trace of their passage through the alimentary tract.

The astronomical quantities of shrimp which must be ingested daily to fill the needs to these marine monsters may well be imagined!

The Falkland sea lion also consumes cuttlefish whose “ink” colors the contents of its digestive tract a beautiful yellow.


The golden potto merely sleeps suspended by its four limbs from a horizontal branch; another species of potto (fig 8) sleeps rolled in a ball, with its head between its hind feet.

The little opposum of  Central Americam the Isthmian marmosa, bears its yound in roller-up and half-dried leaves of the banana tree.

The indo-malayan Tylonycteris pachypus, whose paws bear remarkable suckers, sleeps inside bamboo stems.

The roebuck in heat tirelessly pursues his doe by day and night, emitting a characteristic panting sound (fig 61).  This may continue for a long time, and the course followed, while often sinuous, may be circular.

The female Panama howling monkjey when in heat makes herself conspicuous by her provocative posturing and, above all, by rhythmical movements of her tongue, which is protruded and moved rapidly  in and out and up and down. The male replies with the same lingual movements.

The stag in rut gently rubs the tips of his antlers to and fro through the herbage and this stimulation promptly induced erection and ejaculation (Darling).

Such are apparently aimless running and jumping, even that odd “exercise dance” of the North American porcupine.


Young chimpanzees have a curious propensity for decorating themselves with leafy branches, flowers, and pieces of cloth or paper. Yerkes tells us also that they may smear flat surfaces with their excreta, and Kohler has seen them wet white clay with saliva and use it in the same way. Meng, the young gorilla a year and a half old observed by Julian Huxley at the London Zoo, on three occasions traced the outline of his shadow with his forefinger upon the wall of his cage.


Young otters do not enter the water of their own accord but are dragged in by their mother.

It goes without saying that such behavior should be recorded in moving pictures whenever possible, the camera lens being more impartial than the eye of the overenthusiastic observer.

So it is with the little eastern chipmunk of North America, a species in which the male and female become antagonistic no more than a few minutes after mating.


When a California ground squirrel perceives a bird of prey flying in the vicinity in utters a single short syllable of unusual loudness and carrying quality, a “cheesk” and seeks cover. If the enemy is a snake, the ground squirrel edges up to it, often coming within a foot or two, examines it, flicks its tail violently from side to side, and gives a peculiar chirp, “cheet’-ik-irr-irr-irr,” distinctive in its low, vibrating quality. If man, dog, or coyote constitutes the danger, the signal generally becomes trisyllabic, “chwee-chu-chuk.” A still different sound is produced when the danger is less immediate—a “cheesk-isk-isk-isk-isk,” with the final syllables blending in rapid succession. In the case of a mother with young, the female’s agitation in the presence of danger that is not immediately threatening is expressed by the prolonged repetition, at intervals of two or three seconds, of a low, melodious note, “chwërt,” that is more in the nature of an anxiety symptom than of a signal of alarm.  Finally, other sounds, different from the basic chirp, are produced by this species: a low growl that seems to express defiance, a sharp squeal that seems to be a cry of pain and fear, and a high-pitched squeal ending in a trill, given when one squirrel is pursued by others.


Carpenter’s researches on the behavior in nature of several species of monkeys afford other examples of auditor signals. The Panama howling monkeys have a vocabulary of at least 15 to 20 different vocalizations, all of which appear to play a very definite part in the behavior of the species. The functions of nine of them seem rather clear. The first is a voluminous barking roar, low-pitched and sonorous, uttered by the males of the clan in the presence of an enemy, of a rival clan trespassing upon the territory, or of any other disturbance. It has an inhibiting effect on all activities, such as feeding, locomotion, playing, and so on, and the members of the group prepare for attack or defense. The second signal is a deep, hoarse cluck, which may be given in series or single by the leading male before and during the troop’s movements; it initiates progressions and controls its direction. The third is a deep, gurgling sound given in a series by the adult males in the presence of some disturbing factor; it usually precedes the loud roars but seems to affect only the males and not the females or young. The fourth vocalization is a wail made on inspiration of air, followed by a groan, sounded by a female whose young one has fallen; it is repeated until the baby is recovered, and it stimulates the males to utter their loud roar. In these circumstances the fallen baby gives a series of three notes or little cries that direct the mother and the males toward it.  Another sound is a purr of several seconds’ duration, which a young individual utters in order to obtain coddling from its mother. Finally, the young at play five little chirping squeals.  The males of the clan produce two other easily recognizable sounds: a grunting sound produced when the young play at fighting and one of them utters a cry, the effect of which is to stop the fight; and a rapidly repeated grunting that is heard when the group situation involves something new and strange.


The leader of the group is not necessarily the individual highest in the social scale.

Mammals are not mere automata functioning apart from their surroundings.

The reasons for the brown rat’s success are no doubt various.

Vicunas also build up heaps of dung on their home range which may reach eight feet in diameter and a foot in thickness. Pearson often watched a herd of these animals, young and old, approach such piles of excrement and saw individuals go one by one to sniff at the material, add their contributions, and then move on.

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