An ethogram for rhesus monkeys I. Antithetical contrasts in posture and movementкод для вставкиСкачать
An Ethogram for Rhesus Monkeys I. ANTITHETICAL CONTRASTS IN POSTURE AND MOVEMENT DONALD STONE SADE Caribbean Primate Research Center, University of Puerto Rico, P u n t a Santiago, Puerto Rico 00742 a n d Department of Anthropology, Northwestern University, Evanston, Illinois 60201 ABSTRACT Antithetical postures and movements in social displays of rhesus monkeys distinguish five moods. Movement from a high to a low position in the mid-sagittal plane indicates threat. Emphasis on movement in the frontal plane indicates subordinance. Movement from a low to a high position in the midsagittal plane indicates non-hostile, non-fearful approach. Oblique movements indicate a querying mood. Playfulness is indicated by emphasis on rotatory movements in the transverse plane. Several investigators have produced ex- tration of the posture of a hostile dog prehaustive or partial catalogues of the com- paring to attack contrasted with that of municative or expressive behavior of a fawning friendly dog exhibiting what Mucaca mulatta (Hinde and Rowell, '62; we now would call submissive or subordiAltmann, '62a; Reynolds, n.d., cited in Alt- nate behavior. A second set of illustrations mann, '68; Sade, '67, '71). These show portrayed a cat preparing to fight conconsiderable consistency and agreement trasted with the attitude of the same aniamong themselves and also with the rele- mal rubbing affectionately against the leg vant portion of Van Hooffs ('67) study of of a human. Behaviorists have since found facial expressions among the Cercopithe- that the principle of antithesis applies to cidae. Altmann's ('68) comparison of sev- a wide variety of animal taxa. Antithesis eral of these catalogues indicates that i n of displays reduces confusion between spite of good general agreement there is communicative signals, particularly bestill considerable further analysis to be tween signals implying threat on the one done before the relations between the vari- hand, and subordinance or appeasement ous behavioral elements become clear. on the other. Most users of the principle This report does not attempt to list be- of antithesis have contrasted pairs of havioral elements but rather describes communicative acts. some contrasts between postures and A consideration of the expressive posmovements which seem to characterize tures and movements of the rhesus monsome diverse moods of the rhesus monkey. key, insofar as they contrast in the direcThe report is based on observations of free- tion and orientation of movement within ranging rhesus monkeys on Cay0 Santiago, the anatomical planes, indicates that a t Puerto Rico, supplemented by examination least five moods may be distinguished by of 8 mm film records taken at the same the antithetical characteristics of their colony by the author and by James Loy. outward expression. THE PRINCIPLES OF DARWINIAN ANTITHESIS Darwin (1872) showed that moods which contrast markedly are accompanied by expressive behaviors which emphasize opposite or strongly contrasting characteristics. His example consisted of a n illusAM. J. PHYS.ANTHROP., 38: 537-542. T H E ANATOMICAL PLANES The mid-sagittal plane divides a monkey along its axis of bilateral symmetry. The frontal or coronal plane lies perpendicular to the mid-sagittal plane and parallel to the longitudinal axis of the body or the vertebral column. The transverse plane is 537 538 DONALD STONE SADE perpendicular to both the frontal and sagittal planes and transects the longitudinal axis of the body. The mid-sagittal plane undoubtedly represents a very real and important axis of self-reference for the animal in his orientations to his physical, biotic, and social surroundings (Von Uexkull, '21). The frontal and transverse planes are convenient, geometrically defined, reference loci for the anatomist in describing the relations of anatomical parts or positions, but they do not correspond to anatomically defined natural divisions of the body. Figure 1G shows the relations of the anatomical planes superimposed upon a rhesus monkey in a neutral attitude. the activation of a particular mood are minimal or absent, the animal's posture and movement may be considered neutral in respect to expressive behavior and the animal may be said to be in a neutral mood. The descriptions which follow apply to cases in which the masking effects of the primary locomotor requirements of balance and orientation are minimally present. The sketches do not contain information about the temporal patterning of the shifts in posture. The sketches only indicate the kinds of contrasts which are more easily observed in life or on film, where the temporal patterning of the changes in pose are also observable. CONCEPT OF THE NEUTRAL MOOD GENERAL AROUSAL The neuro-musculo-skeletal system carries out the primary functions of balance and locomotion. Evolution has made use of this primary system by superimposing upon it a repertoire of movements and poses which serve the function of indicating the mood of the animal and communicating it in the visual channel to conspecifics. Usually the functions of balance and locomotion will be manifest and take precedence over the expressive functions. The independence of the expressive functions in the organization of the animal's behavior is indicated by occasions when a highly aroused individual performs a communicative display with such intensity on an inappropriate substrate, such as a narrow tree limb, that he loses his balance and falls to the ground. The neuro-musculo-skeletal system also provides the mechanisms by which a n individual orients towards events, objects, or other individuals in the environment. Orientation may involve a modification in posture whether or not a mood which normally is accompanied by expressive behavior is also active at the moment. Expressive movements may be altered by the requirements of simultaneously activated locomotor or orienting movements. Unusual or bizarre postures may result when the display is directed toward a partially concealed individual, or toward one who is vertically removed from the displaying monkey. Conversely, if the modifications of posture and locomotion due to The transformation of a relaxed individual into a n aroused and alert one has often been observed. The alert state has correlates in facial expression which have been described by Van Hooff ('67), and in postdres which have been described by Hinde and Rowel1 ('62). General arousal or alertness can be distinguished from the activation of the particular moods to be discussed below. MOVEMENTS OF ATTACK An attack by a confident animal may begin with a bobbing of the head accompanied by a n open mouth directed towards the victim, grade into a lunging of the shoulders toward the victim, and finally become a charge ending when the dominant individual bites the victim. These are some of the best known of the expressive movements of the rhesus monkey and are recognized by all the above cited authors who have studied this species. Careful analysis of the behavior of the attacker show that movements from a high to a low position in the mid-sagittal plane are emphasized (fig. lA,B). If a mildly aroused attacker is not facing his opponent at the beginning of a fight, he may begin by merely turning and bobbing his head toward the victim. In the same episode, however, if the victim does not respond satisfactorily, the attacker will usually adjust his posture so that the longitudinal axis of his body is oriented directly towards the victim and the bobbing I E Fig. 1 Poses of rhesus monkeys. Sequence A, B shows movement from a high to a low position i n the mid-sagittal plane indicating threat. Pose C shows the lateral flexion in the frontal plane characteristic of a subordinate animal. Pose D shows another animal displaying subordinance. Sequence E, F shows an animal giving an upward jerk in the mid-sagittal plane. Pose G is a monkey in a neutral sitting posture upon whom the anatomical planes have been superimposed. Pose H shows one member of a wrestling pair rotating head and torso in the transverse plane. Sequence I, J, K, L shows the oblique bobbing movements of a querying animal. C 540 DONALD STONE SADE movements now involve head, shoulders, and thorax. The point here is that as the attacker becomes increasingly aroused the high to low movements in the mid-sagittal plane become exaggerated. MOVEMENTS OF SUBMISSION The postures and movements of the victim contrast strongly to those of the attacker in that they emphasize lateral flexion of the vertebral column and other movements within the frontal plane. As is well known, the victim may attempt to present both his hind quarters and his grimacing face towards the attacker simultaneously, so that the animal’s body is displayed laterally to the attacker. If the victim flees, the tendency for lateral flexion disappears, undoubtedly overridden by the requirements of rapid and directed locomotion. Nevertheless, a slight lateral flexion in the frontal plane is almost always given by a subordinate threatened by a dominant, if only for a fleeting second, and has given rise to such appellations as cringing or cowering (fig. lC,D). AMICABLE, NON-HOSTILE, NON-FEARFUL APPROACH BEHAVIOR Figure lE,F shows a display which contrasts strongly with both the movements of the threatening or attacking animal and also with the movements of a frightened subordinate. It consists of a monkey in a neutral pose rapidly extending (dorsiflexing) its head and sometimes torso upwards in the mid-sagittal plane. This movement may be repeated in a series of jerks in which the upward movement is strongly emphasized in contrast to the return downward movement. At the extreme high position the head cannot be further extended (or dorsiflexed). At this point, as if the mood were frustrated by the limitations of the cervical articulations, some rotatory movements (not illustrated) take place as the upward pointed chin strives to remove itself even further from its horizontally directed position in the neutral posture. This upward jerking display may frequently be accompanied by protrusion and smacking of the lips and a lateral and whipping motion of the tail (also noted by Altmann, ’62a; Sade, ’71; Lindberg, ’71). This display in its mildest form may consist merely of a slight elevating of the muzzle in the mid-sagittal plane accompanied by protrusion of the lips. It is given on occasion by adult males and females and juveniles of each sex when approaching either a subordinate or a dominant individual. It is often seen displayed by a n adult female approaching another female with a young infant. It is often directed towards a n infant, other than the female’s own, whom the female attempts to retrieve or kidnap. Since the display is so obviously antithetical to both those of a threatening and of a frightened and subordinate animal, the existence of an additional mood is suggested which has not been clearly pointed out in the primatological literature. The term “reassurance,” which I first used to characterize this display, indicated my interpretation that it conveyed a friendly and non-agonistic attitude on the part of the approaching animal. However, “reassurance” has previously been used by Ewer (’68) to designate behavior which tends to increase the self-confidence of the performer while simultaneously intimidating a stranger: therefore the circumlocution of the subheading. QUERYING MOVEMENTS Count (’69) pointed out that all communicative displays of vetrebrates are attempts to query the social environment since they function to elicit a response from a conspecific. Whereas some displays, such as threatening or submissive gestures, seem to function to elicit specific responses from another individual, other displays seem to function to test the mood of the second individual without necessarily bringing about any specific response. The sequence shown by figure II,J,K,L illustrates the bobbing movements often directed by monkeys towards other monkeys, humans, other species, or novel objects. The open mouth face of the monkey illustrated in figure 11,K indicates the presence of an aggressive component in this particular case. However, other examples would show that the aggressive component may be diminished, lacking, or replaced by some other mood. The aspect of this display which is antithetical to the previously discussed displays is the rapid alternation of downward and upward A N ETHOGRAM FOR RHESUS MONKEYS movements and especially the emphasis on oblique movements of the head, which crosses the mid-sagittal plane as it is lowered and raised. An animal who alternates rapidly between attack and flight shows movements which have little in common with the oblique bobbing display. An animal so motivated switches rapidly from the mid-sagittal attacking movements to the laterally flexed cowering movements of submission, A subordinate animal attacking a dominant likewise displays postures and facial expressions which are clearly resultants of the simultaneous activation of attack and flight tendencies (defensive threat) and which bear little similarity to the oblique movements discussed here. The antithesis of these oblique and erratic bobbing movements to the other displays discussed above suggests that a different mood is active, which I call the “querying mood.” PLAY Any normal movement may be exaggerated during episodes of play among monkeys and play behavior is often interpreted a s representing a n incomplete or distorted form of behavior characteristic of some other mood (Meyer-Holzapfel, ’56). However, observation of play episodes among rhesus monkeys indicates that a postural component is often present which seems to be unique to play behavior, namely rotation of the head or torso in the transverse plane (fig. 1H). An animal running towards a play episode or i n the chases which commonly occur between bouts of wrestling usually is recognized by its peculiarly bouncing or gamboling locomotion. Careful observation indicates that this type of locomotion differs from a neutral, aggressive, or subordinate type in part by the tendency of the playfully running animal to rotate its head and even shoulders and to abduct its limbs during the noncontact phases of the gait. This produces the impression of movement around the longitudinal axis of the body, or movement in the transverse plane. It may be that this tendency for movement in the transverse plane is the “metacommunicative” message which Altmann (’62b) postulated a s being necessary for play to be distinguished from activities with more serious 54 1 consequence. Another interpretation could be that because the movements of play are clearly antithetical to those of the other moods discussed above, play should be considered a mood in its own right and not simply derived from other aspects of behavior. COMPARATIVE Limitations of space preclude detailed comparison between this study and other reports. However, examination of photographs of Papio hamadryas (Kummer, ’68). Theropithecus gelada (Spivak, ’68). Miopithecus talapoin (Gautier-Hion, ’71 ) and unpublished personal observation on Cercopithecus aethiops indicate that these postural characteristics may be widespread in the Cercopithecidae. ACKNOWLEDGMENTS This work was supported by NSF grant GS-3114, and by Contract NIH 71-2003 from NINDS, NIH, HEW. Conversations with Glenn Hausfater in 1968 clarified some aspects of the displays described in this paper. Comments by Judith Breuggeman, Jane Buikstra, B. Diane Chepko-Sade, and Carol DeRousseau helped clarify obscurities in the manuscript. Mr. Hemlock made the sketches. Any faults or errors are the author’s. LITERATURE CITED Altmann, S. A. 1962a A field study of the sociobiology of rhesus monkeys, Mncaca muZatta. Ann. N.Y. Acad. Sci., 102: 338-435. 1962b Social behavior of anthropoid primates: Analysis of recent concepts. In: Roots of Behavior. Chap. 20. E. L. Bliss, ed. Harper, New York, New York, pp. 277-285. 1965 Sociobiology of rhesus monkeys. 11. Stochastics of social communication. J. Theoret. Biol., 8: 490-522. 1968 Primates. I n : Animal Communication. Chap. 18. T. A. Sebeok, ed. Indiana University Press, Bloomington, pp. 466-522. Count, E. W. 1969 Animal communication i n man-science: An essay i n perspective. In: Approaches to Animal Communication. Chap. 4. T. A. Sebeok and A. Ramsay, eds. Mouton & Co., The Hague, pp. 71-130. Darwin, C. 1872 The Expression of the Emotions in Man and Animals. University of Chicago Press, Chicago, pp. 1-366. Ewer, R. F. 1968 Ethology of Mammals. Logos Press Limited, Great Britain. Gautier-Hion, A. 1971 Repertoire comportemental du Talapoin (Miopithecus talapoin). Ext. Rev. Biol. Gabon., 7: 295-391. 542 DONALD STONE SADE Hinde, R. A., and T. E. Rowel1 1962 Communication by postures and facial expressions in the rhesus monkey (Macaca mulatta). Proc. Zool. SOC.Lond., 138: 1-21. Xummer, H. 1968 Social Organization of Hamadryas Baboons. A field study. University of Chicago Press, Chicago. Lindberg, D. G. 1971 The rhesus monkey in North India. An ecological and behavioral study. In: Primate Behavior. Vol. 11. L. A. Rosenblum, ed. Academic Press, New York, pp. 1-106. Meyer-Holzapfel. M. 1956 Das Spiel bei Saugetieren. Handb. d. Zool., 8: 1-36. Reynolds, V. n.d. 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