Gombe Stream Research Articles

On Williams's Review of Evolutionary Biology and Human Social Behavior

American AnthropologistVolume 84, Issue 4 p. 896-897 Free Access On Williams's Review of Evolutionary Biology and Human Social Behavior WILLIAM IRONS, WILLIAM IRONS Northwestern UniversitySearch for more papers by this authorNAPOLEON A. CHAGNON, NAPOLEON A. CHAGNON Northwestern UniversitySearch for more papers by this author WILLIAM IRONS, WILLIAM IRONS Northwestern UniversitySearch for more papers by this authorNAPOLEON A. CHAGNON, NAPOLEON A. CHAGNON Northwestern UniversitySearch for more papers by this author First published: December 1982 https://doi.org/10.1525/aa.1982.84.4.02a00150AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References Cited Journal of Reproductive Fertility, Supplement 28: 43– 57. Tutin, C. E. G., and P. R. McGinnis 1981 Sexuality of the Chimpanzee in the Wild. In Reproductive Biology of the Great Apes. C. E. Graham, ed. pp. 239– 269. New York: Academic Press. van Lawick-Goodall, J. 1968 The Behaviour of Free-Living Chimpanzees in the Gombe Stream Reserve. Animal Behaviour Monograph 1: 161– 311. van Lawick-Goodall, J. 1970 Tool-using in Primates and other Vertebrates. In Advances in the Study of Behavior, Volume 3. D. S. Lehrman, R. A. Hinde, and E. Shaw, eds. pp. 195– 249. London: Academic Press. van Lawick-Goodall, J. 1973 Cultural Elements in a Chimpanzee Community. In Precultural Primate Behavior. E. W. Menzel, ed. pp. 144– 184. Basel, Switzerland: Karger. Washburn, S. L. 1960 Tools and Human Evolution. Scientific American 203(9): 63– 75. Waterfall, W. 1979 Form and Function: The Anatomists' View. Mosaic 10: 23– 29. Weiss, K. 1973 Demographic Models for Anthropology. Society for American Archaeology, Memoir 27. Wolpoff, M. H. 1973 Posterior Tooth Size, Body Size, and Diet in the South African Gracile Austral-opithecines. American Journal of Physical Anthropology 39: 375– 394. Wolpoff, M. H. 1976 Some Aspects of the Evolution of Early Hominid Sexual Dimorphism. Current Anthropology 17: 579– 606. Wolpoff, M. H. 1980 Paleoanthropology. New York: Knopf. Wolpoff, M. H. 1982 Ramapithecus and Human Origins: An Anthropologist's Perspective of Changing Interpretations. In New Interpretations of Ape and Human Ancestry. R. L. Ciochon and R. S. Corruccini, eds. New York: Plenum. Wrangham, R. W. 1979a On the Evolution of Ape Social Systems. Social Science Information 18: 335– 368. Wrangham, R. W. 1979b Sex Differences in Chimpanzee Dispersion. In The Great Apes. D. A. Hamburg and E. R. McCown, eds. pp. 481– 489. Menlo Park, Calif.: Benjamin/ Cummings. Volume84, Issue4December 1982Pages 896-897 ReferencesRelatedInformation

Spontaneous sponge-making in captive chimpanzees

An attempt was made at reduplicating in captivity the conditions under which sponge-making behavior is known to occur among chimpanzees in the wild. A bottle filled with fruit juice to a depth of 3 cm was fastened outside the cage of two young female chimpanzees and leafy branches were provided in the cage. Over 21 experimental sessions of one hour each, the most proficient animal was observed to use the branches in a number of ways for absorbing and drinking the juice. Most commonly, a branch was broken, its leaves removed, the extremity inserted repeatedly into a bottle and withdrawn to lick the adhering juice. At the moset developed stage, the extremity of the branch was chewed over a length of 2 cm and reduced to a frayed condition that was found to increase four times its absorbing capacity. Similarities and differences in Gombe Stream and in this experimental situation are indicated. The sponging behavior as practised by zoo chimpanzees indicates that the example of the mother is by no means necessary for the habit to appear inyoung animals. This observation raises the question wheather the acquisition of so-called protocultural habits does not rely as much, at least, on independent reinvention as on transmission through imitation learning. It is concluded that the sponge-making behavior observed in Gomobe can most parisimioniously be interpreted as an incidental corollary of a highly variable and potentially meaningul expression of the chimpanzee's behavioral resourcefullness.

Mating patterns and reproductive strategies in a community of wild chimpanzees (Pan troglodytes schweinfurthii)

1. The sexual behaviour of a chimpanzee community in the Gombe National Park, Tanzania, was studied intensively for 16 months. Additional information came from 15 years of demographic and behavioural data accumulated by Jane Goodall and members of the Gombe Stream Research Centre. 2. The mating system of the Gombe chimpanzees is flexible and comprises three distinct mating patterns: (a) opportunistic, non-competitive mating, when an oestrous female may be mated by all the community males; (b) possessiveness, when a male forms a special short-term relationship with an oestrous female and may prevent lower-ranking males from copulating with her; and (c) consortships, when a male and a female leave the group and remain alone, actively avoiding other chimpanzees. While males took the initiative in possessive behaviour and consortships, females had to cooperate for a successful relationship to develop. 3. Data from 14 conceptions indicated that the majority of females (9) became pregnant while participating in the restrictive mating patterns, possessiveness and consorting. It could be established definitely that seven of these females were consorting during the cycle in which they conceived. As 73% of the 1137 observed copulations occurred during opportunistic mating, 25% during possessiveness, and only 2% during consortships, there was no correlation between copulation frequency and reproductive success. 4. Adult males showed differential frequencies of participation in the restrictive mating patterns. Male age, dominance rank, and the amount of agonistic behaviour directed to females showed no correlation with participation in the restrictive mating patterns. The following male characteristics did show significant, positive correlations with involvement in the restrictive mating patterns: (a) the amount of time spent in the same group as oestrous females, (b) the proportion of that time spent grooming oestrous females in groups, and (c) the frequency with which males shared food with females. While dominance ranks of the adult males showed no consistent correlation with involvement in the restrictive mating patterns, it was clear that the most dominant male did gain an advantage. He was the only male able to monopolise oestrous females by showing possessive behaviour. 5. Consortships appeared to be the optimal reproductive strategy for males (with the exception of the most dominant) and females, as they gave males the highest probability of reproductive success, and allowed females to exercise choice. However, there appeared to be disadvantages associated with consort formation; the greatest of these was the increased risk of intercommunity encounters. While all individuals have the potential to practice each mating pattern, the strategy actually used at any moment will be determined by variables both within the individual, e.g. age, physical condition, dominance position; and by social factors in the group, e.g. general stability of male dominance relationships, presence of a strong alpha male, existence of special male-female relationships.

The Development of Sociosexual Behaviour in Free-Living Baboons, Papio Anubis

The development of mounting behaviour and the communicatory functions of mounting were studied in a free-living troop of olive baboons in the Gombe Stream National Park, Tanzania, over a period of 16 months. 1. Early mounting attempts by baboon males were disoriented and incomplete. Components of mounting such as penile erection and pelvic thrusting at first occurred in isolation and in inappropriate contexts, but at 10-15 months of age, males became able, rather suddenly, regularly to orient themselves correctly to the female when mounting. 2. From about 10 months of age, thrusts became more rhythmical and increased in number per mount, and at about 12 months, intromission and the ejaculatory pause first occurred. At this age also, the frequency of male mounting reached a peak. Between 20 and 50 months of age, the characteristics of male-female mounting changed rather little, but after puberty, the proportion of mounts in which an ejaculatory pause occurred was twice as great as in younger age groups, and the number of thrusts required to reach ejaculation decreased. 3. Tumescent adult females were available for mounting by young males throughout the year, though young males could not gain access to females whilst they were maximally swollen and in consort with adult males. From about one year of age, males increasingly selected adult females as mounting partners. Male-male mounts, however, continued into adulthood. 4. The presence of cycling females in the troop with which young males could achieve intromission was thought to be particularly important for the development of the orientation and integration of male mounting patterns in baboons. This is supported by studies of captive peer-raised macaques, in which the course of development of male mounting behaviour tends to be delayed compared with that in naturalistic or wild groups of primates. 5. The nature and time scales of development of male mounting patterns in the genera Papio and Macaca appear to be very similar, though in olive baboons, unlike macaques, the ejaculatory pause occurred before puberty. In primates and in other mammals, important changes in mounting development seem to occur both during the early months of life and around puberty. 6. Mounts were observed in the contexts of 'dominance', play, appeasement/greeting, and enlisting as well as in a 'sexual context. Mounts between males were not always in the direction that agonistic status or play relationships would predict, and for any male-male pair, mounts could occur in either direction. The direction of mounting was dependent on the nature of the communication involved, and in one type of mounting (appeasement/greeting), it was generally the subordinate male that mounted. The general function of non-sexual mounting seemed to be to reduce the likelihood of aggression.

Troop fission in free-ranging baboons in the Gombe Stream National Park, Tanzania.

During a 13 month field study of baboons in the Gombe Stream National Park, Tanzania, the troop under observation divided into two groups. One group left the main troop to become ultimately an independent troop with a separate range. The troop fission followed a period of instability in the male status hierarchy. The events prior to and during the troop fission are described in detail and the membership of the group which left is analyzed. Social bonds prior to the fission, including kinship, determined membership in the group which left. Aggression from members of the main troop played a major role in causing the group which left to establish a new range. This fission is compared with troop fissions observed in rhesus and Japances macaques.

Individuality in a Long‐Range Vocalization of Wild Chimpanzees

Analysed sound-spectrographically 129 field tape-recordings of the pant-hooting vocalization of seven chimpanzees at the Gombe Stream National Park, Tanzania. Quantitative statistical comparisons revealed that each animal had distinctive differences, sufficient to permit observers and probably chimpanzees to identify individuals. A consistent sexual difference was found, as well as a possible ageclass difference.

Parturition in a feral baboon (Papio anubis)

During a study of feral baboons at the Gombe Stream National Park, Tanzania, the premature birth of a dead, breechborn infant was observed and photographed. The placenta was immediately eaten and the dead infant carried by the mother for two days. The birth itself attracted little attention from other troop members, but the dead infant was investigated by several baboons, especially three females who had recently become dominant to the mother in a fight.

Rhinophycomycosis entomophthorae occurring in a chimpanzee in the wild in East Africa.

A case of rhinophycomycosis entomophthorae occurring in an immature chimpanzee living in the wild in the Gombe Stream Reserve of Western Tanzania is described. The fungus Entomophthora coronata was cultured from the lesion. Treatment with small doses of iodide, sulphadoxine (Fanasil, Roche), and sulphamethoxazole/trimethoprin (Bactrim, Roche) failed to affect the lesion. With the onset of sexual maturity the lesion appeared to undergo an exacerbation. This case is discussed in relation to the disease occurring in humans and it is suggested that if infection can be induced in chimpanzees this might prove to be a model for the further study of the disease.

Aggressive behavior of chimpanzees and baboons in natural habitats

Publisher Summary This chapter discusses the aggressive behavior of chimpanzees and baboons in natural habitats. The predator–prey relation is only one aspect of the complex interactions between chimpanzees and baboons at the Gombe Stream Reserve and certainly not the most prominent aspect on a day-to-day basis. The two species clearly know each other well and they respond to each other differentially in a way that suggests the recognition of individual animals, the recognition of signals, and mutual accommodation. Overt competition sometimes occurs, especially in relation to premium foods. It is found that while the chimpanzees are generally dominant over the baboons in these encounters, the interactions are complex. Several adult male baboons may persist for several hours in harassing adult male chimpanzees who are controlling a supply of bananas. This harassment involves repeated, close-range threats, including the display of the massive canine teeth. Occasional short runs to grab for a banana also occur. However, the baboons rarely get more than a banana peel, at least until the chimpanzees have had an abundant intake. In these persistent agonistic encounters over a premium food, baboons frequently break off contact with the adult male chimpanzees and attack a female or juvenile chimpanzee.

Social behavior and relationship among wild chimpanzees of the Mahali mountains

Patterns of social behavior of the chimpanzees of the Mahali Mts. are listed briefly in this paper, where behavior absent in the other subhuman primates is especially focussed upon. Some are more analogous to those of mankind than to those of the other subhuman primates. This characteristic social behavior is more or less related to the peculiar social organization of wild chimpanzees. Differences of social behavior between two local populations (i.e., of the Mahali Mts. and the Gombe Stream Reserve) have not been recognized; namely, “dialect” differentiation does not seem to exist.

The Behaviour of Free-living Chimpanzees in the Gombe Stream Reserve

The Behaviour of Free-living Chimpanzees in the Gombe Stream Reserve