著者

花村 俊吉

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.26, no.2, pp.159-176, 2010-12-20

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Chimpanzees form a multi-male/multi-female unit-group and the members of the group usually split into temporary parties. They sometimes exchange long-distance calls, pant-hoots (PH) between parties and utter PH in chorus within a party. Although most studies on PH have focused on the sociobiological functions for vocalizers or the referential functions, such studies based on individualistic or anthropocentric viewpoint do not tell us how chimpanzees interact with others by using PH. This study aims to analyze how the chimpanzees of Mahale connect their actions through PH and how they organize their social fields beyond visual contact with involvement of others in sight, by applying ethnomethodology and focusing on hearers' actions. Case analyses based on the result of their usual interval for exchanging PH (10 sec.) revealed that both vocalizers and hearers practiced the same "call-answer" form. Utilizing this form, not only vocalizers could construct an auditory social field between parties but also non-answering hearers could observe the field. Even if PH hearers headed to the place from which they heard the PH, they sometimes restrained themselves from answering to hear whether or not the answer was uttered by other parties, and anew uttered PH to elicit the voluntary answer from the party with whom they tried to interact. Meanwhile, PH hearers sometimes answered immediately regardless of the contexts in which the PH was uttered. Employing these two hands, they would organize their auditory social fields. Once two parties constructed their auditory social field by exchanging PH, one could wait for next call from another or they could get to meet visually with repeating PH exchanges. On the other hand, PH hearers sometimes terminated or deferred those interactions, which hearers' attitudes were supposed to generate the society in which the members could stay apart from each other even beyond PH distance. In conclusion, these hearers' various actions show the sociality related to their dynamic fission-fusion society and engaging in non-referential interactions. When we say that chimpanzees' society is complex, we may be often thinking of the process of interactions resulted from such their unique sociality.

著者

小川 秀司

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.26, no.2, pp.143-158, 2010-12-20

被引用文献数

1

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I studied huddling groups of Japanese macaques (<i>Macaca fuscata</i>) in the Arashiyama E troop at the "Arashiyama Monkey Park Iwatayama" in Kyoto, central Japan. Japanese macaques made physical contact with other individuals and formed huddling groups when air temperatures were low. The 99-101 adult females and 26-36 adult males in the study troop formed 345 huddling groups during 42 scan samplings in the winter of 2001, and 376 huddling groups during 52 scan samplings in the winter of 2002. The average size of huddling groups was 2.34 (range: 2-7) individuals in 2001, and 2.31 (range: 2-6) individuals in 2002. There was no huddling group of two males. Females more frequently huddled with females than with males. Two maternal kin related females huddled more frequently than unrelated females did. Mother-daughter pairs huddled most frequently. Two individuals usually huddled ventrally-ventrally, ventrally-laterally, and ventrally-dorsally. The distribution of huddling group sizes shows that the approaching individuals did not choose a particular size of huddling. However, the approaching individuals chose locations where they simultaneously contacted with two individuals 1.5 times more frequently than locations where they contacted with only one individual. This choice made the shape of huddling groups triangular and diamond-shaped more frequently than expected. By decision making of each individual, specific patterns emerged in the shape, composition, and position of each individual in huddling groups. As well as huddling behaviors, two and more primate individuals were involved in various social interactions. During the interactions, primates make their decision based on complex cognitive mechanisms and non-linear functions, compete and cooperate with the same opponents in their troop, and predict and manipulate the opponent's behavior. These traits in social interactions among primates might make their society more complex and interesting.

著者

大西 賢治 山田 一憲 中道 正之

出版者

日本霊長類学会

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.26, no.1, pp.35-49, 2010-06-20

参考文献数

31

被引用文献数

1 3

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We observed 4 cases of aggressive response of Japanese macaques (<i>Macaca fuscata</i>) toward a Japanese giant flying squirrel (<i>Petaurista leucogenys</i>) at the feeding site of the Katsuyama group.<br>When a Japanese giant flying squirrel glided over to a tree at the feeding site, almost all the adult and subadult monkeys resting around the tree mobbed the flying squirrel with threatening sounds. Immature monkeys aged &le; 2 years screamed, and the mothers retrieved their infants immediately on spotting the flying squirrel. Several peculiar high-rank adult males and females chased, threatened, and attacked the flying squirrel for 25-114 minutes, but mothers with infants seldom approached the flying squirrel. High-ranking adult males had a greater tendency to perform agonistic displays toward the flying squirrel than low-ranking adult males and females.<br>Our observation and previous reports about interspecific encounters suggest that Japanese macaques recognize the Japanese giant flying squirrel as being in the same category as raptors, which prey on Japanese macaques. This explains why the monkeys respond aggressively, which is typical of antipredator behavior, to the common behavioral features of the flying squirrel and raptor-gliding and descending nearby. However, this aggressive response does not seem to benefit monkeys in terms of avoiding predators because the flying squirrel is not actually a predator. There are 2 other possible benefits. Their sensitivity to behavioral features that resemble those of the raptors may improve their efficiency in terms of antipredator behavior towards actual predators such as raptors. In addition, adult or subadult male monkeys may display their fitness to potential mates by performing agonistic displays in response to the Japanese giant flying squirrel.<br>In order to better understand the relationship between Japanese macaques and other species, it is necessary to establish a system for collecting and sharing data on rarely observed cases.

著者

狩野 文浩

出版者

日本霊長類学会

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.28, no.2, pp.95-108, 2012-12-20

参考文献数

33

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Despite the importance of eye movement analysis in comparative and cognitive studies, the eye movements of great apes have not been examined until recently using the eye-tracking method. This is due to the lack of a non-invasive, unrestrained eye-tracking method, which is appropriate for great apes. In this review, I first show how a recent user-friendly corneal-reflection eye-tracking technique captures their eye movements accurately and stably. I then introduce several comparative studies that examined the eye movements of great apes (chimpanzees, gorillas, and orangutan) and humans when viewing still pictures of scenes and faces under similar conditions. The major conclusion of those studies is that, although the species were similar in their viewing patterns, quantitative species differences existed in those similarities. That is, great apes and humans viewed similar parts of scenes/faces for similar lengths of time. However, great apes and humans differed from each other in that (1) great apes scanned the scene more quickly and more widely than did humans in general, and (2) humans viewed the eye part of faces longer than did great apes. These species differences may reflect their cognitive differences. In future, there are at least three promising directions. (1) Movie presentations about other individuals' actions to reveal how great apes anticipate the others' action goals. (2) A wearable eye-tracker to reveal how their vision actively interacts with the environment. (3) A correlational analysis to reveal how their basic gaze patterns influence their gaze-related performances such as gaze following and observational learning.

著者

早川 祥子 Hernandez Alexander D. 鈴木 真理子 菅谷 和沙 香田 啓貴 長谷川 英男 遠藤 秀紀

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.27, no.1, pp.3-10, 2011-06-20

参考文献数

21

被引用文献数

2

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屋久島にて見つかったおよそ26歳という,非常に老齢であるニホンザル(メス)の死体の剖検結果を報告する。年齢の推定は死体の歯のエナメル質をヘマトキシリンで染色する方法によって行った。これは餌付けの経験のない野生ニホンザルとしては例外的に高齢であると考えてよい。外傷は見当たらず,病理解剖における主な病変は肺出血であり,対象個体が肺炎に罹患していたことが示唆された。さらに特筆すべきことは,このサルの体内から大量の寄生虫感染が見つかったことである。感染していたのは線虫4種,総数1524個体(<i>Streptopharagus pigmentatus</i> 1270, <i>Gongylonema pulchrum</i> 208, <i>Oesophagostomum aculeatum</i> 36, <i>Trichuris</i> sp. 10)であった。対象個体は老齢のため免疫力が低下しており,寄生虫の感染および蓄積を防ぐことができず,さらには肺炎にも感染して死を迎えたものと考えられる。

著者

北村 光二

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.24, no.2, pp.109-120, 2008-12-20

参考文献数

11

被引用文献数

1 1

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This paper aims to consider why the sphere of social phenomena is significant in the study of primates, including humans, and what aspects of the phenomena we should focus on in order to understand its significance. Although the process of making relations with others may easily become undecided, it may not be retained. We humans cope with such undecidability by paying attention to the motivation of activity easily shared by participants, or adequate readiness for regulating each other's interaction. This does not mean that the social sphere is independent of other spheres, but these characters are common to the activities of making relations with the natural environment for surviving. The social sphere should be placed in the larger range of phenomena produced by the activities of making relations with the outer world in general. An individual animal tries to decide his act of making relation with an object depending on the meaning of the object, while he tries to identify the meaning depending on his act of making relation with the object. Here, the undecidable circle is formed. The same situation is found in the case of making relations with others. That is to say, one tries to decide his act to the other depending on the other's act while the latter decides his act depending on the former's act, so that the undecidable circle is also formed here. The undecidability in the process of making relations with objects is usually perfectly hidden. However, the other's selection in the process of making relation with the object is always apparent in the social sphere. The other not only makes the undecidability apparent by making a different selection from my own, but also teaches a new way of coping with it by sharing the motivation with him or regulating the process of interaction with him.

著者

山極 寿一

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.20, no.1, pp.73-76, 2004-06-30

被引用文献数

2

著者

久世 濃子

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.20, no.1, pp.77-80, 2004-06-30

被引用文献数

3 1

著者

杉山 幸丸 岩本 俊孝 小野 勇一

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.11, no.3, pp.197-207, 1995-12-01

被引用文献数

1 7

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The number of Japanese macaques (<i>Macaca fuscata</i>) has rapidly increased under artificially provisioned conditions. At Takasakiyama it increased by 6.9 times during 22 years from 1953 to 1975 when food was given at 618kcal/day/head on average. To control the population growth, provisioning was decreased to 334kcal/day/head from 1975, after which, it increased only by 1.2 times for 19 years until 1994. Destruction of the forest from the increased number of monkeys has continued, however, through eating fruits, shoots and young leaves of the main food trees. Yearly consumption effeciency of monkeys in the forest for 1990 was calculated as 8.7%, which is near to the African elephant. As a result, the vegetation type is changing from that of natural forest. Computer simulation revealed if the population decreases to 60% of its current size and 282kcal/day/head of artificial food is given, consumption efficiency will decrease to 5.8% and the population can be kept almost stable. Further manipulation of the monkey population is necessary at present by altering mortality, natality or both. Supply of many free-ranging monkeys to biomedical experiments should not be recommended from the stance of animal welfare and the quality of experimental animals. On the other hand, temporary birth-control of each cycling female is to be considered. The principle of population control is to keep population parameters at about the level of the natural condition.

著者

半谷 吾郎

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.22, no.1, pp.43-49, 2006-06-20

被引用文献数

1

著者

加藤 英子 南部 育志 小島 康生

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.15, no.1, pp.39-52, 1999-05-01

被引用文献数

1 2

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The social relationships of 10 young adult males in a free-ranging group of Japanese macaques at Katsuyama, Okayama Prefecture, were examined pre- and post-fission. Before group fission, higher-ranking young adult males interacted less frequently with not only their mothers, but also with other matrilineally-related females than did lower-ranking males. Six-year-old males clearly formed two subgroups according to their relative rank, even though they did not form any clear subgroups at the age of two.<br>Higher-ranking males spent more time away from females of the group than did lower-ranking males. However, when it was time for artificial feeding, higher-ranking males obtained scattered food more frequently than lower-ranking males. After group fission, four of the five higher-ranking males and one of the five lower-ranking males remained in the main group, while three of the five lower-ranking males were in the fission group.<br>These differences in the social relationships of young adult males might reflect the female subgroups which appeared prior to group fission.

著者

松沢 哲郎 ハムル タチアナ クープス カテリーナ ビロ ドラ 林 美里 ソウザ クローディア 水野 友有 加藤 朗野 山越 言 大橋 岳 杉山 幸丸 クールマ マカン

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.20, no.1, pp.45-55, 2004-06-30

被引用文献数

1 15

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The present paper reports the death of wild chimpanzees through a flu-like epidemic at Bossou, Guinea, West Africa. The community at Bossou has been studied continuously since 1976. Records from the past 28 years show that the number of chimpanzees in the Bossou community has been relatively stable, at around 20 individuals. In late November 2003, chimpanzees at Bossou began to cough. Within a month, five chimpanzees died: two very old females, one adolescent male, and two infants. The mothers of the two dead infants continued to carry the corpses, which eventually mummified. One mother used a stick to chase flies away from the dead infant's body in addition to using her hands. The transportation of infants' mummified bodies may be yet another example of cultural behavior unique to this community. A 12 year-old young mother, who lost her first offspring in this epidemic, remained with the community for two months following the death of the infant, after which she disappeared, most likely immigrating to a neighboring community. We inspected the year-by-year change of age-sex composition in the Bossou community. This revealed that the proportion of old members gradually increased while many young members immigrated. Such a gradual change in the population in addition to the epidemic suggests that this community is in serious danger. The paper also introduces our conservation efforts to attempt to save this important community: the "Green corridor project" which entails the planting of trees in the surrounding savanna in order to create a passage between Bossou and the Nimba Mountains, 4 km away. This might be a model case of connecting chimpanzee habitats that have become isolated through increasing human activity, a very common problem in West Africa.

著者

中川 尚史

出版者

Primate Society of Japan

雑誌

霊長類研究 = Primate research (ISSN:09124047)

巻号頁・発行日

vol.24, no.2, pp.91-107, 2008-12-20

被引用文献数

3 3

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The male-female affinitive relationships among non-kin which persist beyond the estrus period have been known in some primates, mainly savanna baboons, Japanese macaques and rhesus macaques. I call this friendship, and review the benefits of friendships for each sex. For females, proximity and alliance of male friends disrupts antagonism by opponents, more or less, in all three species. On the other hand for the males, the effect of enhanced reproductive success seems to be negative. It is necessary to fully consider male benefits via infants in savanna baboons. Since it is highly possible that baboon males take care of a female friend's infant that he sired in the past, such friendships, especially in infanticidal baboons, would evolve through kin-selection rather than reciprocal altruism. When it comes to reciprocal exchange of benefits between a male and female, it seems that females play a positive role in the maintenance of friendships, as overall benefits seem to be female-biased. Socio-ecology can offer explanations for the ultimate cause of friendships. However, its explanatory power is not enough to explain the following observations: two non-troop males visit a group of Japanese macaques in coastal forest, Yakushima on separate days during a mating season. They received grooming one-sidedly by a female and soon left the group without copulating. These two cases seemed to be interactions between old friends, but the reciprocity cannot be formed. As the reunion with an old female friend of a male after immigration rarely occurs, mal-adaptive behavior would not be a problem. Socio-ecology does not explain such rarely occurring events. However, we can not ignore such cases just because they rarely happen. It is one aspect of the Japanese macaque society that monkeys "renews" old friendship.