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Nicola F. Koyama - One of the best experts on this subject based on the ideXlab platform.
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Seasonal effects on reconciliation in Macaca fuscata yakui
International Journal of Primatology, 2006Co-Authors: Bonaventura Majolo, Nicola F. KoyamaAbstract:Dietary composition may have profound effects on the activity budgets, level of food competition, and social behavior of a species. Similarly, in seasonally breeding species, the mating season is a period in which competition for mating partners increases, affecting amicable social interactions among group members. We analyzed the importance of the mating season and of seasonal variations in dietary composition and food competition on reconciliation in wild female Japanese macaques (Macaca fuscata yakui) on Yakushima Island, Japan. Yakushima macaques are appropriate subjects because they are seasonal breeders and their dietary composition significantly changes among the seasons. Though large differences occurred between the summer months and the winter and early spring months in activity budgets and the consumption of the main food sources, i.e., fruits, seeds, and leaves, the level of food competition and conciliatory tendency remained unaffected. Conversely, conciliatory tendency is significantly lower during the mating season than in the nonmating season. Moreover, conciliatory tendency is lower when 1 or both female opponents is in estrous than when they are not. Thus the mating season has profound effects on reconciliation, whereas seasonal changes in activity budgets and dietary composition do not. The detrimental effects of the mating season on female social relationships and reconciliation may be due to the importance of female competition for access to male partners in multimale, multifemale societies.
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Matrilineal Cohesion and Social Networks in Macaca fuscata
International Journal of Primatology, 2003Co-Authors: Nicola F. KoyamaAbstract:In a provisioned troop of Japanese macaques (Macaca fuscata) in Arashiyama, Japan, greater adherence to Kawamura's rules of matrilineal rank inheritance and youngest ascendancy occurred among high-ranking females versus low-ranking females. Accordingly, high-ranking females formed more clustered hierarchies and low-ranking females had more dispersed hierarchies. A proximate explanation for this finding may be related to differences in how females maintain their social networks. To determine whether the clustering in the hierarchy was reflected in patterns of social cohesiveness, I compared network sizes of coalition and grooming partners for females in each third of the hierarchy. I calculated the proportion of available partners that were coalition and grooming partners within each category of relatedness (0.5 ≥ r ≤ 0.004 and r = 0). High-ranking females formed coalitions with a large proportion of their close relatives and a small proportion of their distant relatives; middle-ranking females supported an intermediate proportion of their close relatives and a small proportion of their distant relatives; and, low-ranking females formed coalitions with very few available close and distant relatives. High-ranking females groomed nearly all available close relatives and an intermediate proportion of distant relatives, whilst middle- and low-ranking females groomed a large proportion of available close relatives and a very small proportion of distant relatives. Thus, levels of clustering within the hierarchy appeared to reflect levels of social cohesion, in terms of grooming and coalition formation.
Naoki Agetsuma - One of the best experts on this subject based on the ideXlab platform.
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The Distribution of Wild Yakushima Macaque (Macaca fuscata yakui) Troops around the Coast of Yakushima Island, Japan
Primate Research, 1998Co-Authors: Shinichi Yoshihiro, Takeshi Furuichi, Masaharu Manda, Naotoshi Ohkubo, Mayumi Kinoshita, Naoki Agetsuma, Shigeru Azuma, Hajime Matsubara, Hideki Sugiura, David A. HillAbstract:A series of censuses of wild Yakushima macaques (Macaca fuscata yakui) was carried out in a 127.26km2 area around the coast of Yakushima Island, Japan. The census area was estimated to have 131 troops in total. Monkeys seem to depend on natural broad-leaf forests. Troop density was highest in the western coastal area, where the greatest population of natural vegetation remained undisturbed. In total, 1, 852 monkeys were counted, giving an estimate of 2, 000-3, 850 monkeys inhabiting the census area.
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Dietary selection by yakushima macaques (Macaca fuscata yakui): The influence of food availability and temperature
International Journal of Primatology, 1995Co-Authors: Naoki AgetsumaAbstract:I examined dietary selection by Yakushima macaques (Macaca fuscata yakui) in relation to food availability and air temperature. Multiple regression analysis indicates that both food availability and temperature influenced the selection of foods. Feeding on young leaves, seeds, and flowers was affected more by availability, while feeding on fruits, mature leaves, and fallen seeds was affected more by temperature. Feeding on insects is strongly correlated with temperature , perhaps because availability of insects increased with temperature. These results suggest that temperature influences dietary selection of Yakushima macaques by changing the energy expenditure required for thermoregulation and through its influence on the accessibility to insects, which are an important protein source for the monkeys .
Fiona A Stewart - One of the best experts on this subject based on the ideXlab platform.
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experimental primate archaeology detecting stone handling by japanese macaques Macaca fuscata
Lithic technology, 2014Co-Authors: William C Mcgrew, Takuya Matsumoto, Michio Nakamura, Caroline A Phillips, Fiona A StewartAbstract:AbstractNon-human primates using stones in nature provide a rare opportunity to compare directly the behaviour of use with the resulting lithic artifacts. Wild Japanese macaques (Macaca fuscata) customarily do “stone handling” (SH = spontaneous, solitary, non-instrumental and seemingly playful manipulation of stones). Ten populations of monkeys show at least 48 behavioral variants, 13 of which entail repeated stone-on-stone or stone-on-substrate contact that is likely to yield recognizable wear patterns. We collected 10 assemblages of stones after seeing them being used, as well as “control” stones from a nearby hillside. In the first experiment, human subjects of varying degrees of knowledge of SH were asked to separate handled versus non-handled stones. Overall they were unable to do so, but the best-informed subjects were more accurate than the totally naive ones. In the second experiment, another set of totally naive subjects was tutored on key points derived from the first experiment. They scored sig...
Keiko Shimizu - One of the best experts on this subject based on the ideXlab platform.
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Birth in Free-ranging Macaca fuscata
International Journal of Primatology, 2010Co-Authors: Sarah E. Turner, Masayuki Nakamichi, Linda M. Fedigan, H. Damon Matthews, Katie Mckenna, Hisami Nobuhara, Toshikazu Nobuhara, Keiko ShimizuAbstract:The birth process is an integral part of reproductive success in mammals, yet detailed, quantitative descriptions of parturition in nonhuman primates are still rare. Observations of free-ranging births can help to elucidate factors involved in this critical event, to contribute to our understanding of how maternal and infant behaviors during parturition affect infant survival and to explain the evolution of human birth. We provide data on the parturition behavior of 4 multiparous Japanese macaques: 2 daytime live births that we photographed and video recorded at the Awajishima Monkey Center (AMC), Awaji Island, Japan in 2006; a daytime live birth video recorded in 1993 at the AMC; and a nocturnal breech stillbirth of a captive Macaca fuscata , video recorded at the Kyoto Primate Research Institute in 2006. Certain behaviors were similar among the females, such as touching of the vulva followed by licking of fingers, squatting during contractions, and average contraction durations. Parturient females facilitated the birth manually by guiding the emerging infant. There were also dissimilarities in the duration of the labor and birth stages, condition of the infant at birth, and the mother’s behavior immediately postpartum. The mother’s postpartum behavior ranged from almost entirely infant-focused to predominantly related to the consumption of the placenta. The 3 free-ranging females all showed considerable social tolerance during labor and birth. We argue that social proximity at parturition is more common in nonhuman primates than previously emphasized, and has potential adaptive advantages.
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Cervical ripening and uterine contraction induced by prostaglandin E2-gel in pregnant Japanese monkeys (Macaca fuscata fuscata)
Journal of medical primatology, 1994Co-Authors: Keiko Shimizu, Masumi Nozaki, Kiyoshi OshimaAbstract:Effects of intracervical administration of PGE2-gel were studied in pregnant Japanese monkeys (Macaca fuscata fuscata) near term. Administration of PGE2-gel induced cervical ripening and an increase in maternal plasma PGE2 but no change in PGF2 alpha. Ultrastructural observations of the connective tissue of the cervix after PGE2-gel treatment revealed a decrease in the number of collagenous fibers. These results show that intracervical administration of PGE2-gel induces cervical ripening without induction of labor in the Japanese monkey.
Juri Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Hepatic neuroendocrine carcinoma in a Japanese macaque (Macaca fuscata).
Journal of medical primatology, 2018Co-Authors: Akihiro Hirata, Yoko Miyamoto, Akihisa Kaneko, Hiroki Sakai, Kyoko Yoshizaki, Tokuma Yanai, Takako Miyabe-nishiwaki, Juri SuzukiAbstract:Primary neuroendocrine neoplasm of the liver is extremely rare in both humans and non-human primates. The present report describes the clinical and pathological findings of an aged Japanese macaque (Macaca fuscata) with hepatic neuroendocrine carcinoma. To our knowledge, this is the first report of hepatic neuroendocrine neoplasm in macaques.
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Hepatocellular carcinoma with intracranial metastasis in a Japanese macaque (Macaca fuscata).
Journal of medical primatology, 2017Co-Authors: Takako Miyabe-nishiwaki, Akihiro Hirata, Yoko Miyamoto, Akihisa Kaneko, Hiroki Sakai, Tokuma Yanai, Akiyo Ishigami, Atsushi Yamanaka, Keishi Owaki, Juri SuzukiAbstract:Background A 23-year-old male Japanese macaque (Macaca fuscata) showed left ptosis, which progressed to exophthalmos. Methods The macaque underwent a clinical examination, CT and MRI, and was euthanized. Necropsy and histopathological examination were performed after euthanasia. Results The CT revealed and MRI confirmed an intracranial mass at the skull base with orbital extension. At necropsy, there were a large hepatic mass and an intracranial mass compressing the left temporal lobe of the brain. Histopathological and immunohistological examinations revealed that the masses were hepatocellular carcinoma (HCC) and a metastatic lesion. In both the primary and metastatic lesions, neoplastic hepatocytes were arranged mainly in a trabecular pattern. Immunohistochemically, the tumor cells were positive for cytokeratin (AE1/AE3 and CAM5.2) and hepatocyte paraffin 1 and negative for cytokeratin 7 and 20 and vimentin. Conclusion To our knowledge, this is the first case report of HCC with intracranial metastasis in a macaque.
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Characterization of Spontaneous Malignant Lymphomas in Japanese Macaques (Macaca fuscata)
Veterinary pathology, 2014Co-Authors: Akihiro Hirata, Akihisa Kaneko, Hiroki Sakai, Juri Suzuki, K. Hashimoto, Y. Katoh, A. G. Bruce, T. M. Rose, Hideki Nikami, Tokuma YanaiAbstract:Lymphomas are common spontaneous tumors in nonhuman primates but remain poorly characterized in Japanese macaques (Macaca fuscata). This study examined 5 cases of spontaneous malignant lymphoma in Japanese macaques, focusing on the immunophenotypes and presence of simian lymphocryptoviruses, which are Epstein-Barr virus-related herpesviruses in nonhuman primates. The macaques with lymphoma were 5 to 28 years old, indicating that lymphomas develop over a wide age range. The common macroscopic findings were splenomegaly and enlargement of lymph nodes. Histologic and immunohistochemical analyses revealed that all cases were non-Hodgkin type and exhibited a T-cell phenotype, positive for CD3 but negative for CD20 and CD79α. The lymphomas exhibited diverse cellular morphologies and were subdivided into 3 types according to the World Health Organization classification. These included 3 cases of peripheral T-cell lymphoma, not otherwise specified; 1 case of T-cell prolymphocytic leukemia; and 1 case of an unclas...
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Seasonal variation in the body fat of Japanese macaques Macaca fuscata
Mammal Study, 2003Co-Authors: Yuzuru Hamada, Juri Suzuki, Seiji Hayakawa, Kunio Watanabe, Satoshi OhkuraAbstract:Japanese macaques Macaca fuscata inhabit the Japanese archipelago where they experience markedly seasonal warm and cool temperate climates. Their reproduction and their nutritional status follow clearly seasonal patterns. Their status can be effectively evaluated based on their total body fat, but making such measurements has been difficult. In this study, the body fat of Japanese macaques was studied using Double Energy X-ray Absorptiometry (DXA). Adult males were found to have a median fat mass of 7% and adult females 9%. Using the 90th percentile as the criterion, we determined the levels of obesity in Japanese macaques as 17% in males and 27% in females. Fatness indicators (physique index and skinfold thickness) were found to correlate well with total body fat and fat mass percentage. Fat mass is estimated fairly well from these indicators. Fatness indicators change seasonally in artificially reared Japanese macaques.
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Baseline and stress levels of cortisol in conscious and unrestrained Japanese macaques (Macaca fuscata).
Journal of medical primatology, 2002Co-Authors: Juri Suzuki, Satoshi Ohkura, Keiji TeraoAbstract:A vest and tethering system was applied to Japanese macaques (Macaca fuscata) to collect blood samples under less stressful conditions. The level of plasma cortisol was assayed to assess the amount of stress. The pattern of plasma cortisol fluctuation during 24 hours was consistent under non-stress conditions. The plasma cortisol level was increased significantly by encounter and venipuncture. The increase was especially noteworthy when the experimental macaques encountered a large adult male, reflecting the strong stress on macaques. As venipuncture is a common medical procedure, and the encounter between macaques who have never met before occurs frequently, this vest and tethering system is useful for the assessment of the amount of stress in the daily care of macaques in a laboratory.
