Sex and age compositions of wild Japanese monkeys captured as agricultural pests in Shiga prefecture for 11 years from 1981 to 1991 were studied. The composition of sex and age of 7 wild troops on Kyoto and Hyogo prefectures was also examined for comparison. The rate of males over 4 years old were higher in captured monkeys as agricultural pests than in wild troops. Most of captures as agricultural pests were performed in restricted seasons and areas. Over harvesting will exterminate some local populations of wild Japanese monkeys. We propose a moratorium on the capture as agricultural pests until the monitoring systems on influences to wild populations by captures are established.

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Fossil specimens of two macaques are reported as Macaca cf. fuscata. 1) Specimens of ‘Fujisawa skull’ were discovered in a late Pleistocene site in Fujisawa, Kanagawa Prefecture. Its upper facial skeleton, lacking the mandible, was reconstructed based on the three discovered fragments of the cranium. It is difficult to estimate its sex. Its overall size as a whole corresponds to that of the female of the living Japanese macaque (Macaca fuscata) but its cheek tooth dimensions are relatively large, corresponding to those of male living Japanese macaques. Compared to the skulls of living Japanese macaques, the Fujisawa skull has some unique characteristics, such as a nallow nasal aperture. 2) A right humerus from a middle Pleistocene site at Yarimizu, a suburb of Kisarazu, Chiba Prefecture is perhaps the oldest specimen among the fossil macaques of known age in Japan: its age being about three hundred thousand years old. Morphologically it resembles robust humeri of males of the living Japanese macaque.

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Mechanisms controlling seasonal breeding in Japanese monkeys (Macaca fuscata fuscata) were studied. 1) Analysis of a total of 310 births recorded at our Institute over 12 years revealed that births were limited to the period from March to August with a peak in May. No difference was found in the birth season between outdoor and indoor samples, but the time of peak of births was slightly earlier in indoor than in outdoor samples. 2) In both monkeys housed indoors and outdoors, clear seasonal differences were observed in the hormonal profiles: Monkeys exhibited cyclic endocrine patterns characteristic of ovulatory cycles during the breeding season (autumn and winter), while anovulation persisted throughout the nonbreeding season (spring and summer). 3) Estradiol-treated ovariectomized monkeys exhibited marked seasonal changes in response to the negative feedback action of estradiol on LH secretion: Serum LH remained high during the breeding season, but decreased to very low levels during the nonbreeding season. There was no difference in the positive feedback action of estradiol on LH secretion between the breeding and nonbreeding seasons. 4) Artificial manipulation of photoperiod alone had no effect on the manifestations of annual reproductive cyclicity of Japanese monkeys, whereas simultaneous manipulation of photoperiod and ambient temperature was at least to some extent effective in modifying the ovarian functions. 5) Serum melatonin exhibited diurnal changes with high values in nighttime and low values in daytime both in monkeys housed indoors and outdoors. These results suggest that seasonal breeding of the Japanese monkey is governed by biannual changes in the response of the hypothalamo-hypophysial axis to the negative feedback action of estradiol, and that multiple annually cyclic environmental factors appears to influence on the seasonal breeding of this animal.

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