Although seed traps are common for estimating seed production, it has suggested that seed traps can be wrecked by animals and it causes an obstacle to know seed production especially in habitats of large animals such as monkeys. In this study, we produced seed traps with nets and robust containers to prevent animals from destroying seed traps or snatching contents of traps, and set them in the habitat of Japanese macaques (Macaca fuscata) and wild boars (Sus scrofa), Takasakiyama, and in the habitat of Japanese macaques, Koshima. We collected seeds once every month during the fruiting season, from September to December in 2012. As a result, seed traps were neither wrecked nor knocked over, and acorns of Quercus serrata Murray, Q. glauca Thunb. and Q. salicina Blume were collected without substantial destruction of seed traps. Countermeasures for animals were suggested to be effective. The information of our seed traps can be useful for estimating seed production in habitats of large animals.

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Primatology in Japan after the World War II began in the late 1940s with the observation of shy wild Japanese macaques (Macaca fuscata) from more than 100 m. Depending on artificial feeding students succeeded to observe macaques within a short distance and identified each individual. Individual identification of calm free-ranging macaques within a short distance made it possible to record individual and social behavior of each identified individual in detail; long-lasting kin-recognition between a mother and her offspring, dominance relations among individuals and kin-groups, and then, social organization. Artificial feeding is a form of semi-experimental manipulation introduced into the wild monkey groups. This paper showed how students contributed to the primate studies under such a condition at Koshima, Takasakiyama and Katsuyama. Some behaviors, particularly cultural ones, were found only in the artificially-fed groups. Some other exceptional or uncommon phenomena or behaviors seen in non-artificially-fed groups were recorded, with many episodes sufficient for statistical analysis at artificially-fed groups. As far as we are cautious that artificial feeding is semi-experimental manipulation on the wild monkey groups, we can find out more about the important nature of human and non-human primates and evolutionary relations of them.

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The relationship between primates and lice is discussed. Lice are ectoparasites that live on the body surface of mammals and, in contrast to ticks and fleas, do not leave the host during their life cycle. Host mammals may experience adverse effects from lice, such as anemia and skin irritation. Moreover, lice are vectors of infectious diseases; for example, human lice (Pediculus humanus) transmit the epidemic typhus pathogen between humans (Homo sapiens). DDT virtually eliminated human lice in several countries after World War II. Early Japanese primatologists who began research during this period had little interest in the relationship between primates and lice. Primates groom each other to remove lice, ticks, and small objects. Prosimians use their lower incisors to groom, similar to rodents and African antelopes, whereas anthropoids, which have a retinal fovea with high visual acuity and functional fingers that allow them to find and pick small ectoparasites from the body surface, groom using their hands and mouth. Japanese monkeys (Macaca fuscata) and lice (Pedicinus obtusus, P. eurygaster) have an entwined host-parasite and predator-prey relationship. Lice lay nits on monkeys, who are hosts, in areas where hair growth is dense because the hair conceals nits from the monkeys, who are their predators. Monkeys remove and eat nits according to nit density. Given the high intrinsic rate of natural increase in lice, monkeys need to groom daily. This necessity may explain why monkeys live with grooming partners making social groups. The development of simplified techniques to estimate louse infection in primates will advance the study of socioecological models and lice infection dynamics in primate metapopulations.

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Most primates forage on insects to varying degrees. Research focusing on insect foraging behavior has been much less than that of feeding on plant foods. However, detailed studies on insect feeding behavior by primates are required to understand the effects of the relationship on the forest ecosystem. Such studies have revealed that various kinds of primates feed on insects, but the number of studies which have considered side effects of primate-insect relationships have been few. Such triadic relationships include 1) primate-insect-plant, and 2) primateinsect-parasite. Studies based on such viewpoints would lead to new perspective on the role of primate insectivory in forest ecosystems.

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Asiatic black bears and Japanese macaques are sympatric in cool temperate forests in Japan. The two species utilize similar food resources both on the ground and in trees; their major foods in spring are young leaves and shoots, and the proportion of plant fibers consumed decreases with the increase of consumption of fruits. Both species prefer fruits; however Japanese macaques adapt to consumption of fibrous foods more than Asiatic black bears, which means survivorship of Japanese macaques is secured by more fallback foods than black bears. This idea is also supported by investigation of the morphology of mastication and digestive organs, abundance of pepsinogens, and characteristics of home range utilization. The two species might compete in a scramble manner for fruits which are preferred by both species and are rare food resources. Macaques might avoid direct interference over food resources because the black bears can be a predator of macaques. The idea of preferred and fallback foods is useful to discuss phylogenetic inertia and adaptation of two species as well as conservation of them.

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