I performed a phenological survey on the plant diets of wild Japanese macaques (Macaca fuscata) on Kinkazan Island, northern Japan. I conducted a monthly survey between April 2021 and March 2023, during which I checked leafing, flowering, and fruiting of 31 plant species along pre-set routes within the home range of a target macaque troop. Subsequently, I examined the relationship between phenology and the macaques’ feeding pattern. For leaves and flowers, the feeding seasons of most plant species corresponded with the first half of the leafing and flowering seasons, respectively. For fruits, on the other hand, feeding often continued after their fruiting season, which may likely be due to macaques’ feeding on fallen fruits on the ground. Additionally, I found that several nut/achene species did not fruit during the study period, likely due to interannual variation in fruiting. To better estimate food availability, which is essential for understanding the feeding strategies of macaques, it may be necessary to perform combined phenological and vegetation surveys across multiple years for obtaining plant density.

The purpose of this survey was to further enhance the academic and social contributions that primatology in Japan has made to date by identifying the current needs of Primate Society of Japan (PSJ) members and what is needed to create an environment in which members can have open discussion.　

An online survey was conducted over a 46-day period from August 16 to September 30, 2022, targeting members of the PSJ as of August 16, 2022. The number of responses was 159, and the response rate was 35.8%, as there were 444 members at the time of the survey. Of the 159 responses, 155 were valid, of which 13 respondents were unable to make multiple selections due to incomplete answers, so we analyzed the responses of 142 respondents to Q8-2 and Q10-1, and the results of the 155 respondents to other questions are presented.

The survey was divided into two basic categories: one for analysis as the opinions of the respondents as a whole, and the other for comparison among generations to analyze and compare their different perspectives. In the case of comparison among generations, the 20s and 30s were classified as the younger generation (n=55), the 40s and 50s as the middle generation (n=69), and the 60s, 70s and 80s as the veteran generation (n=31). For multiple-choice questions, the overall ratio of the number of responses for each option to the total number of respondents is described, and for each age class, the ratio of the number of responses for each option in each class to the total number of respondents in each class is described. Concerning free descriptions, categories were extracted by coding the entire descriptions, referring to Sakai's (2001) method, and the text showed the resulting category-descriptions in < >.

Through this questionnaire, we have identified some possible ways to enhance the academic and social contribution of the PSJ by making a forum for open discussion among members of the society with diverse backgrounds, including younger generations. The future of PSJ should continue to be discussed among the members of the new forum. The English results are shown in the supplementary document.

The stump-tailed macaque, Macaca arctoides, is the most distinctive of its genus in terms of reproductive anatomy and behavior. The ultimate challenge is to clarify why unique reproductive traits have evolved in this species. Although there have been some previous studies of sexual behavior in this species, the animals studied were born in captivity or reared in laboratory conditions that do not reflect their natural environment. Because very few ecological and ethological studies have been conducted under natural conditions, there is still a lack of knowledge about this species. This was the starting point for this study. As the main outcome of this study, long-term behavioral observations were conducted with a wild population of stump-tailed macaques, and the mating strategies of the males were analyzed based on behavioral data. In parallel with this behavioral study, my colleagues and I conducted paternity tests using 10 microsatellite DNA markers on DNA samples collected using our newly developed non-invasive sampling method. The results of the paternity tests will be compared with the behavioral data to determine whether the mating strategies of the males have provided them with reproductive success. In the process of comparing mating strategies and reproductive success, a number of ancillary results were obtained, including a discussion of the unique facial expressions seen during copulating and the function of copulation calls by males. In this article, I describe and organize the background of each of these results and provide future perspectives.