Distribution of Japanese macaques (Macaca fuscata) has expanded nationwide and invasion of solitary animals into residential areas has become problematic for residents and local government. We collected cases on the invasion of solitary animals into residential areas and compared sexual difference of behavior. We assembled the information (observed behavior, sex of animal, home range size, invasion month, and invasion period). During the study period (1994-2016), we collected 18 cases (28 animals), among which 12 animals were females. Both male- and female- solitary animals performed 1) crop feeding, 2) invasion to houses, 3) injury to human, and 4) attack to other animal, while only females performed 5) affinity behavior to other species, 6) sexual behavior with other species and 7) object stealing were performed only by females, and only males performed 8) damage to property. The solitary male appeared mainly in winter and spring but appearance of solitary females had no seasonality. Home range sizes of solitary females were smaller than solitary males. There were sex difference also in the unique behavior observed in solitary animals. A likely reason of the invasion of the solitary female is disturbances of the troop structure due to previous measures taken against monkey crop damage, such as capture and guard fence-setting. Our study not only adds useful information for pure science of the solitary animals, but also is useful for solving future problems of solitary animals invasion into other residential areas.

Agricultural crop damage caused by Japanese macaques (Macaca fuscata) is a serious problem in Iga City, Mie Prefecture, central Japan. We conducted a long-term study of agricultural damage management and population management of the macaques over 10 years (2008-2018). During the study period, we decreased the number of macaque troops from 10 to 4, and the average number of individuals in each troop from as many as 171 to ca. 30 individuals. In parallel, we promoted community-based agricultural damage management over the study period. As a result, agricultural damage caused by macaques in Iga City were significantly reduced. In addition, the level of harm caused by the macaques decreased and the local community became more likely to take positive action. Our study demonstrated the possibility of a community-based management model. Considering future perspectives, our results can aid other areas in which serious agricultural damage is caused by the macaques.

Recent expansion of the distribution of wild Japanese macaques (Macaca fuscata) has caused serious human-macaque conflicts, including crop damage.

Capturing of the monkeys is a main countermeasure, but this does not always lead to the reduction of crop damage. It is important to not only reduce crop damage, but to also conserve endangered local monkey populations, The Japan Ministry of the Environment recently (2016) revised “The Guideline for Specific Wildlife Protection and Management Planning”, which was originally established in 2010. In the revised guidelines, the ministry recommend to conduct well-planned population management. In this paper, we introduce 20 case studies about population management based on the revised guidelines, in which either selective (capturing of specific individuals causing damage), partial (capture of part of target troop), or complete capture was performed, and evaluate the effects of these capturing methods on troop size and degree of crop damage reduction. The complete capture of a troop was performed through complicated procedures and considered the status of overall local population, which strongly reduced the level of harmfulness. The majority of the selective and partial capture of a troop also decreased the level of harmfulness.

Therefore, a well-planned population management can be useful. We recommend to use these three different methods in accordance with troop distribution of a given area, troop size, and the degree of harmfulness to be caused. Accumulating data on macaque population management is necessary to study the conditions for selecting the appropriate capturing method and for controlling population size. In addition, setting conservation standards of the local population is necessary.

We studied the crop species damaged by wild Japanese macaques (Macaca fuscata), including those found in orchards and forests, as well as garden plants, grain crops, and vegetables, to estimate the number of crop species damaged by this species across Japan. This information is useful for fundamental and applied studies of this species. Through a web and library search, we collected 488 datasets from 461 articles from 43 (out of 47) Japanese prefectures wherein macaques inhabit. The number of articles in eastern Japan, where crop raiding by macaques has become severe since the 1980s, was significantly greater than that of articles in western Japan. Macaques fed on 179 crop items, including garden plants (29 items), orchard crops (38 items), grain crops (8 items), pasture (5 items), beans (8 items), vegetables (62 items), forestry crops (7 items), and other crops (22 items). Notably, the number of damaged crop species substantially varied among the prefectures, possibly due to differences in terms of the extent of countermeasures against crop raiding by macaques. To discuss the regional variation in the preference for specific crop species, quantitative and qualitative data should be standardized among the prefectures. The information on the crops damaged by macaques is generally retrieved from government reports, which are only retained for a short period; therefore, digital archiving is necessary for their future use. In addition, we discuss future challenges about the use of information on the diet of crop-raiding macaques. Moreover, we emphasize the importance of collaboration between researchers of fundamental and applied research.