The point-frame method is commonly employed to assess the dietary composition of carnivorous mammals in Japan. However, due to its time-consuming nature and dependence on microscopy for specific animal targets, there is a need for improvement. In this study, we introduce a novel technique, the ‘Simplified Area (SA) Method,’ and compare its efficacy with the point-frame method in analyzing fecal samples from the Japanese marten (Martes melampus). Fecal samples were preserved at –20°C in a freezer. Subsequently, extracted food items were dispersed onto a Petri dish, and the coverage of each food category was visually estimated and assigned scores as follows: 5 = over 50%, 2 = 10–50%, 1 = 1–10%, 0.1 < 1%. These SA scores exhibited a high degree of similarity (Whittaker’s percentage similarity (PS) > 75%) to the results obtained via the point-frame method. The key advantage of the SA method lies in its expedited processing time, requiring only approximately 5 minutes per sample, compared to the 20–30 minutes demanded by the point-frame method. Consequently, we advocate for the adoption of the SA method in carnivore fecal analysis, particularly for studies involving large sample sizes.

To effectively manage sika deer (Cervus nippon), it is crucial to monitor their establishment and population dynamics in areas where their distribution has expanded. Despite the absence of sika deer in Sayama Hills since the Meiji period, several sightings were reported in 2022. Therefore, we compiled data on sightings, photographs, and conducted interviews and camera trapping to assess the presence of sika deer in Sayama Hills post-2019. A total of 19 sightings, ten photographs, and videos were obtained, primarily between June and November 2022. Notably, sightings with individual information revealed the presence of young males with one-point antlers or velvet, suggesting temporary habitation rather than establishment. While sika deer used to constitute a component of the native mammalian fauna in Sayama Hills, their presence in an urban-surrounded area may lead to conflicts, such as encroachment into residential areas. Thus, the establishment of management guidelines and continuous monitoring are imperative for mitigating potential conflicts and ensuring the conservation of sika deer in Sayama Hills.

We conducted monitoring of a concrete crevice (approximately 25 mm wide) situated beneath a highway serving as a potential roosting site in urban and farmland areas of Kawagoe City, Saitama Prefecture, from February 10, 2021, to January 18, 2024 (a span of 277 days). During this monitoring period, on October 30, 2022, we observed the presence of Hilgendorf’s tube-nosed bat (Murina hilgendorfi) utilizing the crevice as a daytime roost. This observation is noteworthy as instances of roosts of this species occurring outside forested areas are uncommon.

Female Asian parti-colored bat (Vespertilio sinensis) are known to form nursery colonies exclusively comprised of pregnant individuals from May to August; however, there exists fragmented information regarding male roosting behavior during this period. In this study, we investigated the roosting patterns and fur color variation in adult male Asian parti-colored bats using bat boxes. Six adult males utilized bat boxes a total of 14 times during the maternity period. Male bats were observed roosting either individually or in groups of up to three individuals, and notably, never alongside females. These findings indicate sexual roost segregation and suggest the presence of a fission-fusion social system among these bats. Furthermore, the fur color of adult males remained relatively stable from April to August, contrasting with the observable light brown (reddish-brown) coloration adopted by adult females during the maternity season, accompanied by shedding of back hair. Our findings suggest the potential for distinguishing between sexes based on fur color observation during the maternity period.

Echolocation clicks emitted by narrow-ridged finless porpoises (Neophocaena asiaeorientalis sunameri) were recorded using an acoustic data logger at two stations (St.1 and St.2) in Nagoya Port from March 2017 to March 2018 and from July 2018 to July 2019, respectively. A total of 2,553 click trains were observed during the study period, with 1,079 click trains recorded at St.1 and 1,474 at St.2. Click train occurrences were more frequent in winter at St.1 and in spring at St.2. Additionally, click trains were detected more frequently at night than during the day at both stations. The mode value of the mean inter-click intervals within a click train varied between stations, with a peak of 26 ms at St.1 and a range of 12 to 32 ms at St.2. The number of clicks occurring at intervals of 10 ms or less, indicative of feeding effort, was greater at St.2 than at St.1. These differences in inter-click intervals between sites suggest variations in their specific purposes for area use within the same port.

This study aimed to elucidate the characteristics of branches and tree cavities utilized by the Ryukyu long-furred rat (Diplothrix legata). The species gathers branches and leaves, which it transports to cavities for use as resting and nesting sites. We collected branches and leaves from the cavities used by D. legata, along with data on tree species and cavity sizes in the northern part of Okinawajima Island. The branches most frequently carried by D. legata were from Castanopsis sieboldii. We observed branches with cut traces ranging in length from 50 to 544 mm. Similar branches with cut traces were also found on trees cut by black rats (Rattus rattus) on Chihijima Island and the Ogasawara Islands, but they were smaller than those carried by D. legata. Hence, the characteristics of the branches could serve as identifiers for D. legata. While D. legata predominantly occupies natural cavities, it also utilizes cavities excavated by Okinawa woodpeckers (Dendrocopos noguchii). Cavities used by D. legata are typically located in trees with a diameter-at-breast-height > 28.9 cm, indicating the necessity of mature forests for this species.

We report the first record of a road-killed Okinawa spiny rat, (Tokudaia muenninki) in the northern part of Okinawajima Island, southern Japan. The incident occurred on May 17, 2023, on a forest road traversing the southern part of Mt. Nishime-dake. Given the recent expansion of the Okinawa spiny rat’s distribution, there is growing concern about potential increases in roadkill accidents, especially if the range extends beyond Prefectural Road No. 2, a major road intersecting the World Natural Heritage area. Vigilant monitoring of the Okinawa spiny rats distribution, coupled with awareness campaigns and the implementation of preventive measures against roadkill accidents, is essential.

The habitat range of sika deer (Cervus nippon) has extended northward to the vicinity of the Shirakami Mountains, a designated World Natural Heritage Site. While food scar surveys have been utilized to monitor the presence or absence of sika deer, relying solely on food scars is inconclusive due to the cohabitation of the area by another Artiodactyl the Japanese serow (Capricornis crispus). To enhance survey effectiveness, it is crucial to identify plant species that can specifically indicate the presence of sika deer within this region. Therefore, we conducted a comparative analysis of the winter diets of these two Artiodactyla species, sika deer and Japanese serow, employing DNA metabarcoding analysis of feces. Our goal was to detect any differences in the species-specific diet between the two. The findings indicated that dwarf bamboo (Sasa kurilensis) and Pterocarya sp. were prevalent in the feces of sika deer, but absent in those of Japanese serows. Conversely, Aucuba japonica var. borealis and Japanese cedar (Cryptomeria japonica) were commonly consumed by both species. This analysis implies that basing a food scar survey on Sasa kurilensis would be the most effective indicator of the presence of sika deer in the study area during low-density periods.