We assessed the dietary profile of the large Japanese wood mouse (Apodemus speciosus) inhabiting the islands of the Seto Inland Sea and adjacent areas by DNA metabarcoding analyses of feces with the chloroplast trnL (UAA) P6 loop intron region and the mitochondrial cytochrome c oxidase subunit I gene as DNA-barcoding markers. The results indicated that A. speciosus consumed a variety of food items. Fagaceae (Quercus sp.) and Rosaceae were frequently utilized plant families, and the Lepidoptera (Noctuidae) was the frequently utilized animal family. The acorn-producing Quercus species was found to be a fundamental diet, while Rosaceae might be characteristic in temperate regions. The high dependence on the Noctuidae moths as an animal dietary component implies that A. speciosus may be reducing the pest abundance in orchards. Technical pitfalls surrounding the DNA metabarcoding methods for feces of the small rodent were also discussed.

Phylogenetic constraints and ecological factors have been suggested as alternative key factors in the evolution of animal sociality. The mara (Dolichotis patagonum) is a cavid rodent endemic to Argentina that has the particularity of being monogamous with a communal breeding system. Researches on reproductive behavior of mara in its natural habitat have been restricted to Peninsula de Valdés (PV). In this work, we studied the breeding behavior of the mara in Sierra de las Quijadas National Park (SQNP). A census to locate mara's dens in 230 ha, was conducted through adjacent line transects of five meters width. After locating the dens, we followed their reproductive activity using camera traps. A density of 4.34 randomly distributed dens/ha was found. No communal breeding was observed. Breeding season extended from October to June. Estimated density was from 0.16 to 0.24 reproductive adults/ha. The survival rate of juveniles was 31.3%. These observations differ from those reported for the species. Resource dispersion hypothesis could explain both reproductive strategies prevailing in the extremes of its distribution, SQNP (solitary breeding) and PV (communal breeding). The intraspecific variability registered enhances the importance of ecological factors in determining sociality traits for the mara.

We investigated the efficiency of discarded drink containers compared with other methods widely used in small mammal studies (live trapping and diet of generalist predators). We collected 225 beverage containers (bottles and cans) from 44 sampling places, and 376 small mammals of seven small mammal species were identified. Species accumulation curves emphasized significant differences between methods, with higher species density detected by genet scats, intermediate by live trapping, and lower species density by discarded drink containers. The frequency of small mammal guilds in bottles and cans was significantly biased, shrews being oversampled and rodents undersampled, with a reversed pattern in genet scats. Our results suggested that the efficiency of discarded containers was limited by several factors: spatial issues concerning small sampling area (few square meters) and aggregation, temporal issues regarding long-lasting (and undetermined) effects in the field, trapping issues related to multiple capture power (capturing one or more individuals simultaneously), container size, selectivity (shrew-biased), and low detectability of some common species.

Mating in harvest mice, Micromys minutus, was observed by introducing males to females that were in cyclic estrus (CE), that had just delivered pup (postpartum estrus, PPE), or that were not pregnant but lactating after PPE (lactational estrus after PPE: LEAP). Copulation leading to pregnancy and weaning of pups occurred at every trial for CE (n = 11) and for PPE (n = 6). In LEAP, estrus with copulation and subsequent pregnancy occurred at each of seven mating trials. At six of these trials, weaning of pups occurred as well. The mean length of gestation (± SE) was 17.55 ± 0.12 days for mating in CE, 17.56 ± 0.17 days for mating in PPE, and 17.75 ± 0.20 days for mating in LEAP. Generalized linear mixed modeling found no significant effect of the type of estrus at mating on gestation length. The number of pups conceived from mating in the three estrus types did not significantly differ. Mating and pregnancy in the lactation period (PPE and LEAP) had no significant effect on the number of pups at weaning that were suckling during mating.

Spatial separation and dietary differences may allow the coexistence of similar sized ungulate species. Over the past two decades, populations of the sika deer (Cervus nippon) have increased markedly and overlapped with the habitats of the Japanese serow (Capricornis crispus). Recently, the Japanese serow population has declined and shifted its habitat from higher to lower altitudes in Shikoku, Japan. To examine the potential for the coexistence between the Japanese serow and the sika deer, seasonal dietary and habitat overlaps were investigated in a warm temperate area in Shikoku. Although fecal analyses showed a high dietary overlap between the Japanese serow and the sika deer, the camera trap results revealed the differences in habitat uses between the two species: the Japanese serow utilized steep rocky slopes, whereas the sika deer appeared more frequently in grasslands. Artificially created grasslands on the present study area would contribute to the difference of habitat utilization between the two species.

Fences are the most effective defenses against crop damage by deer. If properly constructed and maintained, fences mitigate crop damage. However, it is difficult to enclose farmland completely when a fence crosses a river. This study evaluated the effectiveness of olfactory (wolf urine), visual (flashlight), and sound deterrents against deer at the intersection of river and fence. These deterrents were used for four weeks; the no-treatment control period was also four weeks. The treatments were tested six times. Sensor cameras detected deer intrusions into the fenced area. The sound, flashlight, and wolf urine treatments were 80%, 54%, and 57% more effective in preventing deer intrusions than the control, respectively. Statistically significant efficacy was detected only for the sound treatment. Previous studies reported that sound deterrents were ineffective, but this study revealed efficacy of the sound deterrent; this disparity could be due to the use of an attractant, since most studies employed food to test deterrent effectiveness. The short-term (four-week) tests demonstrated the effectiveness of the sonic device; however, long-term tests revealed that the efficacy declined with long-term usage (habituation effect). Use of the device should be limited, i.e., for no longer than one month.

Food habits and dietary overlaps of the three sympatric mesocarnivores (golden jackal Canis aureus, red fox Vulpes vulpes, and stone marten Martes foina) in a mountain-forest region in central Bulgaria were investigated. These species showed high dietary overlaps, commonly consuming rodents and fruits through studied period. Moreover, their dietary overlaps were higher in November that in the earlier months, because rodents were a predominant prey for all carnivore species in this season. Spatiotemporal separations of smaller carnivores from larger competitor may enable their sympatry, when their food habits were similar.

We studied an occurrence of chromosomal aneuploidy for ten individuals in the small Japanese field mouse, Apodemus argenteus, from the western mountainous area of Kanagawa Prefecture, Honshu, Japan. Eight of the individuals examined showed the standard 2n = 46 and FNa = 48 constitutions as the most frequent karyotype. However, of those eight individuals, seven carried an inter-cellular mosaicism with a few metaphases carrying a small-sized supernumerary element. In addition, one individual showed an aneuploid complement that included a small-sized bi-armed B chromosome (2n = 47). The B chromosome consisted of the C-heterochromatin and was characterized by delayed fluorescence by the quinacrine mustard staining, suggesting that its feature is identical to the B chromosomes previously confirmed in other localities. Moreover, an XO female showing a standard autosomal complement with only one X chromosome (2n = 45, XO) was also recognized. According to the present observations, these chromosomal aneuploidies are retained in wild populations of A. argenteus as constantly occurring phenomena.