This report describes the breeding of long-clawed shrews under laboratory conditions. During pairing, females waggled their waists, causing horizontal shaking of the tail, and walked around the males. Mounting was observed on the second day of pairing. In the two pairs with successful subsequent deliveries, mounting was observed 51 and 9 times with average (±SD) durations of 39 ± 59 and 56 ± 54 s, respectively. Similar multiple-mounting behavior was also observed in those pairs for which mating attempts proved unproductive. The gestational period was approximately 21–22 days. Weaning was successful in 4 of the 12 observed deliveries, and the weaning period was approximately 31–36 days. During the lactation period, the females constructed dome-like nests using straw mulch. The activity time of lactating mothers increased as the lactation period advanced. Weanlings attained almost the same body size as subadults, although their body weight did not increase until nine weeks after weaning.

Young and adult individuals of spotted seals (Phoca largha) migrate to the coast of Hokkaido, Japan. Here, their diet includes euryphagous, and they mainly feed on fish and cephalopods in shallow coastal waters. The newly weaned pups utilize small planktonic crustaceans, including krill, as prey in addition to fish prey. In this study, we aimed to analyze the dietary changes of newly weaned pups in the coastal waters of Hokkaido, Japan to understand the specific aspects and timing of these changes. Ordinal logistic regression showed that the krill-specific diet was mainly observed in March; the combined diet, which consisted mainly of krill and fish, was observed in April; and the fish-specific diet, which consisted mainly of fish, was observed in May. The newly weaned pups that lacked experience in foraging and swimming ability actively used krill as their main prey. Later, with the disappearance of sea ice, they shifted to a fish-specific diet, suggesting that the active use of bottom-layer fish is an advantageous strategy for their survival.

Pelvic bone is attached to the ischiocavernosus muscle, which is connected to the penis. The sizes of the penis and testes vary with breeding system, and they are larger in a multi-male system than in a single-male system. Harbour and Dall’s porpoises are members of Phocoenidae family. Although they have similar socialities, their breeding systems differ. Therefore, we predicted differences in the morphology of the pelvic bones in these species. Pelvic bones were collected from harbour porpoises (n = 54) and Dall’s porpoises (n = 76). The present study analyzed 29 semi-landmarks using linear regression and canonical variate analyses. Linear regression analysis showed that the length, height, and width of the pelvic bones were positively correlated with body length. There was a significant difference in the slope of the regression line between the males of both species. The shape of the pelvic bone was identified based on sex and sexual maturity; in mature males of both species, the pelvic bone at the center was wider than that in immature males and females. These differences in the size and shape of the pelvic bone are likely due to differences in the amount of the ischiocavernosus muscle attached to the pelvic bone.

The reproductive traits of the Talpidae remain unclear. Here, we applied microsatellite DNA markers (12 loci) to a female individual of the lesser Japanese mole (Mogera imaizumii) and its offspring to evaluate paternal elements and the utility of these markers for relatedness accuracy. We also evaluated the identification probability using genotype data of the wild population at three sites in Yamagata Prefecture from a previous study. As a result, of 12 loci, 10 loci were available for the identification of individuals and the detection of paternity. We concluded that the offspring were derived from single paternity. In addition, using a combination of the 10 loci, we could identify all individuals, i.e., the female and its offspring, indicating that these loci would be useful for elucidating the mating system in M. imaizumii.

In recent years, the range of Asian black bears (Ursus thibetanus) has expanded into the Abukuma Mountains. Consequently, the area has been specified as a surveillance zone by the Ministry of Environment and Fukushima Prefecture. However, its actual status is not well documented. Therefore, we set sensor camera traps for individual identification of bears and hair-snagging traps for genetic analysis in northern Abukuma Mountains (800 km²) to understand the population density and genetic characteristics of the bears and to assess the effects of the evacuation zone by the Fukushima 1^st nuclear power plant explosion. The study period was 31 months, but the bear visited the trap sites only four times. Hence, we could not determine the density and effect of the existence of the evacuation zone; however, the population density of the bears might still be low. Genetic analysis with supplemental samples that were obtained from surrounding areas suggested the presence of haplotypes that are distinctive in Ouu Mountains. This indicates that the bears found in the Abukuma Mountains came from the west. The identified individuals were all male; however, females might be already occurred. Hence, further monitoring for adequate management are essential.

Plants contain various defensive chemicals to protect themselves from consumers. Tannins are a generic term for polyphenols that bind to proteins to form insoluble complexes and are components of astringency. Tannins can harm consumers, including reduced protein digestibility and digestive tract damage. Although tannins are widely distributed in the plant kingdom, there is limited information on tannins in plants in Japan. In the present study, 349 plant species were used in the screening analysis to characterize the distribution of tannins. Tannins were detected in 174 species (49.9%), including plants with a recorded mammalian foraging. However, the selectivity and physiological responses of mammals to tannin-containing food resources remain unknown. Further physiological studies on plant-consumer interactions, as well as detailed food habit studies on mammals, are required.

On May 11, 2022, three individuals of the Sado shrew Sorex shinto sadonis were found in the stomach contents of a Japanese forest rat snake, Euprepiophis conspicillatus, on southwestern Sado Island. This critical report shows a new habitat for this subspecies, for which ecological knowledge, such as distributional information, is lacking. This is the first record of shrews found in the stomach contents of Japanese forest rat snakes. Southwestern Sado Island is at a lower elevation than the Osado Mountains (northern part of the island) and the northeastern part of the Kosado Mountains (southern part of the island), where Sado shrews have been found in previous studies. Moreover, the vegetation is a warm secondary forest dominated by Quercus serrata and Camellia japonica, unlike the cool-temperate forests of Osado and the northeastern Kosado Mountains. This finding suggests that the Sado shrew can live in secondary forests at 300 m. In addition, the fact that individuals of different ages were observed in this study provides valuable data indicating that a breeding population of this subspecies lives in the area.

The masked palm civet (Paguma larvata), distributed in Honshu and Shikoku, Japan, is considered an invasive species based on DNA analyses in previous studies; however, its invasive routes are still unclear. In this study, we analyzed the mitochondrial DNA cytochrome b gene and the control region (1,663 bp) of four animals collected in Shimane Prefecture, Japan, where they have recently invaded, and compared their invasive routes with the results of previous studies. The haplotypes identified in all four animals were identical. The haplotype was new (JA4/J4), with one nucleotide difference from haplotype JA4/J3 previously found in Shikoku, and was closely related to JA4/JT3, which is distributed widely in Chubu (Central Honshu) and Shikoku. Although this study examined only four animals, the obtained genetic data can be invaluable for further studies of the populations of western Honshu, where little information on masked palm civets is available. Future studies analyzing more animals from the Chugoku District, including Shimane, could also contribute to understanding their origin and population structures in Japan.