We assessed the temporal changes in the parasite fauna of the large Japanese field mouse Apodemus speciosus, which served as a model to evaluate the biological effects of radioactive materials released upon the Fukushima Daiichi Nuclear Power Plant accident. Parasites were collected from 30 mice trapped before (1992) and after (2012 and 2014) the accident. Five species of parasites were identified; among these, Heterakis spumosa (Nematoda) was detected only before the accident and Raillietina coreensis (Cestoda) was detected only after the accident. This phenomenon may reflect accident-induced environmental changes affecting the abundance of paratenic and intermediate parasitic hosts. Regarding morphology, no malformations were observed in any of the isolated parasites.

　 To determine which teeth should be selected for black bear age determination, we observed the eruption time of permanent teeth in nine captive black bears (Ursus thibetanus japonicus) aged 4–12 months. In all observed bears, the lower first premolar erupted first, and all permanent teeth erupted within about 1 year of age. The last canine tooth to erupt did so in February. These results suggest that the mandibular first anterior molars are optimal for black bear age determination at the time of live capture.

　 A 24-year old female spotted seal (Phoca largha) displayed symptoms such as chronic regurgitation, vomiting, and anorexia. A contrast-enhanced computed tomography (CT) examination under sedation with midazolam and butorphanol revealed esophageal mass and multiple masses in and around the liver region of the animal. These masses were confirmed as esophageal squamous cell carcinoma (SCC) with metastasis to the pancreas and the liver upon post-mortem examination and histopathological examination. As there is a dearth of information on contrast-enhanced CT in pinnipeds, this case would be valuable in the pre-mortem diagnosis of esophageal SCC.

　 The Eurasian otter (Lutra lutra chinensis) on Kinmen Island, Taiwan, has fortunately survived because of little human disturbance for a long period, along with a highly productive artificial aquatic environment. According to surveys based on droppings and infrared camera footage in 2018, otter activity in the southwest area of Kinmen Island was significantly low, as was reported previously. However, there is a need for longer-term data in order to further discuss otter activity in each area. Furthermore, in behavior monitoring based on camera footage over a two-year period from 2017, not only were reproduction and foraging activities observed but also the utilization of artifacts by Eurasian otters. However, these also showed that many stray cats and dogs are still roaming the otter habitat. Currently, the Eurasian otter is strongly protected under the domestic laws in Taiwan and has little human disturbance. Although other conservative efforts have been conducting in addition to surveys, these are mainly being conducted only by local government, so the situation is far from reassuring. Also, it seems that many local people want further economic development, hence, a long term local conservation plan for otters on Kinmen Island should be established for the sustainability. Therefore, it is essential to conduct more effective conservative efforts in Tsushima in the future with referencing other conservation activities and problems done in other countries.