Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Amakusa-Shimoshima, approximately 200 individuals, form relatively large groups frequently exceeding 100 individuals and show high site fidelity to the area around Tsuji Island, northern coast of Amakusa-Shimoshima. This suggests that individual dolphins may have long interaction times with many other individuals. Consequently, competition between males is likely to be high and formation of alliances may be expected. However, this has not yet been confirmed. With photo-identification data collected between 2010 and 2014, we examined individual associations. Pairs of males formed significantly non-random associations for multiple years, and were seen surrounding females, many of whom were considered to be receptive at that time. Our results suggest that male Indo-Pacific bottlenose dolphins form alliances in this population, where dolphins form large groups and show high site-fidelity.

Using fecal analyses, we examined the food habits of three large herbivorous mammals, the sika deer (Cervus nippon), the Japanese serow (Capricornis crispus), and the wild boar (Sus scrofa) on Mt. Asama, central Japan. Ten fecal samples were collected in all four seasons during 2012–2013, although boar feces were not available in summer because of high-level dung beetle activity. The proportions of each food category were affected by both animal species and season. Wild boar feces had a unique composition, containing more underground plant parts and supporting organs compared with the feces of the two ruminants. Fecal samples from the sika deer were characterized by the predominance of dwarf bamboos. The fecal composition of the serow was similar to that of the deer, but contained fewer graminoids and more dicot leaves. Similarities in fecal compositions were often evident between the deer and the serow, but not between the ruminants and the boar. In the deer and the serow, the fecal particle sizes were of smaller dimensions than those of the boar, presumably reflecting morphophysiological differences. This is the first study to compare the diets of three sympatric herbivorous mammals in Japan.

On São Miguel Island, Azores (Portugal), introduced rodents may constrain conservation efforts being taken on the Macaronesian laurel forest. With the aim of assessing their foraging ecology in one of the last patches of native laurel forest, we carried out snap-trapping sessions to evaluate rodent relative abundance and diet in three habitats (exotic forest, forest plantation, and forest opening) during winter, spring, and summer. Two species (Rattus rattus and Mus musculus) were captured, and capture rates were higher in winter, particularly in native laurel forest, followed by a decrease in all habitats, with the exception of forest plantation. Stomach contents' analysis showed that invertebrates, mainly Annelida and Arthropoda, made up the greatest part of both species' diet in the four habitats, but there was an important component of plant consumption, with a large bulk corresponding to the exotics Cryptomeria japonica and Hedychium gardnerianum. Our results show that temporal variations on the relative abundance and diet of these rodents were more significant than habitat variations.

The Coiban agouti (Dasyprocta coibae) is a meso-sized rodent endemic to Coiba Island, Panama and is ostensibly classified as vulnerable to extinction. Despite this vulnerability, the ecology of the species remains unknown, and baseline estimates of population density and habitat use are needed to develop a scientifically-based conservation status and plan for the species. We recorded 2114 detections of Coiban agoutis using 30 camera traps broadly deployed across the range of habitat types on Coiba Island. We assessed 13 occupancy models using detections of unmarked agoutis, of which the best model estimated 73.3 agoutis/km², which was positively related to proportion of primary forest. Coiban agouti detection was 86% and was greater on government maintained trails than wildlife trails. Coiban agoutis were most active during daylight (06:00–19:00) hours and during late May to early June. Estimated Coiban agouti density was less than density estimates of related agouti species in tropical forests of Central America with greater predation risk, suggesting habitat may be limited for Coiban agoutis. Our results suggest that a camera trap survey would be effective for future population monitoring of Coiban agoutis, which could be designed to assess the population dynamics and guide the conservation of the species.

Body size may have a significant impact on arboreal locomotion, as small animals are more capable of navigating on smaller branches, acquire increased stability due to the lower position of the center of mass, and small substrates appear larger to them, compared to larger animals. To determine whether gaits are also affected by body size in relation to substrate size, we conducted a study on two sympatric arboreal glirid rodents of different size on simulated arboreal substrates. Our preliminary results showed that the smaller Muscardinus avellanarius used symmetrical walking gaits on the narrowest substrates (2 mm), moved significantly faster using asymmetrical bounding gaits with increased aerial phases on larger substrates, and regulated velocity via stride length. On the other hand, the larger Glis glis failed to move on 2 mm and 5 mm substrates, used asymmetrical gaits at lower velocities and decreased aerial phases on larger substrates, and regulated velocity mainly via stride frequency. We suggest that the observed differences in gait metrics may be related to body size and to the utilization of different microhabitats, reducing potential interspecific competition.

Three male anomalously white Risso's dolphins Grampus griseus were observed in the waters off Taiji, Wakayama, Japan. One (GG-1) was captured alive in 2007, and the other two (GG-2 and GG-3) were captured in 2014. The color pattern of GG-1 is approximately divided into two parts; the middle of the trunk and the lower part of the dorsal fin are white, whereas the anterior and caudal portions have dark pigmentations. GG-2 has an almost white body with some dark pigmentation in the head region, and GG-3 has a completely white body with some sparse dark flecks around the throat. All three dolphins have dark eyes similar to a normally pigmented Risso's dolphin; however, the oral mucosa of GG-2 and GG-3 and the mucosa in the blowhole of GG-3 are white to pinkish in color without any dark pigmentation. Furthermore, the mucosa in the blowhole of GG-2 is a mixture of white patches and dark pigmentation. These three dolphins are the first anomalously white Risso's dolphins to be kept in captivity; therefore they are valuable for understanding the cause of body color variations and the anomalous coloration effects in animals.

The distribution and relative frequency of gastrointestinal endocrine cells were investigated in the stomach and small intestine (duodenum and jejunum) of a lion (Panthera leo). The present study was an immunohistochemical investigation of endocrine cells showing immunoreactivity for serotonin, gastrin, or cholecystokinin (CCK). Serotonin-immunoreactive (IR) cells were detected throughout the gastrointestinal tract with the highest frequency in the duodenum. Gastrin-IR cells were numerous in the pyloric region of the stomach and moderate numbers were also seen in the duodenum and jejunum. Moderate numbers of CCK-IR cells were only detected in the duodenum and jejunum.

We studied the summer (June–August) diet of the masked palm civet (Paguma larvata) in a suburban area of Ibaraki Prefecture, using the stomach contents from road-killed carcasses. Specifically, our aim was to examine (i) monthly changes and (ii) if food habits differed between sexes, based on frequency of occurrence (FO) of the main food classes consumed. From 2009 to 2014, 61 civet carcasses were collected along the three major national highways in Ibaraki Prefecture. Civets consumed a wide range of foods such as insects, fruits, mammals, and earthworms. The FO of mammals and fruit taxa (cherries, strawberries, and persimmons) differed substantially among months, which likely reflected the peak availability of each food category/item. Females consumed amphibians, insects, and persimmons significantly more frequently than did males, likely relating to the higher food security demands of females while raising offspring. Overall, masked palm civets in Ibaraki Prefecture proved to be opportunistic and generalist feeders, eating primarily fruits and insects with a high frequency of occurrence in summer.