In this study, we investigated the diving behavior of sei whales relative to the vertical distribution of their potential prey in the western North Pacific during the summer of 2013. Acoustic time-depth transmitters were attached to two sei whales for 10.2 and 32.0 h, respectively. The vertical distribution and density (expressed as the volume backscattering strength, SV) of their potential prey were recorded by an echosounder. Diving behavior was classified into two shapes: U-shaped and V-shaped. For both individuals, U-shaped diving was associated with higher SV values than V-shaped diving and the frequency of U-shaped diving increased from late afternoon until sunset. During the daytime, dense scattering layers (presumably zooplankton) were distributed at approximately 40 m and they then migrated toward the surface around sunset. The diving depth of the whales followed the diel migration of the scattering layers and the diving was concentrated in these layers when the density became high. The results of this study indicate that sei whales change their diving depth and shapes in response to the diel vertical migration of their potential prey.

Wildlife biologists require demographic estimates to manage white-tailed deer (Odocoileus virginianus) populations. However, such data are sparse for deer in the northern lower peninsula of Michigan. During 2005–2008, we radiomarked 105 female white-tailed deer (62 adults and 43 fawns) in the northern lower peninsula of Michigan to quantify rates of survival and determine causes of mortality. Annual adult survival was 0.64±0.06 (mean ± SE) and similar to other northern deer studies, with most mortalities (n = 14 of 31) caused by hunting and deer-vehicle collisions (n = 5). Adult survival was the highest during winter (1.00) and lowest in fall (0.70±0.07). Survival of fawns during the winter–spring period was 0.74 ± 0.06 and within ranges of other northern deer studies, with all mortalities caused by predation (n = 4) and starvation (n = 3). These survival rates indicate the local deer population may be able to achieve higher densities and provide current information to parameterize population models and refine management objectives.

External factors that affect seasonal coat color changes in the Japanese marten (Martes melampus) were examined under experimental conditions. In martens, captured in Kagoshima Prefecture and exposed to a photoperiod of 10L: 14D with light intensity of 20–70 lux, molting rhythms did not synchronize with each other over six years, regardless of ambient temperature fluctuations. The cycle length from the start of one blackish color change to the next was approximately 14 months. This may be caused by a modifiable endogenous circannual rhythm that may be reset by external photoperiods. For the male kept at 14L: 10D with light intensity of 600 lux, duration of activity was 13 h, and his fur remained blackish without change for three years. The fur of female, kept under the same conditions, changed to yellowish when the duration of activity changed to 9 or 10 h, and subsequently remained brackish without molting when the duration changed to 13 h. These results show that length of time exposed to light per day is an important factor that affects coat color changes. The camera trapping survey revealed that martens with brackish coat color in winter may inhabit Kagoshima Prefecture without molting although they were rare.

To describe the maintenance process of matrilineal site fidelity in large, solitary mammals, we investigated both the site fidelity over time and the effect of kinship on the space use at a fine (home range) scale under different levels of food availability. We collected location data for female Asian black bears, Ursus thibetanus, using GPS collars and identified microsatellite DNA markers from bears in the Ashio-Nikko Mountains, Japan. We investigated autumn food resources by assessing hard mast productivity. We found high site fidelity over the years from the denning to summer season, and there was spatial proximity among related females (i.e., mother—daughter, grandmother—granddaughter, and sister—sister pairs) from spring to summer and through mid-autumn in moderate/good hard mast years. In autumns of poor hard mast years, although females used sites far from their primary home ranges, they returned to sites near their primary range before den entry. In habitats, where good denning habitat is spatially close to the spring and summer range, maternal communities may range throughout the area during the denning, spring, and summer seasons. When matrilineal site fidelity was suspended during poor mast years, it was reformed by the end of autumn.

Cold induces a transformation of adipocytes in white adipose tissue (WAT) into ‘beige’ adipocytes with a brown adipose-like phenotype in a process known as ‘browning’. In the present study, cold acclimation was characterized over 49 days of exposure to 5°C (with controls housed at 25°C) in Tupaia belangeri using physiological indices, positron emission tomography-computed tomography (PET/CT) scan, adipose tissue morphology study, and flow cytometry. The results showed that during cold acclimation, body mass and WAT mass and content increased significantly, and there were significant effects of cold exposure on the mean standardized uptake values (SUV) for inguinal, omental, and mesenteric WAT. Adipose tissue morphology showed that the abdominal omental WAT had taken on characteristics of beige adipocytes, including smaller lipid droplets, and expression of uncoupling protein 1 (UCP1). Flow cytometric analysis showed that a new cell population had appeared in WAT by day 49. In the R1 (original) and R2 (new) groups of cells, 69.6% and 95.3% of the cells were positive for UCP1, respectively. All of these results indicate that cold exposure induced WAT browning, which would increase thermogenic properties in T. belangeri under cold acclimation.

We aimed to validate a method to identify age class and sex of sika deer (Cervus nippon), which defecate fecal pellets. We collected 42 and 54 fecal samples in Nara and Yakushima, respectively. Both pellet width and length were significantly larger for adults than juveniles (1∼1.5 yrs). A discriminant model based on both width and length correctly assigned an age class for 92% of individuals in Nara and 98% in Yakushima. We genetically determined their sex based on the gel electrophoresis of two genes on sex chromosomes (SRY and ZFX/Y) amplified by PCR. For fresh feces, sex was not determined for 40% of the samples, but for the rest of the samples, sex was correctly assigned in almost all cases (28/29). However, sex was not determined in any of the samples that were analyzed at a half month or later after defecation. The proportion of young individuals could be estimated by the morphometry of fecal pellets, but the sex of the animals could not be confirmed.

Disturbance events can alter habitat properties, leading to species displacement, isolation, and/or local extinction. Therefore, understanding the interactions of potential ecological drivers on native and introduced wildlife species post-fire is critical to understand influences on distribution. We studied native Arizona gray squirrels (Sciurus arizonensis), which are believed to favor dense riparian habitat, and introduced Abert's squirrels (S. aberti), which prefer open ponderosa pine (Pinus ponderosa) forests. We examined how uncommon native Arizona gray squirrels and introduced Abert's squirrels used areas previously burned by widespread fires more than a decade prior to our study. To determine how past fire may affect squirrel habitat, we examined squirrel use and occupancy within fire altered habitats and used distance sampling to determine squirrel distribution, feeding, and nest use within a mosaic of burn severities. Occupancy and habitat use indicated that introduced Abert’s squirrels readily used post-fire conditions more than native Arizona gray squirrels, likely due to the opening of a dense understory. Arizona gray squirrels remained in unburned riparian areas; therefore, fire affected riparian areas can be directly targeted for management to increase abundance of the native species.

Wildfires occur almost every year at the end of the dry season in some dry dipterocarp forests (or dry deciduous forests) of northeastern Thailand. This study assessed the effects of a wildfire on the occurrence of variable squirrels (Callosciurus finlaysonii), gray-bellied squirrels (C. caniceps), and Indochinese ground squirrels (Menetes berdmorei). Route census surveys before and after the wildfire revealed that the frequency of occurrence of the two tree squirrels (Callosciurus spp.) did not change, whereas that of the Indochinese ground squirrel decreased. The wildfire burned bushes and grasses but did not destroy the trees, leaving the food and resting sites for the tree squirrel species intact. Therefore, wildfires in this area may have no clear effects on tree squirrel species, but negative ones on ground squirrels. The probable reasons for these findings may be the nature and extent of the wildfire, as well as the space utilization of the squirrel species.