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In 1980 and 1981, eight and nine individual sika deer Cervus nippon were reintroduced in southern Hokkaido, Japan, respectively, to address population declines in this species during 1900s. As recent population growth has led to human-wildlife conflicts, this study investigated the responses of sika deer to resource availability and geomorphic factors during the summer and winter seasons in southern Hokkaido. Global positioning system-collared data collected from 2016 to 2018 were used to assess the home range patterns and habitat selection of 14 female sika deer located in Mount Esan and Shiriuchi. The core home range size was defined using a 50% kernel density estimation that indicated a larger home range in winter than summer for all deer. Habitat selection was assessed using generalized linear mixed models. The results showed variation in habitat selection between resident deer of Mount Esan and Shiriuchi, as well as migratory deer in Shiriuchi during summer. Resident deer in Mount Esan and Shriuchi preferred areas closer to crops during summer. Interaction effects revealed that migratory deer utilized natural grassland close to forest edge habitat in Shiriuchi. By contrast, resident deer in Shiriuchi selected forest edge habitat and natural grasslands close to crops. In winter, low elevation was the most important habitat factor for all deer across the study area. Thus, sika deer habitat selection depends on resource availability in summer and topographic factors in the winter.

The sika deer (Cervus nippon yesoensis) population in the Ramsar-listed Kushiro Wetland has increased in recent years, and the Ministry of the Environment of Japan has decided to take measures to reduce the impact these sika deer are having on the ecosystem. However, their seasonal movement patterns, i.e., when and how the deer inhabit the wetland, remain unclear. Thus, we examined seasonal movement patterns and the population structure of sika deer in the Kushiro Wetland from 2013 to 2015 by analyzing GPS location data for 28 hinds captured at three sites in the wetland. Seasonal movement patterns were quantitatively classified as seasonal migration, dispersal, nomadic, resident, or atypical, and the degree of wetland utilization for each individual was estimated. The overlap areas of population-level home ranges among capture sites were calculated for both the entire year and for individual seasons. Our results showed that approximately one-third of the individuals moved into and out of the wetland during the year as either seasonal migrants or individuals with atypical movement. Some of the individuals migrated to farmland areas outside the wetland (the farthest being 64 km away). Half of the individuals inhabited the wetland all or most of the year, i.e., 81–100% of their annual home range was within the wetland area. The movement patterns of these deer were classified not only as resident but also as seasonal migration, dispersal, nomadic, and atypical. Even among individuals captured at the same site, various seasonal movement patterns were identified. Annual population-level home ranges showed little to no overlap, and seasonal population-level home ranges were completely segregated among capture sites. Individual deer used the wetland either seasonally or year-round, and some populations inhabiting the wetland had sub-populations with different seasonal movement patterns, which need to be considered to achieve more effective ecosystem management including deer management in the wetland.

We evaluated the performance of global positioning system (GPS) collars deployed on free-ranging sika deer (Cervus nippon) to study their seasonal migration. We placed 21 GPS collars on 20 individual deer in the Shiranuka Hills, eastern Hokkaido, between March 2002 and March 2004. We could recover 17 (81.0%) collars and retrieved 20,278 location data from 13 collars on 12 individuals during 2002 and 2005. Tracking duration averaged 267 ± 17 (SE) days, fix success rate averaged 62.9% and ranged 34.4–81.8%. The proportion of 3-dimensional location averaged 46.4% and ranged 12.8–99.0%). We evaluated the fix success rates of three seasons (winter, migration period, and summer). In most cases, we found that the fix success rate in winter was significantly higher than that in summer. We consider the canopy cover of habitat affects the fix success rate of GPS collar. Although the GPS-based telemetry has some risks related to collar recovery and data retrieval, this method provides us a large volume of ...

Fifty-seven female sika deer (Cervus nippon yesoensis), captured at the wintering area in the Shiranuka Hills in eastern Hokkaido, Japan, were radio-tracked during 1997–2001 to examine the factors affecting seasonal migration at the individual-landscape level. Ten of the 57 deers migrated between low-altitude summer home ranges and intermediate-altitude winter home ranges (the upward migrants). Twenty-nine migrated between high-altitude summer home ranges and intermediate-altitude winter home ranges (the downward migrants). Twelve used the intermediate-altitude home ranges all year round (the non-migrants). The remaining six were unknown. The summer home ranges of deer were widely scattered over an area of 5734 km2. Migration distances ranged between 7.2 and 101.7 km. Deer showed high site fidelities to their seasonal home ranges. The upward migrants wintered in areas of less snow, higher quality of bamboo grass, and more coniferous cover than their summer home ranges. The downward migrants wintered in areas of less snow, higher quality of bamboo grass, higher winter temperature, and more southern slopes, but less coniferous cover than their summer home ranges. The non-migrants used year-round ranges with little snow, high quality of bamboo grass, and sufficient coniferous cover. We suggest that snow cover and bamboo grass are the factors affecting seasonal migration of the population and that coniferous cover is another factor for the upward migration.

The major factors affecting migration in large herbivores have been shown to be access to food resources and the risk of predation. Three migratory types of deer (resident, north migrant and east migrant) occur within a wintering female sika deer (Cervus nippon) population in eastern Hokkaido, Japan. We tested the hypothesis that north and east migrants feed on a higher quality diet than residents during summer, based on analyses of fecal nitrogen content. Fresh fecal pellets were collected in 18 summer ranges in the wintering area, northern area and eastern area between 1–5 August 2000. Fecal nitrogen content for all sampling sites was positively correlated with elevation, but was not correlated with distance from the wintering area. North migrants that inhabited higher (above 300 m elevation) summer ranges fed on a higher quality diet than residents. In contrast, the dietary quality of east migrants that migrated over a long distance and inhabited lower (below 300 m elevation) summer ranges was similar to that of residents. We conclude that east migrants may have gained significant benefit from the use of agricultural pastures with low population density conditions and without hunting; however, the recent population control program has reduced this benefit by avoiding the use of pasturelands.

Sika deer Cervus nippon in Hokkaido, Japan, have recovered from a population bottleneck about 120 years ago and their distribution has expanded rapidly in the last three decades. We tracked 53 radio-collared female sika deer, and obtained 4,430 locations during the 25-month study period from April 1997 to April 1999. We examined the seasonal distribution of female sika deer in relation to spatial landscape features (snow depth, vegetation, bamboo grass and roads) with a logistic regression model using a geographic information system database. We presented a population-landscape scale evaluation of sika deer habitat for summer and winter within the telemetry study area (TSA) using resource selection functions. We then extrapolated the model to the rest of eastern Hokkaido to discuss the seasonal migration for an expanding population. Most radio-collared sika deer (71%) moved between high-elevation summer and low-elevation winter ranges, whereas some (29%) moved between low-elevation summer and similar or high-elevation winter ranges. During winter, sika deer selected middle elevation habitats (200–400 m a.s.l.) with both a relatively low snow depth and the presence of coniferous and mixed forests. On the other hand, sika deer were widely distributed regardless of elevation during summer, although they were further from roads and less often in agricultural lands. Within the TSA, the suitable habitat was very limited during winter compared with during summer. Although migration from summer to winter ranges may depend on the abundance and distribution of suitable winter habitat at a landscape scale, migration from winter to summer ranges could not be explained from this study. Our approach is useful for understanding the relationships among seasonal habitat selection, seasonal migration and the expansion of the population.

Diverticular disease of the colon was detected in a female Japanese monkey by X-ray examination. The monkey was 15 years old and had been kept under captive conditions for nine years. Lack of appetite and activity, and constipation were observed. The monkey was given fiber-rich vegetables and wild plants, and its appetite and activity then improved. Based on a consideration of various factors, it is suggested that one possible cause of the diverticulosis in this case was a low dietary fiber intake.