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 nonmigrants). The remaining six were unknown. The summer home ranges of deer were widely scattered over an area of 5734 km 2 . 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 yearround 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.

Sika deer Cervus nippon in Hokkaido, Japan, have recovered from a popula tion bottleneck about 120 years ago and their distribution has expanded rapid ly 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 rela tion 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 east ern 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-e l e v a t i o n 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 rela tively low snow depth and the presence of coniferous and mixed forests. On the other hand, sika deer were widely distributed regardless of elevation during sum mer, 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 land scape 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 popu lation.

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.

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We examined fidelity to seasonal migration routes and seasonal ranges of 10 migratory female sika deer Cervus nippon yesoensis (9 adults and 1 fawn) in eastern Hokkaido, Japan (April 1997-May 2001. Six deer did not change migration routes among years and between fall and spring migrations. Three deer used different routes between fall and spring migrations, but did not change migration routes among years in each season. When some deer changed winter ranges in some years, these ranges were located along the migration routes. These findings do indicate that migratory female sika deer show high fidelity to migration routes.