Condition Assessment of Sika Deer Population in Hyogo Prefecture: Characteristics of Reproduction, Food Habits and Nutritional Condition

Abstract

We analyzed fetal development, rumen contents, body fats, and organ mass of sika deer (Cervus nippon Temminck) as indices for sika deer conditions assessment in Hyogo Prefecture. All adult female sika deer were pregnant at the time of January to May. Estimated conception dates and fetal development were not delayed compared to the data of the 1980 s. Tree categories, evergreen broad-leaves, deciduous broad-leaves and graminoids made up the main diet, being more than 70% of rumen composition, year-round. These food items chosen by sika deer showed evidence of good quality food resources for sika deer in this area. However, kidney fat mass (KFM) and mandible marrow fat (MCF) indicated low levels through the year except for adult males in summer. These data suggested that characteristics of fat indices in sika deer did not indicate malnutrition but the trophic strategy of sika deer inhabiting west Japan. In evergreen forests sika deer can secure high quality food throughout the year, and hence they have no need to store fat accumulation. But these characteristics would be the defect for stochastic heavy snow accumulation or habitat deterioration because of lack of primary energy, fat accumulation. We recommended fetal development and rumen contents analysis to evaluate the condition status of the sika deer population in Hyogo.