飼育されたトウホクノウサギ (Lepus brachyurus angustidens) の摂食量について

Abstract

野外実験柵内で夏・冬3羽ずつ成獣のトウホクノウサギを個別飼いして, 摂食量と排糞量 (いずれも乾燥重) の測定を行なった。餌は各季節に自生する植物 (夏季は野草, 冬季はササ・樹木の枝条) を与えた。その結果, 摂食量は夏季に100g/日程度, 冬季に100 - 200g/日であった。野生個体は冬季の餌が不足するために, 摂食量はもう少し少ないと思われる。排出所要日数を検討したところ, 野草は0. 5 - 2. 5日, ササ・枝条は0. 5 - 2日となり, 見かけの消化率 (水分をのぞく) は野草で31 - 53％, ササ・枝条で8 - 29％となった。実験期間をさらに長くとれば, より正確な数値が得られると考えている。

To know the mean of pellet number per hare per day, three adult hares were separately raised in the open field enclosed with fences for about a week in summer, and different three adults were similarly in winter. The food given in summer was various kinds of natural grasses and pasturages, and in winter it was apples in the first half, bamboo grass and some twigs in the second half (Table 1). The results were as follows; The mean of pellet number per hare per day was 271.0 ~ 365.7 pellets/day without very small ones. Amount of consumption was 60.3 ~ 152.7 g/day in summer, 30.2 ~ 213.4 g/day in winter, and amount of defecation was 33.7 ~ 107.0 g/day in summer, 22.1 ~ 106.9 g/day in winter respectively (Fig. 1, 2). It was presumed that the days from eating to excretion were 0.5 ~ 2.5 days in case of various natural grasses and pasturages (Fig. 3), 0.5 ~ 2.0 days in case of bamboo grass and twigs (Fig. 4).