木曽駒ケ岳の哺乳動物に関する研究-4-木曽駒ケ岳東斜面低山帯上部におけるニホンカモシカの食性--採食痕の調査を中心に Studies on Mammals of the Mt. Kiso-Komagatake, Central Japan Alps IV. Food Habit of the Japanese Serow in Upper Part of Low Mountaineous Zone on Eastern Slope of the Mt. Kiso-Komagatake, with Special Reference to the Traces-Eaten
Investigation has been made from May 1975 to January 1977 in order to make clear the food habit of the Japanese serow, Capricornis crispus on eastern slope of the Mt. Kiso-Komagatake, where the University Forest in the Faculty of Agriculture, Shinshu University expands. The investigating area is a low temperate zone and is enveloped in natural forest in upper part of low mountaineous zone (1,200-1,600m above the sea level). Seasonal change of food plants was clear up by analyzing the plant traces eaten by the Japanese serow. This analysis didn't express quantitative estimation of plant eaten by the animal, but identification of plant, namely, qualitative list of plant species. Further, there was less data obtained from March to April and we were obliged to omit it. The results obtained were summarized as follows (1) The Japanese serow was used to bite tip of herbs, young trees and shrubs off and the animal seems not to be grazing herbivore, but browsing herbivore or snip feeder. (2) Total 189 plant species were listed up as the food of the Japanese serow, among them, 94 species (27 families) for herb ; 85 species (29 families) for broadleaf tree ; 7 species (2 families) for coniferous tree ; and 3 species (1 family) for bamboo grass, respectively. The number of species eaten by the Japanese serow reached to maximum in July (106 species) and thereafter down to minimum in November. (3) Number of plant species of herb and broad-leaf tree was divided into a half in each from May to November and the two plant groups should become themain food enough to feed at this time. While, ever-green coniferous tree and bamboo grass might be added to the two plant groups during winter from December to February. Number of herb species decreased suddenly and broad-leaf tree, therfore, might act an important role on food and percentage utility of broad-leaf reached on 83.1% at the time of February. On the other hand, the ever-green coniferous tree was down to 5% and 2% for bamboo grass. In the investigating area, there was so small amount of biomass for ever-green coniferous tree that the tree seemed to be a secondary food. (4) Plants feeded on each month throughout a year (but March and April could not be observed yet) were as follows : Hydrangea paniculata, H. cuspidata, H. macrophylla, Rubus kinashii, R. rnorifolius, Euonymus sieboldiana, Helwingia japonica, Clethra barbinervis, Sambucus sieboldiana and Viburnum furcatam. Above 10 species were all deciduous broad-leaf tree and the Japanese serow were used to feed on twings and leaf during spring to autumn and on twigs with winter bud. Moreover, plants feeded for the most part within a year were as follows Polygonum reynoutria, Clematis stans, Cirsium tanakae, Artemisia vulgaris, and Vitis coignetiae. It may be considered that these two sorts of plant species shall become a fundamental food resource for the Japanese serow in the area. (5) Petasites japonicus, Trillium tschonoskii, T. apetalon and Paris tetraphylla, which expand new green leaves to be the first to do other plants at the time of early spring may play a compensatory role upon many species of food plants feeded throughout a year. (6) Various species of herb and broad-leaf tree were feeded during summer, such as the plants mentioned (4) and Heracleum lanatum, Angelica multisecta, Cacaria hastata, Ainsliaea acerifolia, Eupatrium sachalinense, Elatostemma involuc-ratum and Boehmeria tricuspis as well. (7) Leaf of Petasites japonicus, fall down leaves of broad-leaf tree, dried herbs and nuts of Quercus crispula which were feeded during the late autumn must become a major food at the only short time of pass through autumn to winter. (8) Twigs and leaves of ever-green coniferous tree and bamboo grass which were feeded during only winter season (December to February), will supply for food in winter. In this period, the Japanese serow would usually not to be enough to feed the plant mentioned (4) and ever-green coniferous tree and bamboo grass seemed to be a suitable food for keeping hunger away. (9) Some poisonous plants were rearely feeded such as Scapolia japonica, Aco-nitum japonicum, Aquilegia buergeriana, Veratrum stamineum, Pieris elliptica, Aesculus turbinata and Buddleja insignis.(10) Plant species which did not remain traces eaten by the Japanese serow in the investigating area were as follows : Rhododendron degronianum, R. japonicum, Macleya cordata, Convallaria majalis, Shortia soldanelloides, Arisaema, Matteuccia struthiopteris, Blechnum niponicum etc.
信州大学農学部紀要 15(1), p47-79, 1978-07