- 哺乳動物学雑誌: The Journal of the Mammalogical Society of Japan (ISSN:05460670)
- vol.3, no.5, pp.118-124, 1967-08-01 (Released:2010-08-25)
1) Feeding habits and nests of the Hokkaido squirrel, Sciurus vulgaris orientis THOMAS, were observed in a wind-shelter belt consisting of Picea excelsa LINK and Populus nigra L. var. italica MOENCH. and in a stand of Abies sachalinensis MAST. in the grounds (50m×110m) of a shrine at Futomi, Tôbetsu Town, Ishikari, Hokkaido. The width of the wind-shelter belt is 55m, the length 2km, and roads (about 10m in width) cross the woods at every 500 meters.2) One squirrel has resided in every area with a range of 55m×500m of the woods and in the grounds of the shrine, respectively. No data revealed that the animal went out to areas other than its own for hunting food.3) From fall to spring, cones and buds of P. excelsa and A. sachalinensis and mushrooms were eaten by this animal. The buds were extensively eaten from early winter to late May. There are two types of damage to the buds. One of them is the type where only the buds are cut off to eat, the other is that the animal cuts off a twig with buds and eats only the buds. The latter type of damage was observed only in severe cold mid-winter. In this case, however, slender twigs with a thickness of about 2mm are cut off, short (2cm-3cm), while thicker twigs with a diameter of 4mm-7mm are cut longer (15cm-30cm) .4) Nine complete nests and twenty abandoned old nests which were built on the upper base of side branches or at the crotched portion of trunks of P. excelsa and A. sachalinensis were observed. There was also a nest which was built in the roof of the shrine and a nest-hole in a tree trunk (P. nigra) . The nests which have an entrance at one side are usually elliptical in form and measure about 30cm in outer diameter, 25cm-30cm in depth, about 12cm in inner diameter of cavity, and about 7cm in depth of the cavity. The outside of the nests usually consists of P. excelsa or A. sachalinensis twigs and the cavity is lined by sasa bamboo leaves and bark of wild vines. The height of the nesting position ranges from 3.5m to 9.8m, with an average of 6.8m. One squirrel has one to three nests and around these there are 2-6 abandoned old nests. In many cases, the nests being used by one animal are situated 50m or more apart from each other in its home range.