Abstract: Discussed the wintering strategies of small herbivorous mammals inhabiting alpine area based on the data collected by the authors during 1985 1998 in the region of the Research Station of Alpine Meadow Ecosystem Acedemia Sinica. Observations were concentrated on the five most common species: Himalayan marmot ( Marmota himalayana)¡¯ plateau pika ( Ochotona curzoniae), Gansu pika (0. cansus), root vole (Microtus oeconomus). and plateau zokor (Myospalax baileyl)
Three main strategies to overwinter adopted by the species were found. Himalayan marmot was the only hibernator. So it needed not to storage food for winter and had a winter sleep from late September to the next middle April. Plateau zokor was the only subterranean rodent in non-hibernators. It usually started to store food individually for winter at the middle of September when juveniles was able to leave their mother to live separately. This activity ended in late October or early November when soils were frozen and food collection by burrowing was impossible. Root voles began to establish their food storage in late September. They stored their winter foods in underground storercums dug before so they could avoid the extreme cold exposure while using the foods. Gansu pikas exhibited haying behavior in late September. They harvested plants and cached them above ground at places with distance less than 1 meter from their burrow openings. Both root vole and gansu pika worked in herd when storing winter food. Plateau pika was found never to store food for winter.
Why did small herbivorous mammals in the alpine area adopt different wintering strategies? There are four reasons. First, high risk of predation might prevent small mammals from hibernating. Second, because fat deposits correlate to survival during hibernation and during post-hibernation activity that occurs before new food become available in the environment too small species could not adopt hibernation with the limitation of fat deposits in body. These two factors could explain why Himalayan marmot was the only hibernator. Third, lifestyle and physical conditions in environment could determine animals how to overwinter. For instance plateau zokor is a non-hibernating subterranean rodent, it lives on the underground parts of plants. If it dose not store enough food for winter it will die from starvation because foraging by burrowing in frozen soils is impossible. Fourth, animal's tolerance to cold, correlated to body size determines it's cold exposure limitations and thus it's way to overwinter. This can be used to explain the differences of wintering strategies adopted by plateau pika Gansu pika and root vole.
It can be concluded that wintering strategies of animals shaped in the long process of evolution and should be optimalized by nature selection. One can understand the profound evolution of animals by comparing their different ways to overwinter.

Key words: Small herbivorous mammals, Overwinter strategy

摘要： 利用多年工作积累的观察资料，讨论几种植食性小哺乳动物的越冬对策。其中，高原鼢鼠、甘肃鼠兔和根田鼠均贮存食物，以减少寒冷条件下的取食暴露。高原鼢鼠以个体为单位贮存和利用贮存食物，相互之间不协作；而两种地面活动的种类则可能以家庭为单位贮存和分享越冬食物。喜马拉雅旱獭体型较大，不贮存食物，它以冬眠方式越冬，这是一种对食
物依赖最小的方式。高原鼠兔，既不贮存食物，也不进入冬眠，而是主要靠增加身体产热能力来保持体温，抵御严寒。作者认为，动物自身的生理限制、生活方式、环境条件以及捕食风险等诸多因素的综合作用决定动物的越冬对策。

关键词: 植食性小哺乳动物, 越冬对策