Mountain Wildlife - Mountain Geography: Physical and Human Dimensions - page 421

FIGURE 8.8 A pika ( Ochotona princeps ) in typical rocky habitat. (U.S. National Park Service.)
Snails, frogs, and salamanders bury themselves in mud at the bottom of ponds or in
boggy areas, where they fall into a deathlike sleep that lasts until the snow and ice melt
in the spring. As with other life forms, the development of amphibians may be delayed
at higher altitudes. Thus, frogs in the Alps commonly pass the winter as tadpoles and
require an extra year for full development (Hesse et al. 1951). Many high mountain fish
hibernate once the ice forms over their heads and cuts off both their oxygen and food
supply. They commonly gather in small schools at the bottom of the lake or stream and
emit a protective ooze that enshrouds them all like a cloud. Fish living in shallow lakes
or streams that freeze down to the bottom may actually be encased in ice without suf-
fering damage.
Use of Microhabitats
Some species escape seasonal climatic extremes by burrowing or taking advantage of
microenvironments under snow, rocks, and vegetation. The small mammals that remain
active year round exhibit one of two basic types of behavior. In one group, the anim-
al stores up food for use during winter; in the other, foraging continues much as usu-
al. The first group includes pikas ( Ochotona spp.), deer mice ( Peromyscus spp.), wood
rats ( Neotoma spp.), various Eurasian hamsters (Cricetinae), and certain voles ( Micro-
tus spp.). These are all herbivores that gather bits of vegetation for their winter food.
They construct nests in well-drained ground or amid rocks, and depend heavily on the