Mountain Wildlife - Mountain Geography: Physical and Human Dimensions - page 419

FIGURE 8.6 Generalized temperature gradient above and below a snow-covered surface in the sub-
arctic. High mountain environments are similar. Note that the lowest temperatures occur at the
snow-air interface, and temperatures increase rapidly within the snow down to the ground sur-
face. This demonstrates the excellent insulative qualities of snow. (After Pruitt 1970: 86.)
FIGURE 8.7 Various cold-blooded animals using the area underneath a rock as a microhabitat. The
greatly tempered environmental conditions in such locations allow the survival of species in areas
where surface conditions may be prohibitive. (After Mani 1962: 60.)
Cold-blooded animals—insects, reptiles, amphibians, and fish—all hibernate. Only
warm-blooded animals are able to remain active during winter. Some invertebrates
overwinter as eggs, while others hibernate as larvae, pupae, or adults. Species that nor-
mally complete their development in one season in the lowlands may take two or more
seasons at higher elevations (Alexander and Hilliard 1969; Coulson et al. 1976). But-
terflies in the Alps are known to overwinter as eggs in one generation and as pupae in