Mountain Wildlife - Mountain Geography: Physical and Human Dimensions - page 404

FIGURE 8.2 Diagrammatic representation of reproductive cycles displayed among mountain insects.
(A) A normal one-year cycle with hibernation in the egg stage and adults emerging late in summer.
(B) A one-year cycle with hibernation in the larval stage and adults emerging in midsummer. (C) A
two-year cycle displayed among beetle at higher altitudes, with larval development taking place
in summer, relapsing into dormancy in winter, and final development occurring in the third year.
(D) An example of multiple-cycle reproduction in flies and mosquitoes where up to three or four
generations develop within the brief summer. (After Mani 1962: 118.)
Temperature may limit life by slowing the rate of development, and by reducing
metabolism and the rates of activity, fecundity, and reproduction (Andrewartha and
Birch 1954). The deer mouse ( Peromyscus maniculatus ) in the Sierra Nevada of Cali-
fornia produces three times as many young at 1,360 m (4,500 ft) as at 3,760 m (12,400
ft) (Dunmire 1960), primarily because low temperatures at high altitudes shorten the
breeding season. The same is true with birds: Alpine species are generally limited to