Inter-Desert Comparisons of Rodent Faunas

Abstract

Deserts share a number of properties. These are characterized by the contrasts in their combinations of environmental factors. Insolation may be extremely high, whereas moisture is scarce. Extreme environmental factors do not make life easy and restrict many animal and plant species to short periods in certain seasons when the combination of limiting abiotic factors have least effect. Deserts are arenas where Liebig’s law is manifested, and desert life is usually represented by species adapted to very specific conditions. Specific features of the desert environment promote adaptive responses in its inhabitants. Indeed, a broad spectrum of rodent adaptations to the harsh desert conditions can be recognized, from biochemical (e.g. Downs and Perrin 1991) through physiological (e.g. Weisserberg and Shkolnik 1994) to ecological (e.g. Goyal and Ghosh 1993) and behavioral (e.g. Randall 1993). In this chapter we will limit ourselves to consideration of ecological-behavioural adaptive responses only (the border between ecological and behavioural reactions is vague). The various biochemical and physiological adaptations of rodents to the desert environment have been thoroughly described and analyzed recently by Degen (1996) and we will therefore not consider these questions here.