The exigencies of life in the desert environment have resulted in the
se- lection of a diversity of adaptations, both morphological and
physiologi- cal, in the flora and fauna. At the same time, many plants
and most small animals are able not merely to exist but even to thrive
under desert conditions - mainly by avoiding thermal extremes and by the
refine- ment of pre-existing abilities to economise in water. In the
same way, the biotic interactions of the flora and fauna of the desert
do not involve many new principles. Nevertheless, conditions in arid
regions frequently do invoke refinements of the complex interrelations
between predators and their prey, parasites and their hosts, as well as
between herbivores and the plants upon which they feed. In this book, I
shall discuss not only such interactions and their feedback effects, but
also community processes and population dynamics in the desert. The
physical conditions of the desert that principally affect predators and
their prey are its openness and the paucity of cover. This is re-
stricted to scattered plants, occasional rocks, holes, and crevices in
the ground. Furthermore, nightfall does not confer relative
invisibility, as it does in many other ecobiomes, because of the clarity
of the atmosphere. The bright starlight of the desert renders nearby
objects visible even to the human eye, while an incandescent moon bathes
the empty landscape with a flood of silver light. Consequently, adaptive
coloration is func- tional at all hours of the day and night.