Sonoran Desert Summer

What could seem less inviting than summer in the desert? For most people, this prospect conjures up the image of relentless heat and parched earth; for biologist John Alcock, summer in Arizona's Sonoran Desert represents an opportunity to investigate the wide variety of life that flourishes in one of the most extreme environments in North America. "Only very special plants and animals can survive and reproduce in a place that may receive as little as six inches of rain in a year," observes Alcock, "a place where the temperature may rise above one hundred degrees each day for months on end." Yet he and other biologists have discovered here startling signs of life hidden in plain view under the summer sun:
- male digger bees compete to reach virgins underground during the early summer mating season;
- the round-tailed ground squirrel goes about its business, sounding alarm calls when danger threatens its kin;
- the big-jawed beetles Dendrobias mandibularis emerge in time to feast on saguaro fruits and to use their mandibles on rival males as well;
- Harris's hawks congregate in groups, showing their affinity for polyandry and communal hunting;
- robberflies mimic the appearance of the bees and wasps on which they prey;
- and peccaries reveal the adaptation of their reproductive cycle to the desert's seasonal rains. The book's 38 chapters introduce readers to these and other desert animals and plants, tracing the course of the season through activities as vibrant as mating rituals and as subtle as the gradual deterioration of a fallen saguaro cactus. Enhanced by the line drawings of Marilyn Hoff Stewart, Sonoran Desert Summer is both an account of how modern biology operates and a celebration of the beauty and diversity that can be found in even the most unpromising places.

John Alcock is Professor of Zoology at Arizona State University.