From eminent biologists like Alfred Russel Wallace and Charles Darwin to famous authors such as Rudyard Kipling in his "Just So Stories", many people have asked, "Why do zebras have stripes?" There are many explanations, but until now hardly any have been seriously addressed or even tested. In Zebra Stripes, Tim Caro takes readers through a decade of painstaking fieldwork examining the significance of black-and-white striping and, after systematically dismissing every hypothesis for these markings with new data, he arrives at a surprising conclusion: zebra markings are nature's defense against biting fly annoyance. Popular explanations for stripes range from camouflage to confusion of predators, social facilitation, and even temperature regulation. It is a serious challenge to test these proposals on large animals living in the wild, but using a combination of careful observations, simple field experiments, comparative information, and logic, Caro is able to weigh up the pros and cons of each idea. Eventually – driven by experiments showing that biting flies avoid landing on striped surfaces, observations that striping is most intense where biting flies are abundant, and knowledge of zebras' susceptibility to biting flies and vulnerability to the diseases that flies carry – Caro concludes that black-and-white stripes are an adaptation to thwart biting fly attack. Not just a tale of one scientist's quest to solve a classic mystery of biology, "Zebra Stripes" is also a testament to the tremendous value of longitudinal research in behavioral ecology, demonstrating how observation, experiment, and comparative research can together reshape our understanding of the natural world.
About the Author
Tim Caro is professor of wildlife biology at the University of California, Davis. He is also the author of "Cheetahs of the Serengeti Plains: Group Living in an Asocial Species" and "Antipredator Defenses in Birds and Mammals", both published by the University of Chicago Press, as well as "Conservation by Proxy: Indicator, Umbrella, Keystone, Flagship, and Other Surrogate Species".
Reviews
"Zebras are weird: the familiar shape of a horse packaged in a color scheme rarely seen beyond the coral reef. For that reason, there has been no shortage of theories for why the stripes evolved, with Rudyard Kipling's story of camouflage for an originally forest-dwelling beast by no means the most fanciful. Through his decades of fieldwork in Tanzania while building an enviable reputation as a world-leading behavioral ecologist and conservationist, the puzzle of zebra stripes has gnawed at professor Tim Caro. His book brings together a wealth of historical and scientific information, coupled with previously unpublished data, to suggest that an answer is at hand: deterring biting flies. This might sound like a Just So Story, but Caro's evidence is compelling, from his own comparative data showing an association across zebra races between stripiness and fly distribution, to experimental studies with painted targets, to mathematical modeling of the fly visual system. This book will interest any sensory or behavioral ecologist interested in animal coloration, but is also an insight into how to succeed in science: be curious, read widely, tolerate failure, and think broadly" – Innes Cuthill, University of Bristol
"A tour de force that characterizes the biology, morphology, physiology, and behavior of the equid genus as a starting point for examining in detail the unique features of its striped members. Caro clearly and succinctly presents the competing hypotheses put forward over the last one-hundred-fifty years (some even earlier) for why zebras are striped. The mix of methods with facts and interpretation is compelling, making what could be a complex and tedious presentation one that is clear, engaging, and to the point. 'Zebra Stripes' is an easy read, full of authoritative documentation from the literature bolstered by clever experiments (with Caro putting himself literally in a zebra's shoes – or actually a pelt), and constructed in a didactic, hypothetical, deductive way that gives it credibility. Its completeness and attention to detail will make it a must read" – Daniel I. Rubenstein, Princeton University
"'Zebra Stripes' is an attempt to answer the mysterious, longstanding, and popular question of why zebra have stripes. A personal journey in addition to a scientific appraisal of the evidence, it is highly original in its discussion of stripe hypotheses and its personal aspect; I am not aware of any work of comparable synthesis in depth or scope. It is comprehensive, up-to-date, and authoritative, and also contains a wealth of unpublished work and observations. Well written in a very readable style, interesting, and clear, 'Zebra Stripes' will unquestionably be of importance to any specialist in the field and of much interest to biologists more broadly, especially those interested in animal coloration, behavior, and evolution. Highly successful" – Martin Stevens, University of Exeter, author of "Cheats and Deceits: How Animals and Plants Exploit and Mislead"
