Books, Naturally
Built for Speed: A Year in
the Life of Pronghorn
John A. Byers. 2003.
Harvard University Press, Cambridge, Massachusetts.
230 pp., clothbound. $24.95.
I’ve never seen a pronghorn burst across the western Great Plains at full tilt, but I once watched a cheetah sprint across the East African savanna to capture a gazelle. So swift was the cheetah that what I saw was a golden blur—just as the images of racing rust-colored pronghorn are blurred on the cover of John A. Byers’ elegant new book on one of our fastest land mammals. The link between pronghorn and cheetah goes deeper, however, than the similar affect their running has on our visual perception.
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| Pronghorn antelope. (Dave Menke, USFWS) |
Byers, who studies pronghorn on Montana’s National Bison Range, has an intriguing answer to the key question about these animals. Why do pronghorn run so fast—up to 60 miles an hour at peak performance and 45 miles an hour for miles on end—when no living Great Plains predator even approaches such speed? Byers believes that the pronghorn evolved its great speed and endurance in the past, when American cheetahs, racy, long-limbed hyenas, and other fearsome predators had them running for their lives. Now, with these animals extinct for about 10,000 years, pronghorn run from ghosts. As Byers writes in Built for Speed: A Year in the Life of Pronghorn, “They are survivors from another world, sculpted by natural selection in that world into running machines that in today’s environment blow the competition away.”
Such insights don’t come easily or quickly. To describe a year in the life of pronghorn with the depth of understanding and empathy revealed in this book, Byers spent 20 years watching them—collecting painstakingly detailed behavioral observations, catching and tagging each year’s crop of fawns, getting to know each and every individual pronghorn on the Bison Range, and tracking their fates throughout their fascinating, ghost-ridden lives.
It turns out much of pronghorn behavior, which Byers long found inexplicable, is left over from more dangerous days. From the time they are a few months old, pronghorn engage in endless dominance interactions. No sooner will a female recline, for instance, than another more dominant one will make her get up and move. That female, in turn, will displace another, and so on through the group, until finally everyone has found a place to recline in peace. But, “the result of the shuffle is that subordinate females usually are reclined on the edge of the group.” Why all this “snooty posturing?”
Byers tested all the hypotheses he could think of. Did dominant females feed more efficiently because they were displaced less often? No. Did they get a better quality of food? No. Fewer parasites because they were less stressed? No. Did they live longer or have more young? No and no. But they didn’t have to feed and rest on the edge of the group. And that would have been a real advantage in the past because animals on the edges are more apt to be picked off by predators than ones in the center.
Built for Speed gracefully weaves the story of pronghorn with Byers’ own journey of discovery via the scientific method: “The one-sentence question, followed by the one-sentence answer, is typical of a lot of science. A question pops into your head. You decide to address it. You work like a dog for 3 years, and then you have your short answer.”
But for Byers, this is a labor of love. His thorough enjoyment of learning to understand pronghorn, of puzzling over their behavior while enjoying their playful antics and mourning their losses, comes through on every page. Here he describes watching a mother that had just lost a fawn to a coyote—an all-too-frequent occurrence in Byers’ view: “. . . she moved restlessly, calling for the fawn and obviously looking for it. Her anxious casting about seemed to me a physical representation of the actions of our mind when we have suffered such a loss. Her actions were grief personified.”
While Byers focuses on pronghorn, he appreciates all of the wildlife that make their homes on the National Bison Range, from the bison and elk to meadowlarks, ruddy ducks, and grasshoppers. An astute and sensitive observer, his descriptions of these creatures are as apt and as lovely as those of pronghorn. He writes, for instance, “In mid-June, hundreds of meadowlark males singing in the grassland create a low flood of burbling that spreads across the prairie like the sheet of light that fireflies make at grass tops after a thunderstorm.”
As any book on wildlife must, Built for Speed ends with a plea for conservation and restoration. The once-great grasslands of the West are mostly gone, lost to agriculture over the last 150 years. Now, there is a growing movement to let a vast area of the Great Plains revert to grasslands, creating an area that’s been dubbed the “Buffalo Commons.” Byers attributes the appeal of this movement to the human affinity for grasslands—the environment in which our species came to be. He writes, “Like the pronghorn that act as if they feel the presence of the hyenas and big cats in their past, we continue to show our evolved habitat preferences in our emotional response to grassland.”
Anyone with an interest in the lives of wild animals
and how scientists come to understand them will find
Built for Speed a pleasure to read. It is beautifully
written and lucidly explains even the most difficult
science. Moreover, Byers tells his story with great
humor. It will also make an inspiring holiday gift for
a young person toying with a career involving animals.
—Susan Lumpkin
ZooGoer
32(6) 2003. Copyright 2003 Friends of the National Zoo.
All rights reserved.
