“This book is an immediate classic. I had heard of it rumored for years. It is grand indeed and more than fulfilled my expectations.”

–Jim Harrison, author of Legends of the Fall and The River Swimmer

“Tracks and Shadows is a valuable, fascinating, very human book about the making of a field biologist. Harry Greene has lived the life of which I once dreamed: studying snakes. But there’s more here, much more, and what makes it all work is something not taught in herpetology class. This man can write.”

–David Quammen, author of Spillover and The Song of the Dodo

“With Tracks and Shadows, renowned field scientist Harry Greene masterfully–and poetically–examines the contradictions inherent in wild places that teem with both beauty and danger. In these stories, drawn from a life spent in the study of his beloved snakes, he reveals how an eminently humane scientist learned to find joy and peace by exploring the living world.”

–Mark W. Moffett, author of Adventures among Ants: A Global Safari with a Cast of Trillions

“Harry Greene shares the sting of death and the joy of life in Tracks and Shadows, but this brilliant book is also about the wonder of snakes, the beauty of studying natural history, and the importance of sharing a love of nature with humanity. It has something to teach every one of us.”

–Marty Crump, author of In Search of the Golden Frog and Headless Males Make Great Lovers

Harry W. Greene is the Stephen Weiss Presidential Fellow and Professor of Ecology and Evolutionary Biology at Cornell University and a recipient of the E.O. Wilson Award from the American Society of Naturalists. His book Snakes: The Evolution of Mystery in Nature (UC Press), won a PEN Literary Award and was a New York Times Notable Book.

Tracks and Shadows

FIELD BIOLOGY AS ART

By Harry W. Greene

UNIVERSITY OF CALIFORNIA PRESS

Copyright © 2013 The Regents of the University of California
All rights reserved.
ISBN: 978-0-520-23275-4

Contents

List of IllustrationsAcknowledgmentsPART ONE DESCENT WITH MODIFICATION1 • Tracks and Shadows2 • Naturalist3 • Nerd4 • Field Biologist5 • MedicPART TWO CONVERSING WITH SERPENTS6 • Graduate School7 • Hot Dry Places8 • Hot Wet Places9 • Giant Serpents10 • Venomous SerpentsPART THREE PRETTY IN SUNLIGHT11 • Friends12 • Loose Ends13 • Born-Again Predator14 • Field Biology as ArtNotesBibliographyIndex

CHAPTER 1

Tracks and Shadows

A TIMELY OLD QUOTE SIDLES around the two entwined themes of this book, myeccentric meditation on natural history. Writing from 1849 about Sierra Nevadastreams devastated by gold miners, journalist Bayard Taylor likened nature to “aprincess, fallen into the hands of robbers, who cut off her fingers for the sakeof the jewels she wears.” His brutal imagery frames a modern dilemma, becausealthough many people believe animals relocate when their habitats are destroyed,most organisms have nowhere to go. They will die rather than move. Worse yet,these losses are usually unseen and writ large all over the world, so we trulyare thieves, pillaging the future. My first theme, coming to grips with thispredicament, challenges everyone who cares about biodiversity—even if the effortto clarify what we want turns out to be a philosophical snake in the grass, morenuanced and elusive than I long supposed.

Taylor’s slashing tone also resonates with a second theme, the twists and turnsof my personal quest for wildness. Early on, as a curious youngster with ruralgrandparents, I discovered the seductive joys of nature study. From hornedlizards and livestock on a Texas farm to elephants and lions in zoos, I watchedand wondered. How can they eat only ants or hay or meat? Why do cow patties lookdifferent from horse dung, and do insects poop? I picked up a box turtle, peeredinto scarlet eyes as the head craned out, and asked my mother, “Where are theears?” In a child’s naive but earnest way, I yearned to reveal their secrets,and later, as I read and traveled widely, grander questions caught my attention:Why are some animals similar and others different? Why are there so many speciesin the tropics? And as the human population climbs on past seven billion, willfuture generations still marvel at nature?

There has followed a lifetime of chasing serpents, mostly real but occasionallymetaphorical. From earliest memories until age thirteen, I aspired to be acowboy or an explorer. Then I met a zoology professor and vowed to become anacademic. Soon I joined several organizations for herpetologists—folksinterested in amphibians and reptiles, informally called herpers—and beganpublishing in their journals, obsessed with biology. In college, because mylate-blooming, all-consuming social life required cash, I hired on at a localfuneral parlor as a mortician’s assistant and ambulance driver. Boy Scouttraining and vague notions of what the job would entail were my onlyqualifications, but I relished the excitement. It was only natural, then, thatafter graduation, having barely managed passing grades as a biology major, Iwould enlist as an army medic.

During my twenties I helped hundreds of ill and injured people, as well aswatched a dozen or so die from shootings, stabbings, and accidents. I stitchedup autopsied bodies, was bitten by an epileptic and squirted by severedarteries, had an assailant turn on me with a knife and listened uneasily tonearby gunfire. One night I tried to save a toddler with an allergic drugreaction, and forty-five years later, defenses softened by a good cabernet, Istill suffer the agony in her mother’s screams. There were happy endings, too—justdays after that little girl died I placed a squirming newborn at the breastof another young woman. Through it all, field biology was a respite, and by thetime thirty rolled around I was back on track for a Ph.D., studying snakeevolution and utterly clueless as to how those experiences might illuminate theissues with which this book is concerned.

A decade later and tenured at Berkeley, I’d lost an undergraduate advisor and alover to murders, a heart attack had dropped my father, and several friends haddied way too young. Their deaths provoked sensations of choking on explosionsand desperate grappling, as if I might strangle reality back to the future, andat times these people seemed oddly still present, like phantoms of amputatedlimbs. Personal frailty intruded too, during those middle years, in episodes I’dgladly never repeat. Some were exhilarating yet over so fast they remainedemotionally obscure, as when a high-speed collision spun our pickup truckthrough the rainy night into an Arizona pasture, or my foot bumped a CentralAmerican bushmaster, jolting the giant viper and me into mutually favorabledefensive responses. Other threats loomed more ominous with every endlessminute, like when we sat in speechless terror while our Aeroperú jet, one enginestreaming flames, circled back to Lima, or were confronted by angry, armed menin Uganda.

Little wonder, given those brushes with mortality, that desert writer Ed Abbey’sadmonition to “throw metaphysics to the dogs, I never heard a mountain lionbawling over the fate of his soul” beckons like a Buddhist koan. And perhapsit’s not surprising that natural-born killers inspired me beyond scientificjustification, as if confronting their deadly essence might solve more privateriddles. The upshot has been rewards akin to those that motivate artists:animals are the focus of my teaching and research, but fieldwork has also beencontemplative, inspiring me to pay attention and live more fully. The practiceof natural history, I have learned, fosters peace of mind.

Predators are linked in our psyches with wildness, perhaps all the more so forthose who study them. In Costa Rica fleeting shadows and strange soundsintrigued me, and because we found tracks and scats of jaguars I always hopedbut never expected to see one of those great hunters. Instead I poked throughdroppings and identified the drab remnants of lives briefly met, puzzled overlittle cloven hooves of collared peccaries and scythelike claws of three-toedsloths, the scaly feet and parchment-shelled eggs of green iguanas. Once abotanist led me to the bloody husk of a nine-banded armadillo, all that was leftof a fresh kill. And late at night, deep in the black woods, I thought aboutskull-piercing canines and meat-rasping tongues, tried to imagine the prey’sfine-tuned senses and gut-twitching anxieties. Do those wild-pig relativessqueal in their final moments, and would the lizards know what hit them? Could Iempathize with armadillos while contending with an empty belly or hungryyoungsters back in the den?

When a local entomologist grumbled, “Everybody wants to meet el tigre,” I chimedin about ecotourists seeking a quick nature fix, as if they were rushing throughthe Louvre for a peek at Mona Lisa. Better be content with turds and pugmarks, Imused, yearn for a glimpse of the great rainforest carnivore but settle forheightened awareness. Then, during one among countless nights searching forsnakes, a companion exclaimed, “Hey, a cat!”—it had bounded across the trail infront of him—and our lights swung into the forest. The jaguar squinted fromthirty feet away, all round head and broad shoulders, rosettes and long tail;just as suddenly, with not so much as a whispered paw on leaves, there were onlysmall palms and saplings in the headlamp beams. No more cat, as if it hadevaporated, and in those few seconds we more easily empathized with the Mayans,Olmecs, and others who have imbued forest creatures with mystical qualities.

Years later the memory of that animal surfaced when, with my wife, Kelly, andtwo Mexican friends, I backpacked from pine-oak forest that rims the four-thousand-foot-deep Barranca del Cobre (Copper Canyon) down into swelteringtropical thorn scrub along the Rio Urique. Fox scats and other carnivore signswere common along the canyon’s narrow game trails, so on the third day, when wesought permission to drink from a Tarahumara family’s spring, I inquired aboutpredators. A grizzled elder told us black bears raid their crops and they seetracks of mountain lions and jaguars. The mammals themselves are rarely visible,he added, and, as if by way of explanation, “Esos gatos caminan muy escondidos”—thosecats walk really hidden. Asked about rattlesnakes, the old man volunteeredonly that they’re common and bite people, leaving me wondering if his peopleregard las cascabeles as even more inscrutable than felids, and if, like me,they find dangerous snakes charismatic.

During my travels, focused on predators, I’ve come to believe that nature’s mostprofound lessons, like god and the devil, lurk in hard-won details. As a youthI’d envied George Schaller’s landmark studies of Serengeti lions but couldn’tconceive of similar research on the smaller, more secretive creatures thatcaptivated me. By the 1980s, though, I was collaborating with Tucson physicianDavid Hardy, and technology made it possible for us to implant tiny radiotransmitters in fifty black-tailed rattlesnakes. Over the course of nearly fivethousand encounters, we tracked those lovely black and yellow serpents inArizona’s Chiricahua Mountains, chronicling their hunting tactics and spying ontheir social lives. And throughout that experience, we kept asking ourselves aquestion that motivates many naturalists: What is it like to be a blacktail, orfor that matter a house wren or my dog Riley?

Almost six hundred observations of our most scrutinized rattler began in thefall of 1994, when we located her coiled with male 18 under the leaves of ayucca. While new female 21 was anesthetized Dave detected a meal by palpatingher abdomen, and weeks later a substantial midbody bulge indicated she ate againbefore entering a winter refuge in November. That next March she moved to a rocksquirrel’s abandoned burrow and in July delivered six babies. Female 21 remainedthere ten days, until the youngsters shed their natal skins and dispersed, thencrawled forty yards to a white-throated woodrat’s nest and hunted for the firsttime in nine months. She was courted by three males over the next two years,mated with male 27 prior to her 1998 litter, mated with male 26 prior tobirthing in 2000, and then skipped three years before her fourth litter.

We especially relished familiarity with individuals. Male 3 courted females butnever mated, whereas male 26, at about four feet long and three pounds ourlargest blacktail, had an enormous range and successfully courted severalfemales. Superfemale 21, as I later called my all-time favorite snake, was anexcellent hunter and good mother, plus she stayed out of trouble; over thecourse of twelve years she showed more meal bulges than any of the others,guarded four litters through their vulnerable first days, and never betrayed hercamouflage by rattling. Woodrats and rock squirrels are staple prey for thisspecies, but one morning our star gal struck a desert cottontail, followed thewounded rabbit’s chemical trail for more than two hours, and consumed it ninetyyards from the ambush site.

Watching the blacktails not only yielded generalizations about their biology butsometimes also left us grinning and shaking our heads in disbelief. One morningmale 41 crawled over the cobbles and dry leaves of a shady ravine, stoppedabruptly, and for thirteen minutes meticulously tongue-flicked a cliffchipmunk’s runway. Then he coiled, his head pointed at the little squirrel’spath. Because hunting-site selection had rarely been seen, we lingered,observing with binoculars from a few yards away. A dry fern was centered eightinches into the rattler’s strike zone, and after two minutes he extended thecrooked neck posture with which males fight over females, crushed theobstructing plant, and re-formed his ambush coil. I shot Dave a skeptical glanceand was reassured by his whispered, “He bent down that fern!” Later, after Ipublished those observations, Alberta naturalist Jonathan Wright wrote me ofhis astonishment at seeing a prairie rattlesnake tamp down grass around rodentburrows before setting up its ambush.

The surprisingly crafty responses of those snakes challenge clichés aboutminimal intelligence in reptiles, as well as pose questions some researchersbelieve are unanswerable, even silly: Could male 41 have conceptualized how aplant might thwart his quest for prey, even if the problem manifested itselfhours or even days later? Did he employ inferential reasoning and a move usuallyreserved for vanquishing rivals to solve what experimental psychologists call abarrier problem? What would a naive young male without combat experience havedone, and, since rattlers of the opposite sex don’t fight, how would superfemale21 have dealt with that fern? I am among those lucky folks for whom such puzzleskeep us headed outdoors, into the lives of others.

Nature has blessed me with many moments when my rumpled soul was naked and yet Ifelt unafraid. As we walked those cactus-studded ravines, gathering data andimagining the lives of blacktails, I turned from buried grief and self-absorption to more humble notions of our place in the cosmos. Studyingpredators, I contemplated violence without evil, death without tragedy, as ifwhen their fangs pierced another creature I might accept my own simmeringlosses. Other memories drift in too, of frogs singing and friends talking softlywhile high mountain mist enveloped our camp and dusk fell on an African swamp. Irecall afternoon shadows in the Mohave and how in that perfect stillness mystudents were mesmerized by bone fragments protruding from an old owl pellet,then shortly thereafter by the backlit, oversized ears of a kit fox napping byits burrow. Accompanied by kindred souls in such magical places, I wouldsometimes imagine us lions in the grass, tails twitching, and joy wouldoverwhelm even the most powerful sadness.

The essays that follow address twin themes, the first being how naturalhistorians transform curiosity into science and thereby help save species fromextinction. More than that, though, I aim to push into the poetry of fieldbiology, to emphasize the second, more personal theme and explore how natureeases our existential quandaries. I’ll begin by introducing the great explorersCharles Darwin and Alfred Russel Wallace, then bring in a venerable institutionand another extraordinarily accomplished naturalist, albeit less well known.Since early in the last century Berkeley’s Museum of Vertebrate Zoology hasplayed leadership roles in research, education, and conservation, and HenryFitch, my most influential teenage mentor, got his Ph.D. there in 1937. I’veenjoyed a life in some ways parallel to Henry’s and for twenty years wasemployed by the M.V.Z., so Part One combines our stories to illustrate howchildhood passions, chance, and opportunity shape adult trajectories.

Part Two moves from youthful obsessions to academic jobs, and thence intodeserts and rainforests, looking for snakes and other creatures. We’ll getacquainted with the nuts and bolts of field research and teaching, contrast theemotional impact of hot dry places with hot wet ones; we’ll learn some basics ofserpent biology and examine ways in which fear plays into relationships withlimbless reptiles. Part Three begins with reflections on friendship andhappiness, then delves into how an eighteenth-century philosopher’s aestheticsand Darwin’s theory of “descent with modification” can enhance appreciation forbiodiversity. We’ll also tackle troublesome notions like anthropomorphism andwilderness, and finally, backpacks brimming with questions, hit the trail afteranswers. My overarching claims are that organisms remain the core of biology,science plays key roles in conservation, and natural history offers anenlightened form of contentment.

With this book I’ve set out to praise sweeping dry plateaus and soggy tropicalfloodplains, as well as the black-tailed rattlesnakes, jaguars, and othercreatures that enliven them. More privately, though, right from the start, Iwanted to thank my heroes and explain some things to friends and loved ones; Iknew there would be disturbing undercurrents and thought they’d bestraightforward. Instead, Tracks and Shadows has unfolded as a complex,rewarding journey during which, after decades of studying predators, I becameone myself. Along the way, problems that seemed easy proved intractable.Nonetheless, by sharing my search for solutions, I aim to persuade others to getout there and learn more about themselves. By portraying field biology as art, Ihope to add another brief in defense of the wild.

CHAPTER 2

Naturalist

“DESCENT WITH MODIFICATION,” as Charles Darwin succinctly characterizedevolution, encapsulates two indisputable facts. First, all organisms shareancestors from whom they have descended. My beloved Riley comes from a long lineof Labrador retrievers, but his heritage extends back more than ten thousandyears to Eurasian gray wolves. My father’s lineage traces to Nathaniel Greene, aRevolutionary War general, and the most recent forebears I have in common withJesús Sigala, my Mexican Ph.D. student, lived in Europe, many centuries ago. Thesecond fact is that traits like Riley’s yellow coat color and the blue-gray hueof my eyes arose as mutations in individuals whose parents lacked them, andthose changes were inherited genetically by their offspring.

Darwin’s clever phrase thus accounts for similarities (inherited from parents)as well as differences (new traits in offspring) among individuals, and itsimplication, that strikingly dissimilar organisms share a family tree, extendsto all of life. Twisted-tooth narwhals, brightly splotched orcas, and theirEocene kin with small but obvious legs look more like each other than theyresemble sharks, reflecting joint heritage as cetaceans rather thancartilaginous fishes. White bats making tents from leaves, western pipistrellessheltering in crevices, and exquisitely preserved, sixty-million-year-old bat-wingedfossils resemble each other more than birds, just as expected ifchiropterans diversified from a single furry ancestor rather than a featheredreptile. And mammals as different as whales, bats, and people, whose hairycollective progenitor nursed young more than a hundred million years ago, sharemore similarities with each other than with sharks or birds.
(Continues…)Excerpted from Tracks and Shadows by Harry W. Greene. Copyright © 2013 The Regents of the University of California. Excerpted by permission of UNIVERSITY OF CALIFORNIA PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.