Use of the Kaibab Lesson in Teaching Biology Christian C

A Textbook History: Use of the Kaibab Lesson in Teaching Biology Christian C. Young

T HE Kaibab deer ascended to national celebrity form. Rather than attempt to present science as a in the 1920s when their numbers increased series of discrete principles, however, many recent rapidly in the forest north of the Grand Canyon education reforms demand a more involved look in Arizona. The deer population then crashed as into the process of science (AAAS 1993). Scientific swiftly as it had grown. In the decades that followed, principles can be presented in their rightful place- scientific biologists used the popular story of the Kaibab deer as the products of diverse and hard-won Downloaded from http://online.ucpress.edu/abt/article-pdf/62/8/559/54015/4450978.pdf by guest on 26 September 2021 to demonstratethe adverse effect of predator control investigations, not as mysterious and isolated con- on prey populations. The deer gained notoriety in cepts invented or discovered by past geniuses. biology textbooks, illustratinga single scientific principle-what Aldo Leopold called a wildlife "irruption." Textbook use of the case fell off precipitously The Story of the Kaibab Deer after 1970 when ecologist Graeme Caughley noted In 1906, President Theodore Roosevelt established that the Kaibabirruption did not result from predator the Grand Canyon National Game Preserve on the control. In this article, I recount the once-familiar KaibabPlateau. His intention was to protect the mule tale of the Kaibabdeer and describe how this history deer from overhunting by humans and predation by is still relevant in biology classrooms, but for a natural enemies. He knew that human activities had different reason. I suggest that teachers can use the depleted wildlife species throughout the country, and history of the deer to teach students about the way only a few locations in the West still contained the ideas change. scientific numbers that had flourished a few decades earlier. Kaibab case stands as a prime illustration of The Roosevelt hoped that future generations of wildlife how history can more broadly inform the process of enthusiasts would be able to visit the KaibabPlateau and the relationship between science and science to witness an abundance of wildlife not remaining it no longer serves as an example society. Although elsewhere. of the direct link between human interference in The plateau is about 60 miles from north to south predator-preyrelations and the virtual destructionof and approximately45 miles wide. It is bordered by an entire deer the Kaibabdeer population population, the Grand Canyon on the south and east, by Kanab shifted dramaticallydue to a combinationof ecologi- Canyon on the west, and high desert on the north. factors that deserve examination. This approach cal These vast natural boundaries isolate the plateau a valuable introduction to studies of ecology offers (Figure 1). An estimated 4,000 deer lived in this area and conservation. when Roosevelt established the preserve, and he can also use the case to examine the way Teachers hoped that protection would increase their numbers use other historical examples that appear in they significantly. standard textbooks. Like so many of the "real- most The United States Forest Service administered the life" found in traditionalscience textbooks, examples new preserve as it had the surrounding forest lands the Kaibabcase represents a series of oversimplifica- since the 1890s. Ranchers grazed fewer domestic and exaggerations.These accumulateas a result tions animals there for a combinationof reasons, including of uncritical borrowing from one type of source degraded forage conditions and reduced permits from (primaryscientific publication) to another(specialized the Forest Service. The mandate of the preserve textbook) to yet another (general textbook). Eventu- prohibited all deer hunting on the plateau and at the ally, accurate knowledge about the development of same time exterminated"varmints" such as mountain scientific ideas is lost, and the ideas themselves are lions, bobcats, coyotes and wolves. Bounty hunters fixed in a more accessible but not always factual diligently tracked and killed mountain lions, which they viewed as the most significant enemy of the Christian C. Young is an Adjunct Professor in the Department deer. Wolves were already rare by 1900, having been of Natural Sciences at Cardinal Stritch University, 1316 N exterminated by ranchers before Astor St., Milwaukee, Wi 53202. e-mail: [email protected]. almost completely the turn of the century. Although local ranchersmay

THEKAIBAB LESSON 559 Utah Arizona Fredonia, Arizona n approximate boundary of KaibabPlateau

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Figure 1. Schematic map of the Kaibab Plateau, north of the Grand Canyon. not have favored the establishment of a game preserve esters based their estimates on very limited actual on lands where they formerly grazed large numbers counts, since the rugged country on and around the of livestock, they certainly supported the removal of plateau made complete censuses practically impossi- predatory animals that constantly threatened their ble (Mann 1941). cattle, sheep and horses on surrounding lands. In 1913, Roosevelt visited the plateau himself to Each year, local Forest Service officials estimated hunt mountain lions and noted the abundance of that there were more deer on the plateau than in deer (Roosevelt 1913). The Forest Service report for the previous year. These estimates served to provide that year chronicled Roosevelt's suggestion that some evidence of foresters' success in increasing the deer deer hunting be allowed. Hunting would require herd more than they reflect actual increases. Accord- a significant change in policy, however, since the ing to Forest Supervisor Walter Mann, previous for- proclamation that created the preserve prohibited

560 THEAMERICAN BIOLOGY TEACHER, VOLUME 62, NO. 8, OCTOBER2000 hunting, and no single individual or agency felt PRESERVED sufficiently confident of the situation to change the mandate of the preserve at that time (Mann 1941). When the newly formed National Park Service dedicated Grand Canyon National Park in 1919, jurisdiction of lands immediately north of the canyon rim I,~~~~~~~~0 went to the Park Service. This divided the preserve between Forest Service and National Park Service administration. The boundary between the two extended across the plateau from east to west about Larger organs 15 miles from the canyon. No barrier prevented the allow easier learning deer moving from park land to forest land within AMoredeveloped systemsfor /' j the preserve, and it soon became evident that differing management philosophies would lead to interagency advanced studies conflict over the deer. Reducedprices just in timefor back-to-school At about the same time this change in jurisdiction Downloaded from http://online.ucpress.edu/abt/article-pdf/62/8/559/54015/4450978.pdf by guest on 26 September 2021 took place, forest officials began to report potentially PIG 11-13", plain PGS1 1 13N $11.35 serious problems for the future of the deer. They PIG 11-13", double PGS1113.2N $14.95 suggested that the abundant deer might eventually deplete the plateau of edible vegetation, but neither PIG 13-15", plain PGS1 315N $14.55 the Forest Service nor the Park Service took any PIG 13-15", double PGS1315.2N $15.99 corrective action for a number of reasons. The primary reason for delay in preventing further NEBRASKA . population increase was quite simply that no one knew what action would be appropriate. The situation SCIENTIFIC did not appear disastrous in 1920, and foresters had 3823 LeavenworthStreet www.nebraskascientific.com no way of predicting how rapidly the deer herd was Omaha, NE 68105-1180 Fax: 402-346-2216 growing or even if the number of deer was still increasing. Moreover, officials in the Park Service were continually engineering new campaigns to entice more tourists to the Grand Canyon and hoped the rounding lands remained uncertain, and some argued deer on the North Rim would become a major attract- that there was no reason to consider reducing the ion in their own right. It seemed foolish to do deer herd because the vegetation on much of the anything until the scientists or wildlife experts under- plateau was still in excellent condition. At the request stood the situation more fully. of Forest Service officials, the Secretary of the U.S. Even if the federal government reached some agree- Department of Agriculture commissioned a study of ment on how deer within the preserve ought to be the plateau. This established the Kaibab Investigating managed, any action that involved actually killing Committee composed of biologists, foresters, conser- deer faced numerous obstacles. Those who favored vationists and hunters. hunting needed to establish the legality of hunting In the summer of 1924, the committee visited the in the preserve. More crucially, National Park Service Grand Canyon National Game Preserve to assess the policy strictly forbid hunting on its lands. In addition, condition of the deer and their food supply. Many state game departments held jurisdiction over hunting officials hoped the findings of this group would lead on all public and private land. Arizona became a to a new policy for the preserve. Those who hoped the state in 1912, and in the early 1920s the state govern- situation could be resolved quickly were disappointed ment favored tourism around the Grand Canyon when the experts did not reach agreement on a over hunting (Foster 1970). The Forest Service in number of key issues. Their estimates of the number particular recognized that its legal right to kill deer of deer ranged from 50,000 up to 100,000 (Figure 2). was questionable, at best. Hunting on the Kaibab Some reported that the food supply remained good, became legal only after years of law suits following others assessed it as fair, and still others thought it the arrest of unlicensed Forest Service hunters by was poor. They could not agree on any single solution state game wardens. to the problem. They suggested a range of options, Government officials surveyed the preserve repeat- from trapping and shipping deer elsewhere, to killing edly to assess the situation. Beginning in 1922, scien- half the herd outright. tists from the U.S. Bureau of Biological Survey agreed In the fall of 1924, the Forest Service chose a that the deer population required dramatic reduction. combination of all these options, starting with hunt- Other scientists who visited the plateau and sur- ing. They opened the plateau to hunters without the

THEKAIBAB LESSON 561 DEER ESTIMATES & REMOVAL A 100 N go9_0, | AoI T , M H 80 of A O ,0 L U 70 S 60 0 N A UN 50 il m D S 40 E 30

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Figure 2. After D. I. Rasmussen, EcologicalMonographs, 1941. Rasmussen offered a variety of data relating to the Kaibab deer population between 1906 and 1939. Among different estimates of the deer population, the highest was 100,000 deer in 1924. permission of the state of Arizona-leading to a officials predicted that deer would starve by the series of arrests-and without even notifying the thousands. While few carcasses of starved or frozen National Park Service of their intentions. The Forest deer were actually found, most visitors to the area Service tried its second option by organizing an effort the following spring reported seeing fewer deer than to drive some of the deer off the plateau, into the in previous years. Many supposed that undernour- Grand Canyon, across the Colorado River, and up ished deer became easy prey for coyotes or died in to the South Rim. Zane Grey, the famous Western rough terrain where no one ever found them. From writer, promoted and participated in this drive. this indirect and generally unreliable evidence, the Despite the assistance of local ranchers and Native deer herd's ruin became established. Americans, the attempt failed completely. Deer, as Reports of starvation and the much-reduced deer many experienced ranchers and naturalists well knew, population spread around the country in both scien- do not congregate and move in large groups like tific and popular literature. In the decade leading cattle or sheep. up to this dramatic climax, few observers commented This flurry of activity on the Kaibab Plateau brought specifically on the many factors that contributed to unprecedented fame to the emerging controversy the changing fortunes of the deer. Once the crisis there. Popular articles appeared in many of the nature became well known, many commentators focused on and sporting magazines of the time. The involvement the possible role of predatory animals. Critics of of a famous author, heads of several federal agencies, systematic predator control immediately drew con- and numerous well-known biologists captured the clusions from the sequence of events that began public's interest. with protection of deer from predators. Hindsight Because action to reduce the deer had been too made this example of the disruption of the "balance little and too late, many scientists and Forest Service of nature" painfully obvious to some. For others,

562 THEAMERICAN BIOLOGY TEACHER, VOLUME 62, NO. 8, OCTOBER2000 including those scientists who had seen conditions teachers began to describe irruptions without refer- on the Kaibab firsthand, such suggestions about the ence to any specific case. Even ecologists and wildlife relationship between predators and deer seemed quite biologists continue to debate the dynamics of predator tentative. Few of them, in fact, suggested ending and prey populations in actual practice (McCul- predator control. Everyone still wanted a wildlife lough 1997). preserve; unrestrained predators might make matters worse by killing the deer that survived starvation. Climate, habitat and livestock grazing undoubtedly Implications for Teaching Biology contributed to the problem, but the furor over preda- The Kaibab controversy now illustrates science as tors captured all the attention. a process, while earlierversions of the Kaibabstory- in the form of anecdotes with clearly defined start Interpretations of the Story and end points-obscured the continuing process of science. Teachers who want their students to see At this point, the facts necessary to illustrate the how disagreementsand uncertaintysometimes shape lesson of the Kaibab were all in place. The story had science will want to provide a richer account of their reached its climax, even if the eventual fate of the textbook examples. deer remained unknown. Later accounts of the lesson When students encounter the history of science in Downloaded from http://online.ucpress.edu/abt/article-pdf/62/8/559/54015/4450978.pdf by guest on 26 September 2021 ended with starving deer. Aldo Leopold later wrote this fashion, teachers ideally have an opportunity to that "just as a deer herd lives in mortal fear of its realize two important goals at once. First, students wolves, so does a mountain live in mortal fear of may quickly question, Why? Why did it take so long its deer" (Leopold 1949). This statement summarized for scientists to realize that the deer herd would an ecological principle concerning predator-prey rela- increase to a point of overabundance?Why did they tionships that became widely recognized. When wait to take action when they realized the problem? humans remove predators from an ecosystem, deer In order to respond to these questions, teachers can or some equivalent prey species will overrun moun- offer a lesson in understandingthe process of science. tains and rangelands (and more recently, suburban They can emphasize the importance of sometimes areas). Textbook accounts provided a quick denoue- embracing the perspective of the scientists and gov- ment to the Kaibab case that pointed to the stabiliza- emment officials, rather than only seeing from one's tion of the population. One widely used biology own point of view. Students need a certain amount textbook stated, "Thereafter the deer population con- of historicalsensitivity to recognize the many changes tinued to decline more slowly and by 1939 was down that took place in scientists' understanding of the to 10,000, living up to the capacity of the range, now natural world. Students can also start to see how seriously damaged by overcropping. With the range differentkinds of evidence are used to explain biologi- still deteriorating, starvation continued to kill more cal phenomena. Scientists in the past and scientists deer than the predators had" (Simpson et al. 1957, today look for consistent proof in support of their p. 655). It was enough to point out that scientists, theories, but new evidence often forces them to foresters, park rangers, game wardens, hunters and change their ideas. wildlife enthusiasts alike had learned the important lesson. Scientific studies of the deer population continued, however, as did the calls for evermore scientific INDEX TO ADVERTISERS expertise. The divided jurisdiction of the preserve AmericanAssociationfor NABTPublications Form ...... 614 remained problematic. In 1970, ecologist Graeme LaboratoryAnimal Science NABT Sust/OrgMembers .... 608 Caughley reviewed the tangled evidence of the lesson Foundation.555 NationalAcademyof and questioned the way two generations of textbook ASM Press...... 594 Sciences.617 authors had perpetuated Leopold's use of the Kaibab Bio-RadLaboratories ...... Cover3 NatureWaLk Magazine . 615 CarolinaBiological Supply NebraskaScientific 561 example. The evidence, Caughley suggested, was ...... Co...... Cover 4 PascoScientific .620 found wanting and the textbooks were just plain CyberEdinc ...... Insert PeregrnePublishers, Inc ...... 592 wrong in stating that predator control alone had DigitalFrog International 564 Phipps& Bird...... 587 caused the Kaibab irruption. He concluded that pred- ForrestT.Jones ...... 549 RutgersUniversity Press .--- 601 ators had a relatively minor influence on the deer Health-Science,Inc...... population. More significant were variations in habi- HolbrookTravel.557ments c ...... 62 MedlicalIst. 590 Swif tat caused by factors including climate, livestock Howard Hughes Itms,.Inc.621 HumneHuaeSoit PressPres ...... 8 TeamLabs . 547 Society 52TxsIsnnns...... Cover grazing, and changing federal and state wildlife poli- Leica Inc...... 552 2 Mcrosystems, TexasIstruments ...... Cover cies (Caughley 1970). NABTAffihiates... Vernier.Softwa . 551 After Caughley's critique, textbooks purged refer- NABTMembership Fomn ...... 577 ences to the Kaibab deer altogether. Authors and

THEKAIBAB LESSON 563 Second, teachers should find the history of science ing capacity." Students can examine this concept as useful in exploring the conceptual content of scientific a practical measure of ecological factors, rather than ideas. Although it would be incorrect to use the as a theoretical construct, represented simply as K lesson of the Kaibab simply to show that predators (Young 1998). Teachers can challenge students to regulate prey populations, the scientific work of natu- think about the importance of both density-dependent ralists who conducted research on the Kaibab Plateau (food, space, water, disease, predators) and density- helped establish principles of predator-prey relation- independent (severe weather, seasons, geological ships that are widely accepted today. Teachers can changes) factors. The Kaibab case illustrates the way describe those interactions by explaining that many all of these issues became significant as the population factors are involved in the population dynamics of grew, and also how human manipulations produced both predators and prey. These include habitat, cli- unexpected results. mate and weather, water and food availability, migra- Students can benefit from hearing a more elaborate tion patterns, and other causes of fluctuations, along history and thereby appreciate the development of with the sometimes unanticipated effects of human population biology. Rather than providing simplified activity. The Kaibab serves as a good example of historical anecdotes to accompany simplified scientific

this more elaborate lesson. principles, we should prefer to offer insightful cases Downloaded from http://online.ucpress.edu/abt/article-pdf/62/8/559/54015/4450978.pdf by guest on 26 September 2021 The Kaibab story also brings to light other concepts that exemplify diverse scientific understanding, in biology that remain central to both ecology and where process and content are intertwined. conservation, such as census-taking and sampling. As was the case in the 1920s, scientists rarely count Acknowledgments all the individuals in a population. In the field, scientists rely on estimates of the number of animals To several people who read and offered insightful found in complex habitats. Even with sophisticated comments on various drafts of this article, including techniques, they usually base estimates on samples Steve Fifield, Bruce Fall, Patti Soderberg, Rick Peifer, of the population. Scientists continue to find it diffi- Douglas Allchin and two anonymous reviewers, I cult to attain good measures of population density. offer many thanks. Assistance in obtaining materials Another concept involves the question of how vital to this account came from Teri Cleeland and many deer diverse habitats can support-their "carry- Barbara Stein. For additional advice on structuring this article I owe a great debt to John Beatty. References >->>l>- American Association for the Advancement of Science. >-le...... , ...... Z*>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.. -:3 ...... : ...i .:.....-: :.::-i:i:i R: R7: .E . : .E. :. E (1993). Benchmarksfor Science Literacy:Project 2061. New ...... York: Oxford University. Caughley, G. (1970). Eruption of ungulate populations, with emphasis on Himalayan Thar in New Zealand. Ecology, 51(1), 53-72. Foster, J.C. (1970). The deer of Kaibab: Federal-state conflict in Arizona. Arizona and the West, 12, 255-268. Leopold, A.S. (1949). A Sand County Almanac: With Essays on Conservationfrom Round River. Oxford: Oxford University. Mann, W.G. (1941). The Kaibab Deer: A Brief History and the Present Plan of Management. Williams, AZ: Kaibab National Forest. McCullough, D. (1997). Irruptive behavior in ungulates. In W.J. McShea, H.B. Underwood & J.H. Rappole (Eds.), The Science of Overabundance:Deer Ecology and Populationi .:...... ' Management (pp. 69-98). Washington, DC: Smithsonian Institution. Rasmussen, D.I. (1941). Biotic communities of the Kaibab Plateau, Arizona. Ecological Monographs, 11(3), 229-275. Roosevelt, T. (1913). A cougar hunt on the rim of the Grand Canyon. Outlook, 105, 259-266. Simpson, G.G., Pittendrigh, C.S. & Tiffany, L.H. (1957). Life: An Introduction to Biology. New York: Harcourt, Brace, and Company. Young, C.C. (1998). Defining the range: Carrying capacity in the history of wildlife biology and ecology. Journal of the History of Biology, 31(1), 61-83.

564 THEAMERICAN BIOLOGY TEACHER, VOLUME 62, NO. 8, OCTOBER2000