UTMARK - tidsskrift for utmarksforskning
Special issue on applied ecology
http://www.utmark.org | Number 2b 2013
Peer reviewed article.
UTMARK - tidsskrift for utmarksforskning |
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Special issue on applied ecology |
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http://www.utmark.org | Number 2b 2013 |
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Peer reviewed article. |
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Applied ecology as a lifelong experience:
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| Vegard Gundersen | Norwegian Institute for Nature Research - NINA |
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| Morten Kraabøl | Norwegian Institute for Nature Research - NINA | |
Aldo Leopold’s lifelong professional experience with large predators proved that he completely changed his perception of their role in the ecosystem. In the early part of his career, while working as a forester in the partly undiscovered American Southwest, Leopold advocated extermination of large predators from the region, but he gradually changed his perception towards a statement that predators are essential to improve “stability, integrity and beauty of the community”. Leopold gradually realized that simple causality between predators and prey as well as one-coined focus on utilitarian values gives a far too simple picture of the complexity of an ecosystem. Leopold's views of perception and knowledge is inter-twisted and broadly understood within ethical and aesthetical terms as well as ecological science. A sustainable use of nature is not achieved unless holistic aspects including historical, ecological, ethical, and aesthetical perspectives are embodied in management practices. Today’s ecologists still struggle, as Leopold did during his whole life, in communicating the importance of vital ecosystem phenomena to the public. The book A Sand County Almanac represents the completion of a lifelong journey for Leopold, and provides a development of an ecological conscience by reaching a broad public in illuminating applied ecology through the narratives in the book, which is always connected to a particular place and landscape context.
Key words: : A Sand County Almanac, extermination, perception, attitude, wildlife management, game management, wolf
Aldo Leopold hadde gjennom hele sitt yrkesaktive liv forvaltningsoppgaver og forskning relatert til de store rovdyrene i USA og deres rolle i økosystemet. Det er derfor interessant å se nærmere på hvilke erfaringer han gjorde seg som observatør og forsker, og hvordan dette virket inn på hans endrede syn på de store rovdyrene gjennom sitt livsløp. Tidlig i karrieren jobbet han som skogbruker og kartla de siste urørte «hvite flekkene på kartet» i det sørvestlige USA. I denne perioden mente han at rovdyrene gjorde så stor skade på viltbestandene, og senere også husdyr, at de måtte utryddes. I hele sitt vitenskapelige og praktiske liv strevde han med å utdype dilemmaer omkring forholdet mellom mennesker og store rovdyr, og vi viser i denne artikkelen hvordan tvilen og diskusjonene rundt temaet har kommet til uttrykk i hans vitenskapelige produksjon. I hans siste år skrev han essay-samlingen «A Sand County Almanac» hvor han kom frem til en endelig konklusjon om at de store rovdyrene har en essensiell rolle i forhold til «stabilitet, integritet og estetikk i økosystemet». Leopold innså at enkle årsak-virkningsforhold mellom rovdyr og viltbestandene, så vel som ensidig fokus på nytteverdier i naturen, gir et altfor snevert bilde av helheten og kompleksiteten i økosystemene. Menneskets forhold og bruk av naturen, foregår alltid i et vektet samspill mellom etiske, estetiske og økologiske forhold. Det er først når man inntar en helhetlig tilnærming at man kan gjøre bærekraftige valg i forhold til økosystemenes funksjon og menneskers naturbruk. Økosystemene er komplekse, og Leopold strevde med å kommunisere økologiske problemstillinger til befolkningen, slik tilfellet også er i dag. Leopold lyktes imidlertid med å nå ut med denne kunnskapen etter sin død gjennom forfatterskapet «A Sand County Almanac». I denne mye omtalte essay-samlingen utviklet han en form for økologisk samvittighet som alltid var knyttet til det konkrete landskapet og det som skjer der menneskene bor og henter sitt levebrød.
Aldo Leopold (1887-1948) was influential in the development of modern environmental ethics and wilderness conservation (Meine 1988). His holistic eco-centric approach regarding pristine nature and wildlife preservation had a profound impact on the environmental movement. He emphasized biodiversity and ecological functionality, and was the founder of the science of wildlife management. It is of current interest for today’s nature managers, NGOs and others to gain insights to his radical change in perception towards large predators in a human-dominated landscape during his professional lifetime, ranging from early days initiation of extermination programs in several national forest areas, towards a recognition that large predators are essential for the “stability, integrity and beauty of the community”. In the essay Round River in “A Sand County Almanac” Leopold wrote: “Harmony with land is like harmony with a friend; you cannot cherish his right hand and chop off his left. That is to say, you cannot love game and hate predators. The land is one organism” (Leopold 1966). In our opinion, it is of great importance to maintain focus on a holistic and sustainable basis for nature management.
Aldo Leopold was a remarkable man. He was a craftsman as well as a professional forester who was able to see more than just the trees in a forest. He was also a conservationist and the first professional to advocate the field of wildlife management. His attraction is not only as an extraordinary naturalist of his time, but also because of his philosophical thinking, lyrical writings and impact on modern nature management (Meine 1988; Meine & Knight 1999; Knight & Riedel 2002). He elevated the developing field of ecology to include philosophy and environmental ethics in a brilliant manner by publishing timeless literature. 'A Sand County Almanac', first published in 1949, demonstrates his insight gained through a lifetime of experience from natural science and human-wildlife conflicts (Leopold 1966). Leopold was throughout life dealing with the dilemma between practical concrete experiences and theoretical abstract knowledge, for example concrete observations that predators take prey and the scientific general knowledge of the importance of predation for the prey population, later known as top-down effects. He was a forest manager who became one of the first Professors of Game Management in the United States. His practical experience greatly influenced his research and management work, which was always put in a given context, either pragmatic, realistic or practical; scientific ecological laws can never capture the individual detail that is connected to a particular place. The evolution of his work became more and more critical, qualitative and historic during his lifetime, culminating in the publication ‘A Sand County Almanac’. In this book he outlines a concept of land ethic based on specific and concrete descriptions of all the components in a landscape - in both a local and diverse landscape context. His essays included the spiritual and intuitive modes of perception in order to view nature as a whole community, for example communicated by the title of one of the most famous essay “Thinking like a mountain”. He taught that nature must be understood in a historical context. His tools, always sharp, can be viewed upon as extensions of his mind: eye, pencil, axe, shovel, dog, rifle and bow.
The issue of predator-prey relationships and the question of predator control ranges between practical experience like hunting and field work, and scientific knowledge of population dynamics and ecology. Leopold was a keen hunter his entire life and turned to bow hunting in the later part. From his outdoor experience he saw that the goshawk preyed upon quail and it was easy to deduce that the goshawk population regulated the quail population. At the beginning of Leopold's life there was limited ecological knowledge regarding the predator-prey relationship. However, during his lifetime the sum of his experience helped to put the predator control issue in a new light both practically and academically. He experienced that the predator-prey relationship was much more complex than earlier assumed, and also involved other aspects than pure utilitarian values. At that time conservationists were operating under the straightforward and simple assumption that elimination of top predators would make game plentiful. The essays in “A Sand County Almanac” provide a non-technical characterization of the trophic cascade where the removal of single species carries serious implications for the rest of the ecosystem. Leopold used the word "perception" for the skill to observe minutiae and connect this ability with a deeper ecological sensitivity and empathy toward the environment (Gundersen & Mäkinen 2009). Perception is something more than pure physical observations of different defined categories of nature, it include modes of ethical, aesthetical and ecological evaluation. Here is how Leopold himself describe perception: "Perception in short, cannot be purchased with either learned degrees or dollars; it grows at home as well as abroad, and he who has a little may use it to as good advantage as he who has much" (Leopold 1966, 292). Leopold meant that evolution, operated on more than the physical structure of organisms. It operated also on behaviour patterns and, among humans, on ethical norms and skills. Leopold’s attitudes towards predators illustrated this in a concrete matter.
In this paper we will investigate what kind of statements, arguments and meanings Leopold used in his scientific production during lifetime, and further try to identify key experiences and scientific knowledge acquisition that seemed to be important for his changing perception. A comprehensive review of his published literature is performed to review the story chronologically, and to provide a contextualized framework to understand Leopold's developing attitudes on predator-prey relationships and predator control as a tool to regulate game populations. Numerous books and discussion papers have been published based on Leopold’s life and writings (e.g. Errington 1948; Flader 1973; Allen 1987; Callicott 1987; 2000; Tanner 1987; Meine 1988; Flader & Callicott 1991; Babbitt 1994; Lorbiecki 1996; Knight 1996; Warfield 1999; Freyfogle 2004; Newton 2006; Lannoo 2010; Berkes et al. 2012), also including section about his perception of large predators. These papers clearly underline his impact on modern nature management. The idea of our paper is solely to discuss Leopold’s perception of large predators during his lifetime, and with special relevance for current controversial debates in the wake of increasing and/or reintroducing wolf population in Norway and other places. In addition, we provide some concluding remarks on the rather obstinate utilitarian attitudes that still characterize the debate on human-predator relationships, and call for a better integration of the increasing body of knowledge on these issues. Hopefully, this article will contribute to a broader foundation of perceptions upon which sustainable attitudes are allowed to be fertilized by updated and multidisciplinary knowledge.
His early days and at the frontier Aldo Leopold was born in Burlington, Iowa, U.S.A., in 1887 into an aristocratic milieu. He got his love of the outdoors from his father, Carl Leopold. Long before federal law prohibited hunting during the nesting season, Carl concluded that it was wrong to do so and ended his hunting in winter, an epoch-making lesson in sportsmanship for Aldo. Aldo had no patience for people with bad intentions or unethical behaviour. In school he was reputed to be a perfectionist. Early in his childhood, Aldo had a memorable trip to Gilbert Ranch in Montana and later he always remembered this area as wilderness. As a boy, Aldo developed a lively interest in field ornithology and natural history. After his schooling in Burlington, then Lawrenceville Prep in New Jersey and the Shefield Scientific School at Yale, he enrolled in the Yale Forestry School, the first graduate program in forestry in the U.S. He graduated with a Master degree in 1909.
The U.S. Forest Service had just recently been established, and an elite group of forestry graduates from Yale's program were hired. Aldo Leopold was among them. He started in 1909 to survey the newly established Apache National Forest in New Mexico. This forested land belonged to the Apache tribe until 1886 when Geronimo and his people were forcibly removed. The forests were virgin wilderness with large populations of grizzlies (Ursus arctos horribilis), wolves (Canis lupus lupus) and mountain lions (Puma concolor). To Leopold, an urban Midwesterner, these enormous open areas engendered feelings of hope, adventure and freedom. The first genuine wilderness he had ever known had an immeasurable impact on him (Sweet 2002). Leopold bought a rope, a 0.30-30 carbine, a revolver, boots, batwing chaps and a hat big enough to shade his horse too. Off he rode as head of the survey team.
Two important events during his time in Apache National Forest had enduring, although not immediate, impact on Leopold's attitude towards predators (Sweet 2002). The first was that in 1910 the "outlaw" bear "Big Foot" lived on the slopes of the Escudilla Mountain in New Mexico, and his presence flavoured the ranch culture in the area. The grizzly symbolized the endurance of the wild frontier. In the spring of 1911 a bounty hunter decided to track and kill this bear. With the killing of Big Foot, presumably the last grizzly in the vicinity, the area was no longer truly wild and the human inhabitants were no longer frontiers-people. Thirty years later, Leopold wrote, "Escudilla still hangs on the horizon, but when you see it you no longer think of bear. It's only a mountain now" (Leopold 1966, 145).
Two years earlier Leopold led a timber survey along the Arizona-New Mexico border. One afternoon while the crew was having lunch on high rimrock, a female wolf and her pups came out of the woods and began crossing the river far below. Meine (1988, 94) describes the event: "…, they saw that it was a wolf…emerged from the streamside willows to greet the old wolf. The men went to their rifles, and hastily blasted away at the wolves from the rock above…The wolf was still alive, but unable to move. Leopold saw in the eyes of the wolf what he would describe years later as "a fierce green fire"…the wolf gnashed out and grabbed the rifle butt in its teeth. The men backed off. As they watched from a distance, the green fire died, but not before it had burned the moment into Leopold's psyche". Without these events he would not have been able to write his self-critical essay ‘Thinking Like a Mountain’ three decades later (Leopold 1966).
After gaining experience his first year working in Apache and Gila National Forests in New-Mexico, the next year he proclaimed was "one of my best summers". In the years ahead, 1911-1913, he became a more reflective man. His work entailed administering grazing licenses, dealing with the overgrazing problem and trying to regulate the sheep population in Carson National Forest in northern New Mexico. By the age of twenty-five Leopold was appointed supervisor of Carson National Forest. Carson National Forest had been utilized by farmers for a long time, and predators were very scarce and the deer population was low. Leopold's field experience in both Apache and Gila National Forests became very important for his later attitudes and writing. He was given the opportunity to explore and tame one of the last remaining wilderness areas in the U.S.A., the manifest destiny. Later on he was successful in granting Gila in New Mexico status as the first wilderness area in the U.S. Hornaday`s book, ‘Our Vanishing Wild Life’ (Hornaday 1913) dealt with threatened species, and was a very influential book on Leopold. Around this time, an Apache friend of him had killed 4 bobcats (Lynx rufus) and 4 mountain lions. Leopold applauded this in the journal Pine Cone (Leopold 1915). The year 1915 was a turning point in Leopold's life as he focused more on conservation issues and less on forestry. In regard to conservation in the years to come Leopold never mentions predators as species that should be protected (Leopold 1920a). He was active in the New Mexico Game Protective Association (NMGPA). Their first goal was to establish hunting laws and regulations and secondly to design a network of game refuges. A third goal was predator control with the following resolution: "Urging and fostering by all possible means a systematic campaign against predatory animals destructive to game and livestock". This resolution meant in practice an extermination of many species. Predators had few if any supporters in the West, illustrated by the fact that even Hornaday did not question this hunting practice. Leopold was not among the worst supporters of this policy but he often used words such as vermin, and varmint: "It is going to take patience and money to catch the last wolf or lion in New Mexico. But the last one must be caught before the job can be called fully successful" (Leopold 1920b). Leopold was not hunting predators himself but supported clean-up of varmints (Gibbons 1981).
The ecology and understanding of game population dynamics was not very developed at that time. The knowledge had to be based on personal experience and observation. It was easy to draw conclusions from what one saw in a specific context or environment, but these conclusions were not often the same as an ecological law. Wildlife populations, already thin, seemed to be further decreasing, and Leopold, with a hunter's heart, knew that without wildlife there was no wilderness. For Leopold it was easy to "see" the competitors for game (Leopold 1915). Four years later he had a similar statement: "The advisability of controlling vermin is plain common sense, which nobody will seriously question" (Leopold 1919). Leopold's intuitive sense of phenomena in the natural world had always been a part of his psyche, and could at the present time be summarized as follows: to increase game, we kill our competitors, the predators. So, after we kill off our competitors for the game, the number of game could increase, and finally the hunting pressure grew.
In 1919 Leopold occupied the second highest position in the district as Chief of Operations. By 1920 the wolf was close to extinction in Arizona and New Mexico. Leopold gave a lecture at the Sixth American Game Conference about predator control in the West: "as the work progresses, the remaining animals become fewer, more sophisticated, and more expensive to catch" (Leopold 1920b). A similar attitude can be stated in this quotation: "No plans for game refuges or regulation of kill will get us anywhere unless these lions are cleaned out" (Leopold 1920a). During the period of 1919-1922 Leopold was active with NMGPA. He was now dealing with the relationship between overgrazing due to high deer population (because of less predators) and fewer forest fires (due to less groundcover). His attitude toward predators and forest fires was similar: "Fires were to the forests what wolves were to game and livestock - natural agents of destruction that had to be eliminated at all costs" (Meine 1988, 217).
Leopold's experiences in the West made him sensitive to the relation between cause - and - effect in nature, and these were experiences that he might never have gained elsewhere. He started out in 1909 in vast wilderness with strong predator populations and by the time he left in 1924 the wilderness was much smaller and the predator populations close to extinction. When Leopold left the West in 1924 you can see early signs of his shift in attitude toward predators and he started to question the effects of predator control. This last quote from this period could however be an open question about a change in his attitude: "There must exist in the public mind that fundamental respect for living things and that fundamental aversion to unjustifiable killing and to unnecessary ugliness which in all lands and all times has been a necessary foundation for good morals and good taste" (Leopold 1923).
Leopold described this simple theory of predator-prey relationships: "thought that fewer wolves meant more deer, that no wolves would mean hunter's paradise". His experience in Carson National Forest can be stated as follows: we have killed our predators to favour game and livestock but the deer population have become a competitor to the livestock. We then had to regulate the deer population by hunting so there will be more grass for our livestock. These systems of predator control and regulation instigated other problems like soil erosion and overgrazing by livestock. Leopold started thinking in a new direction since he realized that the predator-prey relationship was not as simple as he first thought (Leopold 1925). After leaving the West for a new job, he headed back to Burlington in Iowa and had some disappointing years working with the Forest Services Forest Products Laboratory in Madison, Wisconsin. Leopold then set out across the upper mid-western U.S. to survey the wildlife conditions there. He had contact with researchers in Kaibab National Forest in Arizona who were investigating the mule deer population. Leopold knew the Kaibab National Forest well after working on conservation plans for the nearby Grand Canyon. The deer population in this area was an example of one of the most mismanaged game populations ever. The game had been protected from hunting since 1905 and the population had increased dramatically as a result. Concurrently the elimination of predators started and thousands of coyotes, lions, bobcats and wolves were killed. The hunters and forest service managers did not succeed in regulating the deer population and it grew exponentially above the area’s carrying capacity. Consequently, it collapsed from starvation and disease during the winter of 1925-1926, as verified by Binkley et al. (2006). This final result of game population control led Leopold to think anew. He realized there was a need for new ecological insights. Thus Leopold had to rethink the strategy of eliminating predators. This was the first step in reconsidering the well-established slogan that "a good predator is a dead one". Even though Leopold still used the negative word "vermin" in his notes and journals, something new was in the air. At the annual American Game Conference in 1924 he stated: "We have learned…that game, to be successfully conserved, must be positively produced, rather than merely negatively protected…We have learned that game is a crop, which nature will grow and grow abundantly, provided only we furnish the seed and a suitable environment". This meant that studies in game management were strongly focused on dissemination factors in a population (hunting, predation, starvation, disease, parasites), while Leopold wanted to focus more on the welfare factors (food, water, cover and other factors). By 1927 Leopold had modified his view of predators: "…we have overdone control on some of the National Forests, especially with respect to bear" (Meine 1988, 256).
Leopold received reports that the deer situation in Gila National Forest in New Mexico was getting worse, similar to the Kaibab area in Arizona. The management solution in Gila was to increase the hunting pressure by building roads into the wilderness, which saddened Leopold. The elimination of predators was now contributing to the destruction of the wilderness! On a field trip to Missouri, he experienced a different relationship to predators. The red fox was viewed both as a hunting trophy and as a predator. In some places they wanted to hunt down fox, yet in other places they were ashamed to hunt fox.
Leopold changed his theory, which was originally to hunt down predators to extinction at all cost. By 1925 he said that some of the large predator species could be saved in the name of science. In 1926-1927 he was concerned about the predator situation, and an example being grizzly bears: "A goose is like a grizzly, his mere presence can add a sort of flavor to a whole country" (Leopold 1926). By 1929-30, Leopold stated that the mountain lion probably had a role in regulating deer population and probably management policy could gain by increasing their population. He advocated for more focus to be put on smaller predators: "What kinds and numbers of predatory species can be allowed to inhabit (a quail range)" (Leopold 1929), and "…Future predator control must be localized and discriminate…There should probably, in most localities, be more control of small and perhaps less of large predators" (Leopold 1930a). And finally in 1930 he came up with this conclusion: "No predatory species should be exterminated over large areas…Rare predatory species, or species of narrow distribution and exceptional biological interest or aesthetical value should not be subjected to control" (Leopold 1930b).
Leopold published the book ‘Report on a Game Survey of the North Central States’ in 1931. Some researchers and managers were critical as the book did not include the predators, and others criticized it for only focusing on game species when there were many species threatened by extinction. It is easy to understand the inner conflict for Leopold who wore many hats: aesthete, sportsman, conservationist, academic, outdoorsman, manager and observer. For him especially, the dilemma of predator control was difficult to balance. He criticized European predator policy as being too empirical (Leopold 1931a). New research showed that predators had a less significant role in regulating game species than previously thought (e.g. Murie’s elk-coyote relationship and Errington’s quail-hawk relationship). Now, other factors such as vegetation cover and food were considered in the equation. Leopold realized this: "The idea of controlling environment is the fundamental thing for game management to contribute to the conservation movement. Shooting and other aspects of game utilization are simply things which become possible when environments are kept favourable" (Leopold 1931b). His famous book ‘Game Management’ was published in 1933 and the chapter on predator control can be seen as a reflection on Errington's quail-hawk research conclusions (Errington 1932). Leopold defined game management as "the art of making land produce sustained annual crops of wild game for recreational use". The goal was to identify the factors that limited game populations and then to manipulate them. The book ‘Game Management’ had in general an objective scientific view of predators (Leopold 1933), but included aesthetic aspects of the predators, only in a conflict context: "…and the elimination of predators as an aesthetically valuable part of the fauna". His book reflected a pragmatic and realistic view of the world. The depressed U.S. economy slowed research to a halt. Leopold persevered to study two factions in wildlife conservation; the "wild-lifer" view of wildlife as having aesthetic and recreational value versus the "gunpowder" faction who only wanted to hunt. In “Game Management” it is statements of Leopold`s attitudes towards predators at that time: "…merely one of courage to protect one's own interests, and that all doubters and protesters are merely chicken-hearted" (Leopold 1933). Leopold wanted greater harmony among conservationists. In pure frustration he started to study the issue from sociological and philosophical perspectives. His thinking led to this conclusion in his essay "A Taste for Country": "That wildlife is merely something to shoot at or look at is the grossest of fallacies. It often represents the difference between rich country and mere land" (Leopold 1966, 178).
Leopold was one of the first contributors to game management policy in the U.S. Leopold felt that the focus had been wrong or at least that there had been too much focus on predator control, and thereby disregarding other factors regulating game populations (Leopold 1932). From a philosophical viewpoint he at least realized that the killing of predators was a manipulation of a natural system in order to serve only human self-interest.
Early in the 1920s Leopold already questioned the extermination of grizzly bears. For Leopold the grizzly was the first species that exemplified that something was wrong. He used the grizzly bear as an example to clarify his position. Therefore, Leopold's writings about the grizzly are succinct and directly to the point compared to his writing about other large predators like gray wolves, mountain lions and lynx (Leopold 1936a, 1944a). The grizzlies were common in America before its settlement and they became for Leopold a symbol of the changing land and nation. Leopold also used scientific argument about the abundance of unique species and their evolutionary adaptation to the local environment (Leopold 1936a, 1942). The grizzly was not a major predator of game but preyed on ranchers’ sheep and cows (Leopold 1936c). After 1935 Leopold's writings about the grizzly bear became more qualitative and poetic (Leopold 1938c, 1040). His final conclusion was that the grizzly population had been mismanaged because the National Park system and other protected areas were too small in size for the range of the grizzly bear (Leopold 1966, 277).
Leopold became a professor at the University of Wisconsin in the year 1933, and became the first Professor of Game Management in the United States. At this time Leopold was still thinking of management in utilitarian terms and that the ultimate goal was to produce valuable commodities: timber, deer, or other wildlife. He thought that you could learn how the ecosystem functioned and then manipulate it in order to control it in the public interest. This viewpoint is in his book ‘Game Management’ (1933), which was an important textbook in the field of game management for decades and still is. Today, ‘Game Management’ have been read by many researchers and managers as an aesthetic book, but its basic concept is still the utilitarian view of nature, as found in the roots of Yale Forestry School as well as in the roots of the early U.S. Forest Service. The fundamental purpose of game management for Leopold was to change in the mid-to-late 1930s. He became interested in, not just game species, but all wildlife and land as an ecological organism. In 1938, he started to sign his letters as Professor of Wildlife Management instead of the previous Professor of Game Management.
The years of 1935-36 were memorable for Leopold - a trip to Germany, acquiring some land in Wisconsin and hunting trips to wilderness areas in Mexico. The change in Leopold's thinking occurred quite suddenly and was most probably related to three personal experiences.
The first experience occurred during his trip to Germany in 1935 where he went to study game management and forestry. There he found a system that was much too artificial for his taste. He began to realize that the opportunity still existed to manage land in a much more natural manner in the U. S. (Leopold 1936b). The German people loved hunting and to experience game but centuries of predator control had eliminated large predators, owls were almost non-existent and other predatory bird species were much less numerous than they should have been. He further learned that: "(In Germany) the culling function of predators seems to be universally recognized as a biotic necessity. Will this happy day come to America before, or after, our magnificent predators are gone?" (Leopold 1934). The trip to Germany was to become an important source of reference for him (Leopold 1936d). In his 1939 article A biotic land of view, Leopold stated that the Germans; "In their new Dauerwald the hard-headed Germans are now propagating owls, woodpeckers, titmice, goshawks, and other useless wildlife" (Leopold 1939a). Leopold used the word "useless" to describe the positive potential of restoration (Leopold 1939a). He experienced how difficult it was to predict the value of the land for the future: "Professor Weaver proposes that we use prairie flowers to reflocculate the wasting soil of the dust bowl; who knows for what purpose cranes and condors, otters and grizzlies may some day be used?" (Leopold 1939a).
The second experience was the acquisition of his own land area, which he and his family termed "the shack" on the Wisconsin River. Here he started to restore a worn-out farm to some degree of ecological integrity. He thought he knew exactly what to do but the land did not always respond as he expected. This instilled a sense of humility in him because he realized he did not have control of this limited landscape. At best, he might be able to nudge it one way or another. The shack was teaching him about the harmony of land that would influence his later thinking and writing about land ethics (Leopold 1938c). Of that reason the shack can be seen as an example of his experience on a small scale as he took daily notes of what he saw: "Some Sunday in January the tracking is good, I like to stroll over my acres and make mental note of the birds and mammals whose sign ought to be there, but isn't. One appreciates what is left only after realizing how much has already disappeared" (Leopold 1939b).
The third experience in the mid-1930s involved two hunting trips, one of them with his brother Carl and his son Starker to northern Mexico in the Sierra Madre of northern Chihuahua along the Rio Gavilan. These two trips were among his best bow hunting experiences. They saw more than 250 deer but did not shoot anything; "an abundant game population thriving in the midst of its natural enemies", and he encouraged "those who habitually ascribe all game scarcity to predators or who prescribe predator control as the first and inevitable step in all game management" to re-examine their premises (Leopold 1937a). They saw wolf tracks, a real sign of wilderness, and he was inspired to write Song of the Gavilan, which is about the howls of wolves from Gavilan. This area was unsettled because of bandit gangs along the border and conflict between the Apache Indians and the Mexican populace. He realized that this was a healthy ecosystem because there was still a healthy population of wolves and mountain lions predating on the deer (coyotes were rare) and yet the deer were thriving (Leopold 1937a). In less than a year he had witnessed two extremes along a scale of man’s relationship to land. First the exploited and densely populated Germany and second the wilderness in Sierra Madre. It was in Sierra Madre he first realized that the land could be viewed as an organism: "…first clearly realized that land is an organism, that all my life I had seen only sick land, whereas here was a biota still in perfect aboriginal health. The term "unspoiled wilderness" took a new meaning" (Leopold 1947 in Knight & Riedel 2002, 113).
From the beginning Leopold's writing contained elements about the ethical, the aesthetic sense and his love of the land and wildlife. The basis of his writing was that if you take care of the basic commodities, other less economically valuable elements would also be taken care of. The aesthetic aspect was thus always there in his writing but in a secondary way. In his writing after the mid-1930s it is obvious that it became clear to Leopold that the concept of land as a whole was imperative to gain sustainable management practices. Leopold wrote and talked increasingly about land health in terms of restoration instead of production of commodities. There are examples that Leopold took direct action against some forms of predator hunting. In 1935, the president of the National Rifle Association wrote an article about eagle hunting in Alaska and he called it "the purest of all rifle sports" for "we gun enthusiasts". Leopold criticized this in a letter and admitted, contrary to his own earlier writings, that this was not sportsmanlike hunting. In the public eye, this type of hunting also drew protest.
Leopold used different arguments that questioned the extermination of predators. First, he admitted that the focus had been wrong (Leopold 1937b). New ecological knowledge paid more attention to habitat destruction and direct factors such as food, water and groundcover. It was also at this point clearer to him that predators could have a welfare role in the ecosystem hierarchy: "By killing off all species having predatory tendencies we may have been doing a greater damage to our game species than ever did the predators" (Leopold 1935). Leopold also acknowledged predators in the concept of carrying capacity for prey populations (Leopold 1938b). And it was also a question of values among different groups or individuals: "…The fight over predator control is no mere conflict of interest between field-glass hunters and gun-hunters. It is a fight between those who see utility and beauty in the biota as a whole, and those who see utility and beauty only in pheasants or trout" (Leopold 1939a). Finally, the recreational allure of wolves was worth even more than that of the deer because presence of wolf: "Make the Huron Mountain property more unique and valuable than deer possibly can" (Leopold 1938a).
In the years ahead Leopold had to deal with a wide range of different issues. One issue was connected to rangeland. There was at that time large-scale control of mice, and an extermination (poison) program to eliminate prairie dogs, squirrels and mice. This program had a similar goal to exterminate predators. Leopold wrote about this: ""…No species is inherently a pest, and any species may become one" (Leopold 1943b). In response to the rangeland situation Leopold still used an economic argument: "…too expensive to fit the needs of low-value range lands. It is also too violent, i.e., it frequently kills many other animal species, and its results are often not durable" (Leopold 1943b). Every area that Leopold visited in the early 1940s had a problem with the overpopulation of deer (Leopold 1943a), and he added, why not: "introduce a mountain lion or two". In Kaibab National Forest the deer population still had not re-established itself after 1924. Leopold observed that the overpopulation of deer was a problem for the long-term tree species composition and the regeneration of forest ecosystem (Binkley et al. 2006). In his eyes the forest became too dense and the deer eliminated the groundcover: "The predatory animals, in proper numbers, including wolves, coyotes, foxes, bobcats, hawks, and owls, are necessary to the future forests of Wisconsin. It would be fatal to the forestry program to allow tree-eating rabbits and deer to increase to unreasonable levels" (Leopold 1945a). The deer problem was getting out of control at that time. There was a lack of scientific knowledge about population dynamics and there were many different opinions among forest managers and the public; "The real problem…is not how we shall handle the deer in this emergency. The real problem is one of human management. Wildlife Management is comparatively easy; human management difficult" (Leopold 1945a). It was clear to Leopold that the deer population in Wisconsin had to be reduced drastically. Some saw the thinning of the deer population as a conservation measure (like Leopold), others did not agree. It was considerable explanatory challenges, as today, to tell the public that killing 50 % of the deer population during one hunting season is a conservation policy.
Leopold revisited the Colorado River delta in a canoe 22 years later. What he now saw did not impress him: "I am told the green lagoons now raise cantaloupes. If so, they should not lack flavor…Man always kills the thing he loves, and so we the pioneers have killed our wilderness. Some say we had to. Be that as it may, I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map? (Leopold 1966, 157-158). His nostalgia was not only for the wilderness but also for predators. One of his earliest students, Albert Hochbaum, pointed out that Leopold always wrote about the things he loved. Many of these things, the wilderness, the wolves and the wetlands, are gone. Yet the paradox was that Leopold himself had been a supporter of the changes, Leopold mapped the last wilderness in New Mexico and was a part of the extermination programs in New Mexico and Arizona. Hochbaum inspired him to write essays about wolf and predator control. At this point in time Leopold was still anti-wolf since he believed it was impossible to have wolves where there is livestock: "In thickly settled counties we cannot have wolves, but in parts of the north we can and should" (Leopold 1944b). In 1944, Leopold wrote one of his most famous essays, ‘Thinking like a mountain’ (Leopold 1966, 137). Hochbaums constructive criticisms of Leopold's attitudes to predators had obviously helped Leopold to write the end to this essay. Leopold was also criticized by others for enlightened self-interest in the question of extermination of predators and the hunting regulation of deer populations. Leopold's lifelong dilemma regarding predator control culminated in 1945. Leopold had successfully argued for reducing the deer population by hunting, which caused a lower population than he had expected. He had for so such a long period advocated predation as a controlling factor (i.e. his book ‘Game Management’) that he could not argue that the wolf was necessary to control the deer without painting himself into a corner. He voted for reinstating the bounty on wolves (Leopold 1945a). It is possible to understand this statement in its given context but it is hard to see it in a historical perspective. In the same year Leopold wrote: "The Yellowstone wolves were extirpated in 1916, and the area has been wolfless ever since. Why, in the necessary process of extirpating wolves from the livestock ranges of Wyoming and Montana, were not some of the uninjured animals used to restock Yellowstone? How can it be done now, when the only available stocks are the desert wolf of Arizona, and the subarctic form of the Canadian Rockies?" (Leopold 1945b). Finally in 1945 he wrote that he made wrong decisions in the predator question in Arizona and New Mexico: "I myself have cooperated in the extermination of the wolf from the greater part of two states, because I then believed it was a benefit. I do not purpose to repeat my error" (Leopold 1945b).
During the 1940s the deer problem continued all over the Mid-West. Leopold voted as always as an ecologist, the others for hunting and recreation. Leopold lost the fight and the deer population faced an uncertain future. Everywhere the wolf population was almost extinct. A feeding program for deer was initiated and the forests were threatened by overgrazing. The imbalance took its toll. There were no simple solutions to the predator-prey dilemma. During his lifelong journey both the intellectually and geographically Leopold took his personal philosophy concerning the relationship between man and the land to a higher level which he called ‘The Land Ethic‘ (Leopold 1966, 247).
In his last years Leopold’s attitude toward predators became more clear: "It cannot be right, in the ecological sense, for the deer hunter to maintain his sport by browsing out the forest, or for the bird-hunter to maintain his by decimating the hawks and owls, or for the fisherman to maintain his by decimating the herons, kingfishers, terns, and otters. Such tactics seek to achieve one kind of conservation by destroying another, and thus they subvert the integrity and stability of the community." (Leopold 1947 in Knight & Riedel 2002, 71). In some cases the experience of others echoed in his own life like the description in Leopold (1948).
In the original foreword to the essay collection ‘A Sand County Almanac’, Leopold informs the reader that his book is a kind of "self-portrait": "I do not imply that this philosophy of land was always clear to me. It is rather the end-result of a life-journey, in the course of which I have felt sorrow, anger, puzzlement, or confusion over the inability of conservation to halt the juggernaut of land-abuse. These essays describe particular episodes, ′en route′…" (Leopold 1947 in Knight & Riedel 2002, 319). The essay ‘Thinking like a mountain’ represents the final journey of Leopold’s perception toward predators. Leopold’s intuition was founded in a personal relationship to the mountain, a mountain that recognizes the howl of a wolf: "…deeper meaning, known only to the mountain itself. Only the mountain has lived long enough to listen objectively to the howl of a wolf" (Leopold 1966, 137). Leopold humanised the mountain and gave it feelings. Only the mountain has lived long enough to see longer than people's short-term preferences and feelings for the wolf. But in his younger days Leopold was not thinking like a mountain, but rather as a typically short-sighted human, a manager who thought "no wolves would mean hunters’ paradise". Leopold wrote that there was a big difference between being with or without wolves in the mountain: "...unable to decipher the hidden meaning (they) know nevertheless that it (a deeper meaning) is there, for it is felt in all wolf country, and distinguishes that country from all other land" (Leopold 1966, 137). Leopold had his own experience as a basis for this "My own conviction of this score dates from the day I saw a wolf die" (Leopold 1966, 138), and explained this with "In those days we had never heard of passing up a chance to kill a wolf" (Leopold 1966, 138). When they had shot the wolf and went closer: "We reached the old wolf in time to watch a fierce green fire dying in her eyes. I realized then, and have known ever since, that there was something new to me in those eyes - something known only to her and to the mountain. I was young then, and full of trigger-itch; I thought that because fewer wolves meant more deer, that no wolves mean hunters’ paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view" (Leopold 1966, 138-139). What was wrong with this? Leopold describe several reasons: First the spiritual feelings, a perception of wolfless mountain (Leopold 1966, 139-140). Secondly, ecological reasons: the wolves had an ecological function for the prey population (Leopold 1966, 140). And then the human stewardship had failed to take over the ecological role of wolves: "The cowman who cleans his range of wolves does not realize that he is taking over the wolf's job of trimming the herd to fit the range (Leopold 1966, 140), because: "He has not learned to think like a mountain" (Leopold 1966, 140). The conclusion of the essay "Thinking like a mountain" lifted the question to a higher level, human-nature relationship in the world, and the famous essay ended like this: "We all strive for safety, prosperity, comfort, long life, and dullness. The deer strives with his supple legs, the cowman with trap and poison, the statesman with pen, the most of us with machines, votes, and dollars, but it all comes to the same thing: peace in our time. A measure of success in this is all well enough, and perhaps is a requisite to objective thinking, but too much safety seems to yield only danger in the long run. Perhaps this is behind Thoreau`s dictum: In wildness is the salvation of the world. Perhaps this is the hidden meaning in the howl of the wolf, long known among mountains, but seldom perceived among men." (Leopold 1966, 141). Leopold meant now and ever after that humans must think like mountains (i.e. like nature), and if not we will get instability and loss of diversity. To kill predators is to think like a human, not like a mountain.
Leopold’s words about predators and the predator-prey relationship reflected his position between his scientific and his emotional view of the world. Leopold as a scientist sought tools to dominate nature, to manipulate the system for better utilization. We have seen many examples of this, and his book ‘Game Management’ reflected mostly his utilitarian view of the world. It is easy to see this view in the light of his scientific tradition as a forester, studying relationships in nature between causes and effects, and that no predators (cause) mean more game (effect). However, Leopold tried to build a bridge between science and ethics through perception and intuition, but the ethical dimension became difficult for him, because it opened so many new questions: Can we have wolves where there is livestock? The grizzly is OK, but what about the mountain lion? There are no simple answers to this. Intuition and other forms of perception can only be individual, but Leopold also knew that individuals did not always do what is natural for them. Leopold meant that intuition is possible for everyone, but you need to train it. You can easily see the importance of intuition regarding the predator-prey issue in the essay ‘Thinking like a mountain’, but you can't find simple answers there either (Van Horn 2011). Leopold never meant to come up with simple answers. His relationship to predator-prey questions illustrate that Leopold wanted us to continue in "digging deeper" into the question, in a lifelong process. The views put forward in the essay ‘Thinking like a mountain’ are therefore not characteristic of institutions. Furthermore, his perception is not a pure result of knowledge, aesthetic realization, or instinct alone, but more like a process of social evolution that begins as a synthesis of many modes of perception in individuals and is perpetuated in the community at large because of its survival value. In this sense Leopold’s writing about predators is optimistic for the future. We can see today the progress made by this optimistic view of the future, but still there are extermination programs for large as well as medium-sized and small predators in many regions of the world.
The story of Aldo Leopold’s developing knowledge and attitudes towards predator-prey relationships is interesting because it actualize ancient and contemporary views of the human role in nature in general, and human-wildlife conflicts in particular. Perception as a dimension in Leopold's thinking (e.g. in his attitude to predators), distanced him from many foresters, conservationists and leading ecologists at the same time, as their commitment to a materialist world view seemed total. Even today, lethal control of wild animals perceived as pest species are quite common in developed as well as un-developed environments, and affects terrestrial, marine and freshwater species and ecosystems (i.e. Ahmad 1994; Wickens 1996). Such projects are initiated by private persons, organized communities and governments (Woodroffe et al. 2005a), and still mainly driven by pure utilitarianism. It is difficult to trace a similar temporal tendency to include wider perspectives covering ecological and aesthetic among today’s decision makers compared to Aldo Leopold. This is rather peculiar when considering the advancements in the interdisciplinary field of biology and social sciences (Woodroffe et al. 2005b). Aldo Leopold was a pioneer in this field, and developed his perceptions as a result of a growing body of research-based knowledge during a lifetime. Modern institutions engaged in nature management, on the other hand, are maybe more tied to traditional (i.e. utilitarian) views on nature management because lifetime experiences and perceptions are not processed as in a human mind, and thereby less flexible to adapt to new and broader frontiers of scientific knowledge compared to a pioneering researcher as Leopold.
Harvest traditions are also deeply rooted in nature management, and efforts to increase yields from crops and nature resources have included predator control for centuries (Graham 1973). Governmental agencies traditionally responded to agriculturalists’ demands to develop their nature-based livelihood by fencing, irrigations, cultivation, fertilizer, herbicides, and pesticides in favour of their domesticated species (Treves & Naughton-Treves 2005). By far, the same perceptions pervade modern management actions, and transfer of attitudes to the public (especially hunters) is maintained by extensive courses and seminars focusing on utilitarian perspectives in nature resources.
Modern conservation biology, on the other hand, has received surprisingly little attention among governmental agencies and hunters associations. A common misunderstanding is the clash of interest between harvest and conservation, and it is imperative to link these two perspectives to the sustainability concept. Aldo Leopold succeeded to reach a large majority of readers after his death, through the conservation essays in his book “A Sand County Almanac”.
We want to thank Dan Binkley, Department of Forest, Rangeland, and Watershed Stewardship, Colorado State University, Fort Collins, Colorado, for many interesting discussion about Aldo Leopolds philosophy.
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