Ecology Charles Elton
Daniel Simberloff
  • LAST REVIEWED: 28 May 2013
  • LAST MODIFIED: 28 May 2013
  • DOI: 10.1093/obo/9780199830060-0090


Charles Elton (b. 1900–d. 1991) was a towering figure in ecology in general and animal ecology in particular. Although there were antecedents, he was a chief architect of the concept of the pyramid of numbers and one of the inventors of the concepts of the food chain, food web, and ecological niche. He helped found the field of animal ecology. Inspired by the early American animal ecologist Victor Shelford, Elton in 1927 wrote one of the earliest textbooks on animal ecology and one that long influenced the field. He was a leader in documenting the phenomenon of animal population cycles and seeking their causes. Elton is best known today for a 1958 book on the impact of biological invasions that anticipated the growth of modern invasion biology by twenty-five years. He also contributed to the development of conservation biology through his research and publications on invasion impacts and his insistence on the need for ongoing management of nature reserves based on sound ecological data. Despite a well-known congenital aversion to committee work and public advocacy, Elton was a key player, along with Arthur Tansley, in developing and implementing a British national policy on conservation. A one-time president of the British Ecological Society, Elton was founding editor of their Journal of Animal Ecology, a post he held for nineteen years. Despite these varied and important achievements, largely because of his intensely private and unpretentious nature Elton remains a somewhat enigmatic figure, and no one has undertaken his biography. His many writings are characterized by a remarkable degree of erudition and by a dry, understated wit.


Charles Elton’s life is outlined by Macfadyen 1992 and Southwood and Clarke 1999. He was born in Manchester in 1900. His father was a professor of English literature, and Charles grew up in an academic family. His writings, though biological, have ample and apt references to literature, history, and philosophy. Both of his grandfathers were Protestant ministers, as was his father-in-law, yet Elton showed no interest in religion. Charles was close to his oldest brother, Geoffrey, with whom he shared an interest in nature. Geoffrey’s early death (1927) profoundly saddened Elton, and his Bureau of Animal Population, discussed below, was in some sense a monument to his late brother. After an early childless marriage and divorce, Elton married the poet E. Joy Scovell, and they had two children whom he enjoyed greatly. He read eclectically and was a dedicated pianist. Trained as an army signalman toward the end of World War I, Elton never saw wartime service. He was demobilized in 1919 and accepted at Oxford University, where he studied under Julian Huxley. In 1922 Elton was appointed to a junior demonstratorship, beginning his lifelong Oxford career. In 1921–1924 Elton went on three scientific expeditions to Spitzbergen and in 1930 to Lapland. These trips greatly influenced his conceptions of food chains, the pyramid of numbers, and the trophic-based structure of ecological communities, as well as his interest in population cycles and view of nature as a highly dynamic entity. In 1932 Elton established the Bureau of Animal Population at Oxford, his academic home until his retirement in 1967. Despite his retiring personality, he proved adept at garnering funding for the Bureau and at assembling a small, highly interactive staff. The Bureau focused largely on the population level, with emphasis on population cycles, until World War II, when Elton directed the entire staff in research to aid the war effort by reducing introduced rodent populations and eliminating their toll on agriculture. After the war Elton led the Bureau in research increasingly focused on the level of the ecological community. Despite his efforts to prevent this, the Bureau was closed upon his retirement in 1967. Elton later maintained records for the survey of the biota of Wytham Woods, a long-term Bureau project, and published six papers, including major contributions on invertebrate communities of tropical rain forest. He received several important awards for his ecological research and conservation contributions before his death in 1991.

  • Macfadyen, Amyan. 1992. Obituary: Charles Sutherland Elton. Journal of Animal Ecology 61:499–502.

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    Description of Elton’s scientific approach, development, and ecological contributions and legacy.

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  • Southwood, Sir Richard, and John R. Clarke. 1999. Charles Sutherland Elton. Biographical Memoirs of Fellows of the Royal Society of London 45:129–140.

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    Portrayal of Elton’s life from his earliest years through his retirement and death, with assessment of various influences on his outlook and career. Southwood was perhaps the successor to Elton as the leading British ecologist and an exponent of a modernized, more quantitative version of the approach developed by Elton.

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Bureau of Animal Population—Early Years and World War II

Elton founded the Bureau of Animal Population as he sought generalizations about fluctuations in population sizes of various species and in the wake of his attendance at a 1931 meeting in Labrador bringing together researchers on biological cycles. He had previously used records of the Hudson’s Bay Company to study cycles of furbearers, research that continued in the Bureau for another twenty-five years (Crowcroft 1991, Southwood and Clarke 1999). Elton felt that ecological research was best conducted in small teams of interacting scientists with complementary expertise, and the Bureau reflected this belief. In the 1930s under Elton’s direction, the Bureau did contract research on impacts and management of three introduced species—the muskrat (Warwick 1934 and Warwick 1940) and grey squirrel (Middleton 1935) from North America and the South American nutria (Warwick 1935). During World War II, as a contribution to the war effort, Elton focused all of the Bureau’s resources on finding ways to reduce—and perhaps eradicate—populations of four introduced species in Great Britain that heavily damaged agriculture—the ship rat, the Norway rat, the house mouse, and the European rabbit. Elton’s longtime Bureau colleague, Henry N. Southern, was particularly important in developing methods of controlling mice and rabbits as part of this effort. Although Elton’s optimism that at least the rats could be eradicated proved unwarranted, the research of the Bureau in this area, summarized by Chitty and Southern 1954, was important in rodent control for the next half century.

  • Chitty, Dennis, and H. N. Southern, eds. 1954. Control of rats and mice. Oxford: Oxford Univ. Press.

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    A massive work detailing the research findings of the bureau on rodent control, including a summary chapter by Elton.

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  • Crowcroft, Peter. 1991. Elton’s ecologists: A history of the bureau of animal population. Chicago: Univ. of Chicago Press.

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    The history of the Bureau, including its founding, the evolution of its research, and its personnel and visitors, with the unifying theme of Elton’s dominant role in all facets of its operations. Crowcroft was one of Elton’s later students, and Elton, notoriously unwelcoming to interviewers, granted him time for discussion as well as access to his papers.

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  • Middleton, A. Douglas. 1935. The distribution of the grey squirrel (Sciurus carolinensis) in Great Britain in 1935. Journal of Animal Ecology 4:274–276.

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    Last of Middleton’s series of papers on the gray squirrel invasion. Middleton was a longtime staff member of the Bureau who also studied partridges and other game animals and their parasites. The squirrel studies failed to anticipate the later spread of the gray squirrel and related decline of the native red squirrel.

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  • Southwood, Sir Richard, and John R. Clarke. 1999. Charles Sutherland Elton. Biographical Memoirs of Fellows of the Royal Society of London 45:129–140.

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    Extensive description of Elton’s early interest in population cycles and his founding and staffing of the bureau.

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  • Warwick, Thomas. 1934. The distribution of the muskrat (Fiber zibethicus) in the British Isles. Journal of Animal Ecology 3:250–267.

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    Early Bureau research on the North American muskrat, which contributed to a successful campaign to eradicate the species from Great Britain.

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  • Warwick, Thomas. 1935. Some escapes of coypus (Myopotamus coypu) from nutria farms in Great Britain. Journal of Animal Ecology 4:146–147.

    DOI: 10.2307/1223Save Citation »Export Citation » Share Citation »

    Bureau research on the nutria, recording locations and sources of populations. Much later, a ten-year campaign successfully eradicated the nutria from Great Britain.

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  • Warwick, Thomas. 1940. A contribution to the ecology of the musk-rat (Ondatra zibethica) in the British Isles. Proceedings of the Zoological Society of London A 110:165–201.

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    Final contribution of the Bureau on ecology of the introduced muskrat, with extensive natural history and life history data.

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Bureau of Animal Population—Later Years and Closure

During World War II, Oxford had acquired a large tract of nearby land, Wytham Woods, with the stipulation that it be preserved and used for research. Elton quickly devoted much of his and his students’ and staff members’ energy to studying the animals and habitats of Wytham Woods, including surveys of what species were present in what numbers, how those numbers change through time, and how the different species interact. Kitching 2011 observes that this research at the interface of the community and population levels, heavy on natural history and quantitative data, dominated the Bureau from this period to its closure. A typical doctoral project in the Bureau would involve extremely detailed research on one component of the community (e.g., the fauna of tree holes or decaying wood, the carabid beetles living in marshes and near water, or the factors controlling population sizes of terrestrial isopods). Crowcroft 1991 and Simberloff 2012 describe how Elton envisioned the ultimate goal of the surveys and fine-scale research as a complete understanding of the operation of one ecosystem—Wytham Woods—as a model ecological system. Throughout its operation, the Bureau was home to many students who became leading ecologists as well as to numerous short- or long-term visitors who wished to use the data stored at the Bureau and to interact with Elton and staff members. J. W. S. Pringle, named as Linacre Professor of Zoology at Oxford in 1961, closed the Bureau in 1967 upon Elton’s retirement (over Elton’s strenuous objections), because Pringle wanted a much bigger building for a larger and more integrated Department of Zoology (Crowcroft 1991, Southwood and Clarke 1999).

Early Books and the Evolution of Animal Ecology

In 1927 the young Elton (see Elton 2001) wrote an animal ecology textbook that became a classic. Inspired by field trips to Spitzbergen and by the first animal ecology monograph (Shelford 1913), Elton depicted a dynamic nature structured by interactions. Although short, Elton’s Animal Ecology covers many subjects that became prominent parts of modern ecology (Leibold and Wootton 2001). As Hardy 1968 observes, Elton used detailed natural histories of species to unravel how nature operates, famously defining ecology as “scientific natural history.” Elton’s book is short on mathematical theory and experiments, which are prominent parts of modern ecology. He advanced theories, but these were rarely quantified and were never expressed as abstract equations or falsifiable hypotheses. Absence of discussion of experiments was likely because few if any ecological experiments had yet been performed. Elton often cited biological invasions as uncontrolled experiments showing how one species affects others. Thus he focused on characteristics of food chains. Elton’s conception of the ecological niche was primarily trophic—where a species fits in the web of interactions (McIntosh 1985)—though he recognized environmental constraints on where a species could exist. His emphasis on a “niche” defined by species’ interactions influenced subsequent research on this ecological phenomenon. A key question for Elton was what controls population sizes of different species, and he sought the answer by examining variation of population sizes in time and space. Throughout this book, Elton emphasized the importance of accurate survey and census data in order to answer questions at the population and community levels of ecological organization. This concern is reflected in the assiduous collection of such data throughout the existence of the Bureau of Animal Population. Soon after publishing his textbook, Elton published three short books for lay readers. The Ecology of Animals (Elton 1933a) is an abridgment of Animal Ecology. Animal Ecology and Evolution (Elton 1930) treats the role of evolution in ecology. Elton was intrigued by evolution, a new concept at the time, but he did not accord it a substantial role in short-term dynamics of ecological communities: a notion that subsequently became more widely accepted, particularly as a driver of host-pathogen dynamics. Exploring the Animal World (Elton 1933b) explained the methods and importance of studying natural history for ecological understanding, depicting natural history as a more rigorous, quantitative version of pastimes the British had long practiced, such as bird watching.

Later Contributions to Animal Ecology

Remarkably, for the next thirty years, Elton published very few major papers on animal ecology (although two books, Voles, Mice, and Lemmings: Problems in Population Dynamics [Elton 1942, cited under Contributions to Understanding Population Cycles] and The Ecology of Invasions by Animals and Plants [Elton 1958, cited under the Invasions Monograph and Its Influence], were major ecological contributions). Rather, he produced occasional short papers, often opinion pieces; some had summaries of field data, especially from Wytham Woods. He also wrote many book reviews on ecological subjects. The one exception was an important paper with his former student, Richard S. Miller (Elton and Miller 1954) rationalizing the progressive shift in Elton’s and the Bureau’s research focus from the population to the community level. Pointing to the increasing evidence of the role of interspecific interactions in governing population size, they assert that studying population dynamics forces one to study the species coexisting with the target population—in short, the community. This paper also reiterated the highly dynamic nature of animal populations and communities. In addition, many of Elton’s students published extensively on their research at Wytham Woods and elsewhere, and much of this research was important in the development of ecological thinking in several directions (Cox 1979). Although these papers rarely listed Elton as coauthor, his influence was evident and usually acknowledged. Sadly, one of his most substantial conceptual papers during this period, “Competition and the Structure of Ecological Communities” (Elton 1946), is seriously flawed because of Elton’s statistical naiveté and the absence of a null hypothesis (Simberloff 1970). Elton 1966The Pattern of Animal Communities—is the book that he viewed as the culmination of his research life and intended as a guide to how to conduct ecological research. Ironically, it has had little influence on the field compared to his short early textbook. Kingsland 1985 notes that by the 1960s ecology had largely moved on, dominated by quantitative theoretical frameworks, statistical tests, experiments, and the advent of ecosystem ecology with its emphasis on energy flow and materials cycling. These were all subjects quite distant from Elton’s expertise and interest. Pattern is rather an attempt to gather all the information—mostly in the realm of natural history—from the years of research at Wytham Woods to produce a picture of the workings of one system as a model for how nature is organized. Though based on massive data, it consisted of largely verbal descriptions and models, and this inductive approach had by then fallen from favor. After Pattern, well into his retirement, Elton traveled to the tropics and studied forest invertebrate communities there, producing an important paper with new insights into their structure and interactions (Elton 1973). Often in his ecological writings, Elton was at pains to show how scientific ecology can aid the solution of practical problems in managing natural resources. It is thus not surprising that Elton’s last publication was a short paper advancing conservation ideas based on his research on tropical forest invertebrate communities (Elton 1975).

British Ecological Society

Members of the British Vegetation Committee founded the British Ecological Society in 1913, led by the charismatic botanist and pioneering ecologist, Sir Arthur G. Tansley, who developed the ecosystem concept (Ayres 2012). Early British Ecological Society research activities were almost exclusively on plants and the description of vegetation. Its first journal, the Journal of Ecology, was heavily focused on plants, and much research of the society’s scientists was on plant succession. Geologists also contributed to the early development of the society and ecological knowledge base, through research on the physical nature of the substrate and paleobiological data showing the dynamism of vegetation. However, Sheail 1987 observes that animals and their interactions with plants were nearly absent. By the early 1930s, in the wake of Elton’s animal ecology book and increasing knowledge of American animal ecologists such as Shelford, the Society recognized the importance of broadening its scope. Elton led the way in moving to redress the imbalance of the Society by demanding that they demonstrate its commitment to support all areas of ecology. He suggested a separate journal for animal ecology, with the Journal of Ecology to focus wholly on plants. In 1931 the Society accepted a recommendation from Elton and Tansley for a new journal, and Elton raised enough money to protect the Society against any deficit that might arise from expenses of the new publication. The first issue of the Journal of Animal Ecology appeared in 1932, with Elton as editor-in-chief, a position he held for nineteen years, initially assisted by his colleague in the Bureau, Dennis Chitty. In addition to publishing nine of his own research papers in the Journal of Animal Ecology, Elton encouraged publication of research in several areas of great interest to him, particularly population cycles, introduced species, and conservation, as well as detailed natural history studies. Kingsland 1985 points out that, surprisingly—given his lack of expertise and apparent interest in mathematics and statistics—Elton’s tenure as editor-in-chief produced an increasing flow of papers on quantitative methods, especially at the population level. Elton also used his editorial post to write at least sixty-two book reviews in the journal. Many of them, particularly of books on subjects of special interest to him (such as animal ecology, biogeography, population cycles, biological invasions, and conservation) were more than simple assessments of the volume at hand. Rather, they digressed into broader discussions and served as a platform for Elton to write expansively about various ecological issues.

Contributions to Understanding Population Cycles

As an undergraduate, Elton had been fascinated by accounts of dramatic vicissitudes in some animal populations. Experiencing a lemming migration during the Lapland expedition in 1930 heightened this interest, and Elton devoted much of his early career to studying population crashes, explosions, and cycles. By the time of the Matamek (Labrador) Conference on Biological Cycles in 1931, Elton was a recognized authority, and he contributed many data and ideas at the conference (Elton 1933; Meine 1988; Newton 2006). He met Aldo Leopold and other prominent workers on animal cycles there, and he also made the contact that funded the opening and first two years of the Bureau of Animal Population (Crowcroft 1991). Elton primarily studied cycles through two data sets, one assembled through annual fur returns of the Hudson’s Bay Company (particularly the lynx and its main prey, the snowshoe hare, both of which cycle remarkably regularly), and the other consisting of data gathered by a team, including Elton, on the voles and field mice of Bagley Wood, near Oxford. Many of Elton’s publications on cycles were coauthored with Dennis Chitty, whom he recruited early to the Bureau and who subsequently became the leading authority on the subject, moving from the Bureau to the University of British Columbia after twenty-six years (Chitty 1966). Cycles are the subject of nineteen of Elton’s published papers, plus a book that is one of the classics in the field, Voles, Mice and Lemmings: Problems in Population Dynamics (Elton 1942). In addition, Elton’s interest in epizootic diseases, spurred by the possibility that they could contribute to cycling, led to several papers. Elton’s earliest tentative hypothesis for cycles of the Canadian furbearers was that they were related somehow to sunspot cycles, an idea he rejected after several more years of study (Elton 1935). He came to believe that the lynx and hare cycles were endogenously produced by the lynx preying on the hare until the latter became scarce enough to cause a food shortage for the former, after which the lynx population would crash, and the hare population would recover. However, he thought that the cycle was synchronized over large regions by some unknown climatic factor (Elton and Nicholson 1942). The research on rodents led to a general theory, summarized in its most comprehensive form by Chitty, that many species usually regulate their own densities through various hormonal changes without predators and climate playing roles.

Early Contributions to Invasion Biology

Elton’s interest in invasions was triggered in his earliest days as a biologist, and his early animal ecology book (Elton 1927) cited many invasion impacts. In 1933 he published a featured newspaper letter advocating a census in Great Britain, explaining its importance in tracking the harmful impacts of the muskrat and other invaders (Elton 1933a). A popular book the same year (Elton 1933b) based on BBC radio broadcasts included a chapter, “Plagues of Animals,” about harmful impacts of introduced animals and plants. Elton also used his position as founding editor of the Journal of Animal Ecology to review books on invasions, often expanding his reviews well beyond the book at hand to include general comments on the importance and pervasiveness of invasions. For instance, a review of a monograph on the Chinese mitten crab in Europe turns into a diatribe about the “growing band of invaders” in Britain, including the North American muskrat, grey squirrel, rainbow trout, and Colorado potato beetle (Elton 1936). A review of a book on the eradication of the malaria mosquito Anopheles gambiae in Brazil included a digression on the “major engagements in a violent struggle against the spread of undesirable plants and animals that is affecting every country” and a discussion of mammal eradications in Great Britain and campaigns against insects and viruses in the United States (Elton 1944). Elton directed the Bureau of Animal Population during the 1930s in research on three invasive species in Great Britain—the muskrat, the grey squirrel, and the nutria. During World War II, as a contribution to the war effort, Elton turned the Bureau wholly toward research on four introduced agricultural pests in Great Britain: the Norway rat, the ship rat, the house mouse, and the European rabbit. During the war, Elton also published a remarkably wide-ranging short article on invasions in a Polish émigré journal as a break from “working almost entirely upon practical and immediate problems connected with war needs” (Elton 1943). This article pointed to the ecological and biogeographic consequences of the ongoing global rearrangement of species caused by human activities, repeated many examples of invasion impacts from his earlier writings. It foreshadowed what was to become Elton’s most famous work fifteen years later.

Invasions Monograph and Its Influence

Elton is best known for his remarkable short book on how biological invasions affect native animals and plants (Elton 1958), based on three BBC radio broadcasts in 1957. This work is often cited as having founded the field of invasion biology: MacIsaac and Ricciardi 2008; Richardson and Pyšek 2008; and Davis, et al. 2001 argue that in so doing, it led the field in an unproductive direction by viewing introduced species as categorically different from native ones. In fact, the immediate influence of Elton’s monograph was slight (Simberloff 2011). It was written for a lay audience, and many scientists read it as well, but it did not trigger a rapid increase in research on invasions. Rather, as more and more impacts of various invasions were noted in subsequent years, interest in the phenomenon rose and was crystallized by a multi-year, international project on biological invasions in the 1980s mounted by the Scientific Committee on Problems of the Environment that engaged dozens of ecologists in a consideration of what caused some invasions to be have huge impacts and what could be done to manage invasions (Simberloff 2011, Simberloff and Rejmánek 2011). Many scientists participating in the project recalled having read Elton’s monograph years previously, and some cited it. As the field of invasion biology rapidly expanded, in 2000 the University of Chicago Press reprinted the monograph, which found a receptive audience among scientists, students, and lay readers. By this time, the field was well established, so Elton could not have misled it at its outset (Simberloff 2011). Elton 1958 adumbrated almost all aspects of invasions that became prominent subjects of research once the field of invasion biology arose, except for evolution of invaders and of native species in response to invasion of new sites (Simberloff 2000). Chew 2006 notes abundant earlier research on introduced species. However, Elton’s was by far the most widely ranging discussion, especially his catalogue of impacts of over one hundred introduced species of animals, plants, and microbes in all habitats; this was the major early work signaling biological invasions as a key threat to conservation.

Contributions to Conservation

Although Elton is recognized for his role in developing ecology and invasion biology, his conservation contributions are less well known, largely because of his aversion to committee work and his intensely private nature (Simberloff 2012a). Elton was concerned with conservation from his earliest academic days, and he related many of his scientific findings to conservation applications. His key insight was that the dynamic nature of populations means one cannot simply put aside a nature reserve and expect it to persist (Elton 1933 and Elton 1938). Rather, ongoing changes will necessitate management, and effective management requires ecological research on the populations in the reserve. Foremost among changes in Elton’s view were biological invasions, but population explosions, crashes, and cycles were also much on his mind. He concluded by the 1930s that nature conservation in general and reserves in particular needed government status for long-term success. His input into conservation in Great Britain took a major turn with his memorandum in 1942 to Sir Arthur Tansley, who chaired a British Ecological Society committee on “Nature Conservation and Nature Reserves.” Elton’s recommendations dominate the committee report (Committee of the British Ecological Society 1944), summarized and explained in a popular book (Tansley 1945). Responding to the report in 1949, the British government established the Nature Conservancy to select and manage preserves and give advice on conservation. Despite his aversion to such chores, Elton served as charter member of the Conservancy, and Sheail 1989 credits him with adding a research branch to the Conservancy and establishing surveys as a key tool for reserve management. Elton is best known to conservationists for the final chapters of his invasions monograph (Elton 1958, cited under the Invasions Monograph and Its Influence). These are devoted to conservation, particularly in light of the damaging invasion impacts that Elton depicted in the book, and they include a hypothesis that has become a touchstone of much modern conservation: biological diversity begets stability. This hypothesis is often credited to Elton but was probably first posed less formally by his friend, the American conservationist and biologist Aldo Leopold (Simberloff 2012b). Elton had long friendships with Leopold as well as with Tansley (Ayres 2012) and the British conservationist Sir Frank Fraser Darling. All three men were influential, visible, and active in conservation policy decisions. Because of their public personas, they are well-known figures in the history of conservation. For all three, the interaction with Elton enriched their insights and made them more effective advocates.

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