On March 29, 1900, English zoologist and animal ecologist Charles Sutherland Elton was born. Elton‘s name is associated with the establishment of modern population and community ecology, including studies of invasive organisms. In 1927, Elton published his now classic book Animal Ecology, in which he took up the concept of food chains that had been originally introduced by the African-Arab scientist and philosopher Al-Jahiz in the 9th century.
“Food is the burning question in animal society, and the whole structure and activities of the community are dependent upon questions of food-supply.”
— Charles Elton (1960)
Charles Elton – Youth and Education
Charles Elton was born in Manchester as son of the literary scholar Oliver Elton and children’s writer Letitia Maynard Elton (née MacColl). In 1901 the family moved to Liverpool where Oliver Elton had been appointed professor. Elton attended Liverpool College and Oxford University and graduated in zoology in 1922. It was during his studies at Oxford that he conceptualized his ideas about animal ecology. He intended to turn natural history into the science of ecology by applying the scientific method to study the lives of animals in their natural habitats and their interactions with the environment. Elton’s entire scientific career took place at Oxford University. In 1923, he was hired as a demonstrator. In 1932, two years after his fourth Arctic expedition, which had taken him to Lapland, he founded the Bureau of Animal Population, which became a center for the collection of data on fluctuations in animal populations, and the Journal of Animal Ecology. In 1936 he became a reader in Animal Ecology.
Spitsbergen and the Arctic
Elton was appointed assistant to Julian Huxley during his studies and accompanied him on an expedition to Spitsbergen. There, they made an ecological survey of Arctic vertebrates. The project later continued on three subsequent Arctic expeditions in the years 1923, 1924, and 1930. Due to Elton’s experience with the Arctic, the Hudson Bay Company consulted him and he began studying fluctuations in the populations of animal species of interest to the fur trade. These studies were later followed by similar research on British mouse and vole populations.
Overpopulation and Ecosystem
To one of Charles Elton’s greatest influencers belonged Alexander Carr-Saunders, who published ‘The Population Problem: A Study of Human Evolution‘ in 1922. The work outlines the effect of human overpopulation on flora and fauna on Earth. The work’s ideas were later applied on animals by Charles Elton. Charles Elton was among the first to study the relationship between animals and plants in their natural environment and to define animal behaviour as a result of the living environment. He introduced the concept of the food chain and was one of the early environmentalists and invasion biologists as he was deeply involved in the impact of introduced species on a habitat. Together with the US American Aldo Leopold, he coined the term ecosystems. He introduced the term ecological niche. The ecologist Joseph Grinnell had described the concept earlier, but Elton’s work was independent of it.
World War II
In 1936, he was appointed reader in animal ecology at the Oxford University. Further, the Corpus Christi College elected him a senior research fellow. During the time of World War II, the Bureau of Animal Population was given the task to find efficient methods for the control of rats, mice and rabbits by the Agricultural Research Council. Elton later began a 20-year survey of animals and their interrelationships on Oxford University’s Wytham estate. He also continued his studies in tropical America after his retirement.
“The discoveries of Darwin, himself a magnificent field naturalist, had the remarkable effect of sending the whole zoological world flocking indoors, where they remained hard at work for fifty years or more, and whence they are now beginning to put forth cautious heads into the open air.”
— Charles Elton (1960)
To Charles Elton’s biggest achievements belongs his book ‘Animal Ecology‘, published in 1927. In it, Elton describes the principles of ecological studies of animal behaviour and life history, such as food chains, the size of food items, the ecological niche and the concept of a pyramid of numbers as a method of representing the structure of an ecosystem in terms of feeding relationships. After the Second World War, Elton became much more concerned with the impact of invasive species on natural ecosystems.
The Ecology of Invasions by Animals and Plants
His 1958 book The Ecology of Invasions by Animals and Plants  founded invasion ecology as a separate sub-discipline. The first part of the book focuses on the invader species and their mode of transport into the new environment. The second part of the book focuses on the struggle between invasive species and the indigenous, though some invaders enter habitats with no prior species filling their specific niche. The final part of The Ecology of Invasions by Animals and Plants deals with the issue of conservation and its importance to maintain species diversity. The research projects include a 20-year study of the interaction of individual animal species in wetlands, water bodies and woody plants in an area near Oxford. He is also the originator of Elton’s number pyramid, which deals with the question of why the number of predators is decreasing across the food chain.
Elton was elected a Fellow of the Royal Society in 1953, which awarded him the Darwin Medal in 1970. In 1967 he was awarded the Linné Medal of the Linnean Society of London. In 1968 he was appointed an honorary member of the American Academy of Arts and Sciences.
Charles Sutherland Elton died on May 1, 1991, at age 91.
References and Further Reading:
-  Short Biography of Charles Elton
-  A History of the Bureau of Animal Population
-  John Mole: Obituary: E. J. Scovell, In: Independent, 12. November 1999
-  Charles S. Elton, Animal Ecology, New York, The Macmillan Company, 1927
-  Charles S. Eltonm 1958: The ecology of invasions by animals and plants. London: Methuen, Progress in Physical Geography 31(6):659-666, DOI: 0.1177/0309133307087089, via Research Gate
-  Evans, P. (1966). Voles, Mice and Lemmings, by Charles Elton. Weinheim: Cramer. Wheldon & Wesley, Codicote, Hitchin, Herts. £7 10s. Oryx, 8(4), 255-255. doi:10.1017/S0030605300004932
-  Elton, Charles (1938). “Notes on the Ecological and Natural History of Pabbay, and Other Islands in the Sound of Harris, Outer Hebrides”. Journal of Ecology. 26 (2): 275–297.
-  C. S. Elton, The Ecology of Invasions by Animals and Plants, London: Methuen and Co. Ltd, 1958.
-  Charles S. Elton at Wikidata
-  Timeline of British Ecologists, via DBpedia and Wikidata