Graeme James Caughley

Graeme James Caughley (28 September 1937 – 16 February 1994) was a New Zealand population ecologist, conservation biologist, and researcher. He combined empirical research with mathematical models, and supported the declining population paradigm.

Childhood Caughley was the middle of three children and the only son born to John Norman Caughley and Thelma Caughley. His father would take him on excursions, while his mother encouraged his curiosity. As a young child Caughley was very inquisitive and he recalled finding a seashell on top of a hill. At the age of seven, he determined that the sea must have once covered the hill and was proud to have resolved the problem. This event encouraged him to learn more about New Zealand's geology and as Gunn and Walker explain "Ecology had a close call with Graeme Caughley. He almost chose geology at the start of his career..."

Education Bachelors Caughley attended Victoria University College in Wellington, New Zealand from 1956 to 1959. Tyndale-Biscoe writes that "there is no record of any particular lecturers influencing his thinking." In his last two years Caughley dropped down to part-time and went to work with his friend Thane Riney at the New Zealand Forest Service on feral goat herds.

Masters Caughley continued his education at the University of Sydney (1960–1963) with his advisors Charles Birch (insect population ecologist) and Harry Frith (ornithologist). Frith was chief of the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) and Caughley used the CSIRO sheep station to study the ecology of kangaroos. which was in contrast to what he had seen in red deer. He interpreted this to mean that random grouping was density dependent with increased grouping at higher densities. An approximation of density could then be found by taking the average number of individuals per group in a given area. Continuing his research he found that red kangaroos are much more drought-tolerant than grey kangaroos, which visit water three times more often. towards his doctoral work. He decided to work on tahr because at that time everyone claimed to be an expert on red deer and he thought that he would make a greater contribution working on the lesser known tahr.

Significant contributions During 1966, Caughley presented methods by which to determine mortality patterns in mammals. He looked at mortality rate curves (qx) among ungulates, rats, voles, sheep, and man he found that they followed a common pattern. This "u" shaped pattern had a high juvenile mortality followed by a decrease and then a steady increase in mortality punctuated by a sharp increase with maturity. With this mortality pattern it was shown that although age of mortality differs among species as well as cause of death (disease, lack of food, predation) the trend that mammal species follow is similar. He wrote that most of the animal world had a season for breeding and that if births were treated as occurring at only one point in time then these equations could be used for seasonally breeding populations. they claim that the questions asked by entomologists are not necessarily those asked by mammalogists and vice versa. R. S. Millar stated in his review that until this book literature on analyses had been scattered and difficult to understand, but Caughley made topics more readable.

Caughley also co-published a book on Wildlife Ecology, Conservation, and Management: the first portion of the book covers an overview of population ecology while the second part is on applied ecology or management. His last publication Conservation Biology in Theory and Practice gives a history of prehistoric and historic extinctions as well as a collection of case studies. It contains chapters that look at the different ways population dynamics, risks, and legislation are approached. Perez claims that there is such a high volume of conservation textbooks today, but this one is more of a handbook on diagnosing and treating problems with populations. This diagnostic style is in part due to it being written by two field biologists, something that Clinchy and Krebs say took sixteen years in the making. That this is the first time that field biologists have written a book on conservation biology is a breakthrough in conservation biology. This paradigm seeks to discover why a population is declining and how to prevent further declines. This opposes the small population paradigm that seeks to determine how long a small population will last. At a first reading it is difficult to discern what the counter argument is since they state that they agree with Caughley in that a broader understanding and synthesis of ideas is required.

To truly understand the controversy one must read the two articles of "Viva Caughley!". Both articles were written as a rebuttal to Hedrick and colleagues, who claim that Caughley's ideas are overly simplistic. Clinchy and Krebs explain that in fact it was not simple enough and "the basic distinction in conservation biology is between field biologists and lab scientists". It then was a heated debate against those that used expensive modelling programs and those that went out to do the same thing with inexpensive tools purchased at a hardware store such as "pvc pipe and bits of string". Young and Harcourt suggest that upon careful observation there is little disagreement between what Caughley said and the rebuttal that Hedrick and colleagues gave, although they do castigate Hedrick and other PVA advocates for emphasising predictions based on models over more justifiable sensitivity analysis and real world threats to populations.

Honours and awards As listed by Tyndale-Biscoe

1960 Caughley Beach at Cape Bird, Ross Island named after Caughley in recognition of his work on Emperor and Adelie penguins

1970 Queen Elizabeth II Post-Doctoral Fellowship

1978 Analysis of Vertebrate Populations awarded 'Book of the Year' by the Wildlife Society, Washington, D.C.

1987 Kangaroos: Their Ecology and Management in the Sheep Rangelands of Australia awarded Whitley Book Award Certificate of Commendation by the Royal Zoological Society of New South Wales

1992 Elected to Fellowship of the Australian Academy of Science

1993 Awarded CSIRO Chairman's Medal for outstanding research achievements and leadership in the field of vertebrate ecology

1994 Peter Scott Award for Conservation Merit, Species Survival Commission of the International Union for the Conservation of Nature

Selected works Gunn, Anne, and Graeme Caughley. Conservation biology in theory and practice. Blackwell Science, 1995. Caughley, Graeme. The deer wars: the story of deer in New Zealand. Heinemann, 1983. Caughley, Graeme, James M. Peek, and Susan L. Flader. "Comments on" Natural Regulation of Ungulates (What Constitutes a Real Wilderness?)"." Wildlife Society Bulletin (1973–2006) 9, no. 3 (1981): 232–238. Caughley, Graeme, B. Brown, and J. Noble. "Movement of Kangaroos After a Fire in Mallee Woodland." Wildlife Research 12, no. 3 (1985): 349–353. Barker, R. D., and Graeme Caughley. "Distribution and abundance of kangaroos (Marsupialia: Macropodidae) at the time of European contact: South Australia." Australian Mammalogy 17 (1994): 73–83.

Footnotes