George Richard (Dick) Potts (1939–2017)

Abstract

The Grey Partridge Perdix perdix occupied a special place in Dick Potts’ heart. His intuitive feel for the species was uncanny, and his boundless enthusiasm for it infectious. On the annual ritual of the partridge counts in Sussex, those colleagues lucky enough to have shared a Landrover with him recall the countless times when, within a huge featureless stubble field, he knew exactly where the single partridge covey was hiding and detected it long before they did. Counting with Dick was a switchback experience, alternating between elation at finding Grey Partridges, despair at the ever-widening areas devoid of them, and intense discussions about research and management needed to reverse their decline. Thus are legends made, research teams brought together and students started on their conservation careers. Dick was born on 6 December 1939 to a farming family in Tunstall, North Yorkshire. He showed a keen interest in wildlife from an early age, encouraged by his father Edward and his schoolteacher Mr Hardisty. An enduring memory was of the harsh snowy winter of February 1947 that killed the resident Barn Owls Tyto alba and many other birds, while Grey Partridges foraged desperately in the stackyard. Taking part in ploughing and harrowing were always opportunities for him to watch birds and learn more about agriculture from the farm hands. A first realization of how toxic farm chemicals could be arose from a conversation with a tractor driver drinking milk in an attempt to counteract the effects of the herbicide Denocate. Dick's secondary education was at Scorton Grammar School, finishing in 1958 when he became its first pupil to enter university. He studied zoology at Durham University, specializing in ecology and entomology, as well as participating in two expeditions to the Faeroes to investigate the numbers, distribution and biology of the Great Skua Stercorarius skua. After graduation, he undertook a PhD on the European Shag Phalacrocorax aristotelis, studying the effects of age, nest density and nest-site quality on breeding success on the Farne Islands, Northumberland. He also collaborated with Shell Research to investigate the accumulation of organochlorine insecticide residues in the marine food chain and its consequences for Shag reproduction. Particularly traumatic was the loss of 82% of his study species within just a few days at the end of May 1968, when he witnessed at first hand the devastating impact on seabirds of paralytic shellfish poisoning caused by blooms of the dinoflagellate Alexandrium tamarense. This reinforced his interest in environmental poisons and led to a lifelong fascination with the processes that regulate bird abundance. In the same year, he was head-hunted by John Ash, whose early seabird-ringing efforts on the Farne Islands had preceded Dick's own, and who had undertaken pioneering work on Grey Partridges and agrichemical use with the ICI Game Research Station and its successor the Game Research Association (shortly to become the Game Conservancy Trust). Dick's new job was to run the Partridge Survival Project, which sought to establish why the Grey Partridge was in decline. His study area was a vast 62-km2 area of the South Downs in West Sussex, encompassing 12 farms with different farming styles and keepering regimes. Dick was in his element – his farming background and ecological insight led him to realize that to understand changes in partridge abundance, he needed to understand changes in the partridge environment. Hence he not only initiated the annual gamebird counts to measure Grey Partridge abundance and breeding success, but a much wider survey of cropping, pesticide use, arable weeds and invertebrate abundance that developed into the Sussex Study, one of the longest-running studies of the arable ecosystem in the world, now in its 50th year. Comparing Grey Partridge vital rates, changes in abundance and changes in food availability on different farms led him to identify three main causes of partridge decline: reduced chick survival through herbicide-induced reduction in chick-food invertebrates, lack of suitable nesting habitat reducing settling density, and poor nesting success due to predation. He dubbed these three factors the ‘three-legged stool’ on the grounds that, if any leg failed, the partridge stool would collapse. His farmland work was ground-breaking because previous conservation thinking had concentrated on pristine natural habitats, not heavily managed man-made ones. His was the first piece of research to reveal convincingly that agricultural pesticides could affect a farmland bird indirectly by undermining its food chain. It was popularized through The Partridge Puzzle, a documentary starring Dick and produced by the Royal Society for the Protection of Birds (RSPB) in 1976, earning a joint silver medal for scientific films at the Montreux Festival. Dick became the Game Conservancy Trust's Director of Research in 1977. Ever mindful of the ongoing decline of the Grey Partridge, he sought to verify the Sussex conclusions through farm-scale experiments and develop practical solutions compatible with modern farming. The Cereal and Gamebirds Research Project (1983–1990) employed entomologists, agronomists and botanists to invent and fine-tune ‘Conservation Headlands’, the strip of cereal crop closest to the field margin that is selectively sprayed to allow an understorey of insect-rich weeds to grow and provide chick food, and ‘Beetle Banks’, tussocky grass strips that break up large fields and provide refugia for beetles and nesting areas for birds. Although originally developed with Grey Partridge conservation in mind, such forms of management were found to have much wider biodiversity benefits (e.g. for rare arable flora, butterflies, pollinators and natural enemies of crop pests). His Salisbury Plain Experiment (1984–1990) demonstrated conclusively that generalist predators affected partridge breeding abundance as well as breeding success, in contradiction to accepted ecological wisdom. Dick also turned his skills to the conservation of other species including Brown Hare Lepus europaeus, Red Grouse Lagopus lagopus scotica and Eurasian Woodcock Scolopax rusticola. As Director-General of the Game Conservancy Trust from 1993 until his retirement in 2001, Dick saw shooting as a potential win–win for shooters and conservationists, on the basis that appropriate game management could produce more game to shoot as well as many associated wildlife benefits; this was the notion of ‘Conservation through Wise Use’. Although it could produce oases of wildlife in a farmed landscape, it became clear that wider outreach to the farming community was necessary to reverse the fortunes of the Grey Partridge and other declining wildlife. He seized the opportunity offered to him in 1992 by the executors of the late Lord and Lady Allerton to turn Loddington Farm, Leicestershire, into a demonstration farm that embraced the Trust's management precepts, measured the wildlife gains and evaluated the costs relative to farm profitability. Its combination of profitable environmentally friendly farming, applied research into wildlife, soil and water management, and community engagement have given it a Europe-wide profile. The mix of applied farmland research and tangible evidence of conservation success that Dick fostered helped shape set-aside rules and agri-environment schemes in the UK for the benefit of farmland wildlife. Controversy was not a deterrent to Dick, who believed that scientific evidence was vital in wildlife conflict resolution. He initiated the Joint Raptor Project (1992–1996), which quantified the impact of Hen Harriers Circus cyaneus and Peregrines Falco peregrinus on Red Grouse at Langholm Moor, Scotland. The project demonstrated that, at high Hen Harrier densities, August Red Grouse density was 50% lower than in the absence of Hen Harriers. Consequent on this impact, driven shooting was no longer possible, so moorland management for Red Grouse ceased, leading to breeding wader numbers halving, fox and crow abundance doubling, and Hen Harrier numbers falling from a peak of 20 breeding females to two. In other words, shooting and conservation were both losers. Dick's pragmatic solution, proposed in 1998, was a quota scheme that limited breeding harriers to a pair per 25 km2 of grouse moor. It is still the subject of intense debate today. Dick remained passionate about Grey Partridges throughout his life, and retirement was an excuse to spend more time on them. He wrote two partridge monographs, The Partridge: Pesticide, Predation and Conservation in 1986 that became Wildlife Society Book of the Year, and Partridges: Countryside Barometer in 2012 within the Collins New Naturalist series. In 2003, under his guidance, the Arundel Estate implemented the full partridge management package on the western side of his beloved Sussex study area, where the Grey Partridge had come close to extinction. Within eight years, numbers had increased from three pairs to 200 pairs on 1000 ha, turning the Estate into a wildlife haven and restoring a wild Grey Partridge shoot – wonderful testimony to the effectiveness of his life's work. Dick received a DSc from the University of Durham, the Massey-Ferguson National Award for Services to Agriculture, the Wildlife Society Group Achievement Award, the Godmin-Salvin medal of the British Ornithologists’ Union, the IUGB Award for 35 years’ Service to Gamebird Research and Management, the Country Landowners Association Contribution to Countryside Award, a Fellowship of the Royal Agricultural Society, a Leverhulme Emeritus Fellowship, an Honorary Doctorate at the University of Sopron in Hungary and, posthumously, the RSPB medal for an outstanding contribution to nature conservation. He sat on the Council of the British Trust for Ornithology and served as Vice-President of the British Ornithologists’ Union, Vice-President and then Chairman of the World Pheasant Association, Chairman of the Cranborne Chase Area of Outstanding Natural Beauty, Chairman of the Small Game Commission and President of the Applied Science Division of the International Council for Game and Wildlife Conservation. He also sat on committees of English Nature, the Natural Environment Research Council, the Department for Environment, Food and Rural Affairs, the British Trust for Ornithology, the Wildfowl & Wetlands Trust and on the Advisory Board of The Edward Grey Institute of Field Ornithology at the University of Oxford. Fit and energetic his whole life, he died on 30 March 2017 after the sudden onset of pancreatic cancer. His drive, enthusiasm and vision will be sorely missed.