Until World War I grey partridge numbers in Europe alone were at least 75 million, but this number has now quite dramatically fallen to less than 3 million. The grey partridge has overcome the effects of several ice ages and thrived in World Wars but it is now expected to disappear completely from huge areas of farmland. Globally, there are at least 45 species of game bird that have the word partridge in their name, but in Partridges: Countryside Barometer G. R. Potts devotes himself to the grey, red-legged and chukar partridges, with particular emphasis on the grey partridge due to its well-known decline in Britain.
In this groundbreaking addition to the New Naturalist series, Potts explores how mankind and partridges have evolved together, both ultimately dependent on grasslands rather than forests. For thousands of years, both ate grass seeds and this continued until cereals largely replaced them. Hundreds of species of plant and insect that partridges and other birds eat thrived on farms for thousands of years until the dawn of the pesticides era. Since then the long decline in partridge abundance has been a barometer for biodiversity over vast swathes of the Northern Hemisphere.
Highlighting the positive example of the Norfolk Estate in the Sussex Study area, Potts investigates how both grey and red-legged partridge numbers have been increased, flourishing in a highly productive and profitable system of farming and an oasis in what has often looked and sounded like a desert. In a small corner of England farmland wildlife is able to thrive much as it did before pesticides were introduced. This is a complex and fascinating story, with a heady mix of hunting, farming, predation, parasites, disease and climate change. The way these factors have interacted tells us a lot about how lesser known species have fared and how they can be conserved for the future. Potts stresses the importance of these conservation efforts, as farmers respond to the needs of an extra three billion people worldwide, not just for food but for bio-fuels. Additionally, the pressures on farmland wildlife will further intensify in the coming years.
"It is always rewarding to read a book by someone who has spent a lifetime researching his subject matter. This is just such a book, and centres on the three partridges that have bred in Britain: the native Grey Partridge Perdix perdix, which receives the most emphasis, and the introduced Red-legged Alectoris rufa and Chukar Partridges A. chukar (the latter probably now extinct). But, as the author explains in his foreword: ‘This book is about far more than partridges. Mankind and partridges have evolved together, both ultimately dependent on grasslands… For thousands of years, both ate grass seeds… until cereals largely replaced them. Hundreds of species of plant and insect that partridges and other birds eat thrived on farms for thousands of years until the dawn of the pesticides era. Since then the long decline in partridge abundance has been a barometer for biodiversity over vast swathes of the northern hemisphere.’ With partridges as the focus, then, this book is largely about the ecology of arable farmland, discussing the procedural changes that have led to the massive loss of plant and animal life from our countryside over the past 50 years or so.
Starting his work in the 1960s, in what is now the Game & Wildlife Conservation Trust, and continuing to the present, Dick Potts has worked through this period of change on farmland, recording the declines in Grey Partridges and many other birds as pesticides progressively removed their food supplies. The Grey Partridge was one of the first species to be studied in this respect, and is still the best known. In pioneering work, the author and his colleagues used a combination of observations and measurements, mathematical modelling and replicated field trials to develop and test their ideas. By the 1980s, it was clear that Grey Partridges were declining in Britain because herbicides and insecticides were removing the insects needed by the chicks. The birds were producing insufficient young to offset the usual adult mortality, so that numbers declined. In Britain, there is now just a fraction of the Grey Partridges that were present in the 1960s, the species having disappeared totally from much of the country where it was formerly common. Moreover, these declines have been repeated throughout the farmlands of the northern hemisphere, wherever pesticides are used. The decline in numbers on British farmland removed the incentive on shooting estates to maintain hedges and other field boundaries and to control nest predators, which led to further collapse.
Another consequence of the decline of the Grey Partridge in Britain has been the switch in emphasis from wild game management, which led to many other benefits for farmland wildlife, to the current artificial mass-rearing of Common Pheasants Phasianus colchicus, which creates other environmental problems. The same holds for the introduced Red-legged Partridge, which has grown in popularity among the shooting community. It is now far more abundant than the Grey, again because it can also be readily reared and released. Through put-and-take shooting, these two aliens have now become the two most numerous gamebirds in Britain. Their current management effectively removes the impetus that landowners might once have had to manage their land in manner conducive to wildlife.
The author discusses every conceivable aspect of partridge biology, from evolution, geographical range and glacial history to all aspects of their ecology, including habitat and food needs, predators, parasites and life history. All these aspects are covered in far more detail than is usual in most bird monographs, and the author has done a great service in pulling all this information together. He develops the theme that predators which are now important to partridges, and may prevent them from increasing where other conditions are good, are commoner in the modern landscape than they otherwise would be, owing to the removal long ago of top predators, such as Eurasian Lynx Lynx lynx, Grey Wolf Canis lupus, Brown Bear Ursus arctos and lowland eagles. The story is not restricted to the situation in Britain, because, as the recognised world expert on the Grey Partridge, Dick Potts has travelled widely, both in Eurasia and in North America, interacting with other partridge biologists in different environments across the range.
Dick Potts has now had the opportunity to put his management prescriptions into practice on the Duke of Norfolk’s estate in Sussex, in which some land is managed specifically as nesting and feeding areas for partridges but some carefully chosen pesticides are still used on the cropped parts. The results are very impressive, for not only have Grey Partridges increased greatly, but so have many other farmland birds (including raptors), as well as wild plant and insect populations. This estate, which I had the pleasure of seeing recently, gives us a glimpse of how things used to be, and how they could be elsewhere today given more sympathetic land management. As the author himself concludes: ‘As a result of the desire to restore the numbers of a gamebird for shooting, a whole ecosystem has been brought back to life: rare arable flowers, insects, mammals and birds, including raptors’. It has been done under a combination of public funding (mainly from the Higher Level Stewardship scheme) and private funding from a caring and knowledgeable landowner. And what a staggeringly impressive result has been achieved within a few years. If you read only a bit of this book, make it chapter 10.
The author makes a plea for a targeted public–private partnership to co-fund partridge habitat management. ‘This would be economically efficient and unlike many agri-environment schemes currently operated, it would produce a spectacular amount of biodiversity… If agriculture is eventually going to result in biodiversity deserts, it would be better to have some oases.’ I agree with this sentiment.
In summary, I found this book very enjoyable, deeper and wider ranging than its title suggests, packed with information and insight, and written with feeling and first-hand knowledge. The text is enlivened by large numbers of colour photographs, graphs, and the occasional table. The book should appeal not only to the thoughtful birder, but to anyone with a love of the countryside."
- Ian Newton, www.britishbirds.co.uk, 25-02-2013