Pollination has been a quintessential part of popular natural history for as long as any of us, or our parents or our grandparents, can remember, and the sight of insects busying from flower to flower holds a quite unabated fascination today. Awareness of the need for pollination of the date palm stretches back into classical antiquity, but general recognition of the significance of pollination, and the importance of flower-visiting insects, had to wait for the scientific reawakening which gathered pace from the closing decades of the seventeenth century onwards. As time went on, other agents of pollination – wind, water, birds and bats – were found to play a part. One of the main reasons for the enduring appeal of the flower-insect relationship must be that it is so fundamentally one in which both partners benefit. In our present go-getting age we can sometimes be more conscious of how the partners exploit one-another’s services (and indeed there are some examples of very one-sided exploitation between flowers and their visitors). But in some ways this only adds to its appeal, and to the intellectual challenge of elucidating how the flower-pollinator relation has come into being, and how it is maintained in the competitive world of natural selection.
The New Naturalists already include The Pollination of Flowers, as No. 54 in the series. That book was published in 1973, near the beginning of a resurgence of interest in pollination biology. A period of sixty years or so, from the publication of Knuth’s monumental compendium in the early years of our century until about 1965, can be seen with hindsight as a rather unproductive time for pollination research. Some notable contributions were indeed made, but the subject was something of a backwater from the mainstream of biological progress. Over the last thirty years all that has changed dramatically. Not only has pollination biology emerged as a dynamic research field, but it has taken on a wholly new complexion. The cause of this renaissance and the flood of new papers on pollination has been an explosion of interest in the ecology and evolution of pollination, and the implications of this for many general aspects of the ecology, evolution and genetics of populations. The Pollination of Flowers recorded the beginnings of this upsurge of new interest. Over the last three decades, pollination biology has contributed major insights into the way plant populations function and it has given us a much deeper understanding of how plants have evolved. It has also influenced our perceptions on the evolution of social insects, and has played a major part in developing current ecological and evolutionary theories. These wider implications have kept pollination studies at the forefront of ecology. This in turn has rekindled interest in the more ‘classical’ observational and descriptive aspects of pollination and these too have advanced significantly, so we see today a buoyant and active subject advancing on many fronts.
When the idea of updating The Pollination of Flowers was suggested in the late 1980s it soon became obvious that we should have to rewrite the book completely. This is the result. Taking the earlier book as a starting point, the first and largest change was to invite a third author, Andrew Lack, to join the team specifically to cover the work on ecology and evolution that had been done since 1973. The three of us together were responsible for the shape and character of the present book, which differs from its predecessor in two main ways. First, we have shifted the emphasis towards a more functional view of the benefits and costs of the pollination relationship to flowers and their visitors, and the ways in which these interact. Second, while we have written the book from a primarily ‘British Isles’ standpoint, we have taken a more liberal view of the New Naturalist brief ‘…to interest the general reader in the wildlife of Britain…’ than we did in the earlier book. The preface to The Pollination of Flowers called pollination ‘an obstinately international subject’, and it has become ever more so as years have passed. Much of the research on pollination biology since 1970 has been done in North America, with a significant quantity from tropical countries around the world and from the southern hemisphere. The results, along with those of continuing study in Europe, are often relevant to all pollination relationships, and to understanding the pollination of our native plants here in Britain. Added to that, travel has become easier and we have surely all become more international in outlook in the last quarter century. The countries of continental Europe, the Mediterranean coast, and increasingly North America, Africa and places even farther afield, are coming within the experience of holidaying (and sometimes working) Britons – part of our ‘home range’. Perhaps even more significant is the much wider awareness of the world’s flora and fauna generally brought about by the superb natural history films which have become so regular a feature of television since David Attenborough’s Life on Earth.
Like its predecessor, this book is a selective distillation of a vast subject. We hope it gives a reasonably rounded view of pollination biology in the 1990s – and that it will give pleasure and interest to many readers. We realise that some people may not want to read the chapters in the order in which they appear here; we have tried to put as few difficulties in their way as possible. Some technical terms are inevitable, some are useful shorthand for otherwise cumbersome circumlocutions; we have tried to keep them to a minimum, and those that we use are explained in Chapter 2 or at their first appearance in the text. As in The Pollination of Flowers we have given numerous references to the scientific literature, for the benefit of readers who want to know more or to go to the source of statements in the text. We hope that will not detract from the readability of the book. Sources of unpublished information are ackowledged by name and initials with no date. For plant names, we have followed Stace’s New Flora of the British Isles (1991) for British plants and Flora Europaea (Tutin et al., 1964–1981) for other European plants; for non-European plants we have followed the published source quoted. Insect names follow the second edition of Kloet & Hincks’s A Check List of British Insects (1964–1978).
In writing The Natural History of Pollination, M.C.F.P. was primarily responsible for Chapters 1, 2, 6, 7 and 9, P.F.Y. for Chapters 3, 4, 5, 8, 10, 11, and 13, and A.J.L. for Chapters 12, 14, 15 and 16. Throughout, we have all read and criticised each others chapters, and we have seen the book very much as a joint venture. Line drawings not otherwise acknowledged are original, mostly taken from The Pollination of Flowers. Unacknowledged photographs are by M.C.F.P.; other photographers are acknowledged in the captions.
Many other people have contributed directly or indirectly to the writing of this book, and we are grateful to all of the friends and colleagues, too many to name individually, with whom we have discussed pollination, or who have sent reprints and sometimes unpublished manuscripts and observations. We are particularly indebted to Prof. Christopher Cook, Dr Sally Corbet, Dr Paul Cox, Dr James Cresswell, Prof. Bertil Kullenberg, Dr Anders Nilsson, Dr Börge Petterson and Dr Jonathan Silvertown, all of whom read and commented on parts of the text in draft. Their help was of great value. M.C.F.P. remembers with appreciation the fine collection of living plants (some portrayed here) built up by the late Prof. John Caldwell in Exeter, and is grateful to Gavin Wakley for technical help with the scanning elecgtron micrographs. A.J.L. acknowledges a special debt to Dr Quentin Kay and Dr Peter Gibbs for discussions on many subjects, and to Derek Whiteley for contributing such splendid line drawings to Chapters 12 and 14. We have greatly appreciated the patience and helpfulness of the HarperCollins natural history editors, and especially the cheerfulness, and efficiency of Isobel Smales through the long haul of turning a pile of evolving typescript and a large pool of assorted photographs into an almost finished book, and of Liz Bourne who coped with the final stages of bringing The Natural History of Pollination into the world. Finally, each of us owes a debt to his co-authors. Working together on this project has been a stimulating and enjoyable experience. We hope we can share that stimulus and enjoyment with our readers.
M.C.F.P.
P.F.Y.
A.J.L.
Most of the photographs of insects visiting flowers were taken in Devon (a few in the Channel Islands and elsewhere) between 1964 and 1970. At that time small transistorised electronic flash units and 35 mm single-lens reflex camera with pentaprisms and instant-return mirrors were just becoming widely available, and had opened up new possibilities for insect photography in the field. The photographs reproduced here were taken on Ilford Pan F film, using Praktica and Pentax cameras, either with a 50 mm Tessar or 55 mm Takumar standard lens on extension tubes, or with the Pentax 55 mm macro lens (a rather longer lens is easier for work of this kind, but I did not have one at the time). For the earlier pictures a small standard flash unit (Mecablitz) was used, giving directional lighting; a number of the later pictures were taken with a Minicam ringflash. Ringflash lacks the ‘modelling’ given by a directional light source, and shiny convex surfaces (in which insects abound) tend to reflect distracting circular images of the flash tube, but for recording insect behaviour in the field these disadvantages are outweighed by the advantage of even and predictable lighting without strong shadows; what you see in the viewfinder is what you get on the film! The successrate in field photography of this kind (as in many sporting activities) is heavily dependent on practice. Obviously some subjects are much easier than others. Over all, perhaps 50% of exposures yielded reasonably framed and acceptably sharp negatives, but the really worth-while pictures probably averaged only two or three on a film. However, it is a rewarding activity, to be recommended. With modern improvements in fast films, much field insect photography can now be done without flash.
M.C.F.P.