The dynamics of arthropod predator-prey systems

Anim . Behav ., 1979, 27, 1278-1280

BOOB REVIEWS Neuronal Plasticity. Edited by CARL W . COTMAN. New York : Raven Press (1978). Pp . 335 . Price $32 . 50 . The significance, extent and cellular mechanisms of nervous system plasticity are questions at the centre of contemporary neurobiology. Carl Cotman is one of the more prolific of the middle generation of neurobiologists, and it would have been reasonable to expect that a book edited by him on such a central topic would provide valuable insights into both theoretical issues and experimental approaches at a number of different levels from the biochemical to the behavioural . Indeed, both the bookjacket and the Editor's Preface promise just this . If it had been achieved, Neuronal Plasticity would have been a useful addition to the host of symposium volumes and collections which have appeared in recent years . However, it has not . In a symposium volume one could expect a certain degree of incoherence, and perhaps condone it, but when as in this case one assumes that the editor has actually gone out to solicit papers from key workers in the field on the theme of plasticity, one should expect a degree of coherence and an attempt at a synoptic overview . Far from it ; with no obvious rationale for their choice, there are thirteen disparate chapters which range from rather specialized research reports to attempts to survey a small area ; there is a unified index, but no general reference list and no apparent cross referencing between the authors, who seem to have been unaware of one another's existence. This is not to deny the value of individual chapters ; there are a number of good chapters on regeneration, sprouting, trophic effects and synaptic remodelling, a nice account by Merrill & Wall of their work on deafferentation and silent synapses, an integrative paper by Goldman & Lewis on the developmental biology of brain damage and experience, and a typically perceptive and somewhat abrasive discussion by Pettigrew entitled `The paradox of the critical period for striate cortex' . The editor himself, together with Nadler, contributes on reactive synaptogenesis in the hippocampus, a useful paper which does attempt some integration of events occuring after lesions of hippocampal connections, both in terms of a temporal analysis and in the relationship of cellular to behavioural phenomena . However, in the absence of any attempt at an overview, the reader will in all probability be left in considerable doubt as to exactly what neurobiological issues the concept of plasticity, as implicitly used in the book, is intended to address . Are the events of developmental plasticity a consequence of experience, environmental modulation and learning, or indeed of epigenetic effects, of the same kind as the regenerative processes which follow the lesioning of brain regions or fibre pathways in the adult? Or is regeneration after insult not a useful model for more subtle brain changes ? Is learning itself a special case of developmental plasticity and should one expect it to have similar cellular and biochemical correlates? It would be nice to know what the editor or authors thought about these issues . Failing this, the publication of the present book seems to me to owe more to the opportunism of the editor and publishers and the selfinterest of authors anxious to add to their publication lists (a fault, if it be one, from which we all tend to suffer, let me hasten to add) than any burning desire to com1278

municate new insights . The only answer, for individuals or libraries, is to refrain from buying it . STEVEN ROSE

Brain Research Group, Open University, Milton Keynes, MK7 6AA . The Dynamics of Arthropod Predator-Prey Systems . By MICHAEL P . HASSELL . Princeton : Princeton University Press (1978). $16.00 cloth ; $6.95 paper. The Princeton series `Monographs in Population Biology' has provided a forum for leading ecological and evolutionary biologists for over a decade . In Volume 13, Michael P . Hassell develops an extraordinarily clear and accessible series of mathematical models relating particular components of predator-prey interactions to system stability . The greater portion of the book addresses those insect communities where a host species is attacked and ultimately killed by an insect parasitoid . For this simple system, difference equations modelling predator and prey population growth can be developed with varying degrees of sophistication in order to examine the assumptions inherent in Nicholson's and Bailey's classic model . Hassell shows how variation in such components as the functional response of predator attack rate to prey density, foraging patterns, interference between predators, and switching of preferred prey with prey frequency can contribute to stability. In most cases, he presents ample biological justification (drawn from both laboratory and field results) for his models . The book concludes with a discussion of strategies of biological control of insect pests that incorporates the lessons learned in the previous chapters . Readers of Animal Behaviour will be pleased to find that specifics of the behaviour of predators are allimportant in determining the mathematical stability of these models. For example, Hassell shows how predators that tend to aggregate in areas with high prey density can cause a two-species model to be more stable than a similar model in which predators search for prey at random . Similarly, predators that interfere with each other's searching efficiency promote stability . Again, many examples of these types of behaviour are drawn from the insect literature and presented with the modelling . Incidentally, the mathematics itself is not difficult as the more complex arguments are relegated to an appendix . I found one aspect of the book in need of further comment. In developing a simple single-species model early in the book, Hassell notes that the value of a parameter that locates the population on a continuum ranging from scramble to contest-type population regulation has a large effect on the stability of that population. He further notes that the small amount of data available places most real insect populations at the contest end of the range . Population self-regulation of this type would potentially act as a strong stabilizing force and yet, in further discussions, Hassell states that prey population self-regulation is assumed to be of the scramble type ; the most potentially destabilizing response to density. This is done in part to simplify the mathematics of single-species systems, a necessary prerequisite to advancement to tractable multi-species models. Still, I would have liked to have seen some further discussion about the interaction between the types of responses



BOOK REVIEWS a prey population can have to its own density and its response to the presence of a predator . In summary, let me reiterate my overall praise of this book and recommend it strongly to anyone interested in predator-prey interactions . DAVID E . MCCAULEY Department of Biology, University of Chicago, Chicago, Illinois 60637 .

Behavioural Ecology : An Evolutionary Approach. Edited by J. R . KREBS & N . B . DAVIES . Sunderland, Mass. : Sinauer Associates, Inc. (1978) . Pp . xii + 494. Price $34.00 cloth, $17 .50 paper . Some years ago, a prominent biologist dared to ask `Is ethology dead'? The mere question struck terror into my heart since I was about to offer myself to an ever more ruthless job market . The book Behavioural Ecology : An Evolutionary Approach, edited by J. R . Krebs and N. B . Davies, should offer current students of behaviour more reassurance, since if ethology has died, it appears to have left a legitimate heir : behavioural ecology . Behavioural ecology is definitely alive and well in Britain . (Of the 14 contributors to this book, 10 are at British universities .) I was recently told that `the people at Sussex think up all the good ideas, and the people at Oxford test them' . Although the exchange may be more complex than that, the fact remains that much of the current excitement in behavioural ecology is due to an unprecedented interplay of simple theories and elegant experiments . Having inherited Niko Tinbergen's talent for designing relevant experiments, the British behavioural ecologists are now busy testing kinship and optimization theories of behaviour . Unlike many theories in other branches of ecology, theories in behavioural ecology tend to be both simple and testable. Despite frequent warnings from population geneticists that evolution may not maximize fitness, or anything else, behavioural ecologists who are experimentally testing quantitative optimization models are finding that many animals may maximize their energy intake while foraging (Krebs, Chapter 1) or minimize their risks of predation by living in groups (Bertram, Chapter 3), or maximize their reproductive success when searching for mates (Parker, Chapter 8). Also defying the warnings of population geneticists, Emlen (Chapter 5) finds that kinship theory may be useful for interpreting the evolution of cooperative breeding . As flawed and simple as optimization models are, they nonetheless seem to be helping behavioural ecologists ask better questions and design experiments to answer those questions. The chapters on the ecology of sex (Maynard Smith, Chapter 6) and sexual selection (Halliday, Chapter 7) serve as models of clear writing and clear thinking . Perhaps, now that some of the issues have been clarified, these areas will begin to accumulate some experimental tests of all these clever hypotheses . Still, too many hypotheses are better than too few . The area of habitat selection seems to have loads of data, but no hypotheses to test . It is not that Partridge's review of habitat selection (Chapter 12) is inadequate, but rather that there are no new ideas to review . Habitat selection is one area of behavioural ecology that is almost devoid of theory and, not surprisingly, also devoid of the excitement which characterizes most of this rapidly expanding field .

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The 45 pages of references at the end of the book reflect the recent expansion of behavioural ecology . A quick survey indicated that almost two-thirds of the papers cited have been published in the last 10 years, and nearly one-half in the last 5 years! (By and large, there are few referencing errors, though I am puzzled by the reference to Smith 1774 on page 55.) I cannot promise that reading Krebs and Davies' book is an optimal strategy for finding out what is happening in behavioural ecology, but I can assure you that it is a pleasant way to do so . H . RONALD PULLIAM Museum of Northern Arizona, Flagstaff, AZ 86001 . Contrasts in Behavior : Adaptations in the Aquatic and Terrestrial Environments . Edited by E . S . REESE & F . J. LIGHTER. New York : John Wiley (1978) . Pp. 406. $27 .50. This volume grew out of a symposium organized by Ernst Reese and held at an Animal Behavior Society meeting in May 1975 . The contributions cover a wide range of topics, including hermaphroditism and unisexuality in vertebrates, comparisons of parental behaviour and lekking in birds and fishes, and discussions of communication, agonistic behaviour, feeding ecology, and social organization in fishes and other vertebrates . The stated purpose of the volume is to `instill in the reader an appreciation of the insights that a broad comparative perspective can provide in his own area of research' . Specifically, the authors, almost all experts on the behaviour of fishes, were asked to survey the review literature to seek out useful analogies between the behaviour of their own organisms and that of other vertebrates . Like many such enterprises, the idea is appealing in concept, but has produced distinctly mixed results . The chief danger in such an approach is that the use of a broad brush may produce a picture that is attractive at a distance, but appears on closer inspection to be lacking in detail. Like many symposium volumes, the book is out of date because of a long publication delay ; few authors cite papers published after 1975 . The volume also suffers from contributions that are uneven in both approach and quality . For example, Burney LeBoeuf's paper comparing social systems of marine and terrestrial carnivorous mammals seems out of place in a volume devoted almost entirely to fishes . Some authors present broad-based reviews ; others concentrate on their own research on fishes, with only superficial treatment of other groups . The paper on lekking by Paul Loiselle & George Barlow may be the one most likely to influence future research. They make a good case for the existence of communal male display groups in fishes analogous in form and function to avian and mammalian leks. However, they may have done a disservice to their animals by entitling their paper 'Do fishes lek like birds?' . Their discussion makes clear that different selective pressures have led to the evolution of lek-like behaviour in fishes and terrestrial vertebrates. Loiselle & Barlow sometimes drift into unsupported speculation . For example, they state that females in unpredictable environments should mate with several males to increase offspring variability, but I know of no evidence demonstrating that females can increase fitness in this way. The authors also argue that characters affecting male mating success should be correlated with