This book provides a comprehensive review of the evolution of traits associated with predation and predator defense for bats and all of their prey, both invertebrates (e.g. insects) and vertebrates (e.g. frogs), in the context of co-evolution. It reviews current knowledge of how echolocation and passive hearing are used by bats to hunt prey in complete darkness. Also it highlights how prey have evolved counter measures to bat echolocation to avoid detection and capture. This includes the whole range of prey responses from being active at times when bats are inactive to the use of acoustic signals of their own to interfere with the echolocation system of bats.

This book addresses the fundamental issues of predator-prey interactions, with an emphasis on predation among arthropods, which have been better studied, and for which the database is more extensive than for the large and rare vertebrate predators. The book should appeal to ecologists interested in the broad issue of predation effects on communities.

From the Foreword: "Predator-prey interactions are among the most significant of all organism-organism interactions....It will only be by compiling and evaluating data on predator-prey relations as they are recorded in the fossil record that we can hope to tease apart their role in the tangled web of evolutionary interaction over time. This volume, compiled by a group of expert specialists on the evidence of predator-prey interactions in the fossil record, is a pioneering effort to collate the information now accumulating in this important field. It will be a standard reference on which future study of one of the central dynamics of ecology as seen in the fossil record will be built." (Richard K. Bambach, Professor Emeritus, Virginia Tech, Associate of the Botanical Museum, Harvard University)

This thesis consists of two projects looking at different aspects of predatorprey relationships. The first project examines this relationship in the context of predator-prey coevolution and assumes that the cost for prey defense is variable. The second project looks at ecosystem shifts in the 1990s in the Gulf of Maine and the relative role of top-down verses bottom-up processes on controlling Calanus finmarchicus abundance. Predator-Prey Coevolution Predation can act as a selective pressure which drives prey to adapt a defensive trait to avoid attack. At the same time, predators can evolve a counter-defense which aids them in continued successful attacks. Allocation towards either trait can be costly, in the form of a decrease in fecundity. There is some evidence to suggest that, for the prey at least, cost can vary depending on the level of intraspecific competition. Here we investigated the effects of variable prey trait cost and genetic variability of the predator and prey, on the stability and dynamics of the system. We compared two models, one which assumed that cost of prey defense is fixed, and one that assumed that cost varies proportional to population density. We found that under most conditions, variable cost of prey defense is more stabilizing to the interaction than fixed cost. Gulf of Maine Ecosystem In the Gulf of Maine in the 1990s an increase in freshwater was associated with increased phytoplankton blooms, particularly in autumn. This in turn led to increased abundance in most copepods. Calanus finmarchicus, one of the most abundant zooplankton species in the region, demonstrated an increase in abundance in the earlier developmental stages but a paradoxical decrease in abundance of the later copepodid stages. At the same time, adult herring, which preferentially feed on late-stage C. finmarchicus, increased in abundance by one order of magnitude. Through ordinary differential equation models, we investigated whether increased presence of herring in the 1990s was large enough to contribute to the decline in late-stage C. finmarchicus. Additionally, we incorporated food-dependent growth into the later copepodid classes to investigate the impact of phytoplankton variation on the observed shifts in zooplankton abundance.

Predator-prey interactions are ubiquitous, govern the flow of energy up trophic levels, and strongly influence the structure of ecological systems. They are typically quantified using the functional response - the relationship between a predator's foraging rate and the availability of food. As such, the functional response is central to how all ecological communities function - since all communities contain foragers - and a principal driver of the abundance, diversity, and dynamics of ecological communities. The functional response also reflects all the behaviors, traits, and strategies that predators use to hunt prey and that prey use to evade predation. It is thus both a clear reflection of past evolution, including predator-prey arms races, and a major force driving the future evolution of both predator and prey. Despite their importance, there have been remarkably few attempts to synthesize or even briefly review functional responses. This novel and accessible book fills this gap, clearly demonstrating their crucial role as the link between individuals, evolution, and community properties, representing a highly-integrated and measurable aspect of ecological function. It provides a clear entry point for students, a refresher for more advanced researchers, and a motivator for future research. Predator Ecology is an advanced textbook suitable for graduate students and researchers in ecology and evolutionary biology seeking a broad, up-to-date, and authoritative coverage of the field. It will also be of relevance and use to mathematical ecologists, wildlife biologists, and anyone interested in predator-prey interactions.

When assuming the task of preparing a book such as this, one inevitably wonders why anyone would want to read it. I have always sympathized with Charles Elton's trenchant observation in his 1927 book that 'we have to face the fact that while ecological work is fascinating to do, it is unbearably dull to read about . . . ' And yet several good reasons do exist for producing a small volume on predation. The subject is interesting in its own right; no ecologist can deny that predation is one of the basic processes in the natural world. And the logical roots for much currently published reasoning about predation are remarkably well hidden; if one must do research on the subject, it helps not to be forced to start from first principles. A student facing predator-prey interactions for the first time is confronted with an amazingly diverse and sometimes inaccessible literature, with a ratio of wheat to chaff not exceeding 1: 5. A guide to the perplexed in this field does not exist at present, and I hope the book will serve that function. But apart from these more-or-Iess academic reasons for writing the book, I am forced to it by my conviction that predators are important in the ecological scheme. They playa critical role in the biological control of insects and other pests and are therefore of immediate economic concern.