Trophic cascades—the top-down regulation of ecosystems by predators—are an essential aspect of ecosystem function and well-being. Trophic cascades are often drastically disrupted by human interventions—for example, when wolves and cougars are removed, allowing deer and beaver to become destructive—yet have only recently begun to be considered in the development of conservation and management strategies. Trophic Cascades is the first comprehensive presentation of the science on this subject. It brings together some of the world’s leading scientists and researchers to explain the importance of large animals in regulating ecosystems, and to relate that scientific knowledge to practical conservation. Chapters examine trophic cascades across the world’s major biomes, including intertidal habitats, coastal oceans, lakes, nearshore ecosystems, open oceans, tropical forests, boreal and temperate ecosystems, low arctic scrubland, savannas, and islands. Additional chapters consider aboveground/belowground linkages, predation and ecosystem processes, consumer control by megafauna and fire, and alternative states in ecosystems. An introductory chapter offers a concise overview of trophic cascades, while concluding chapters consider theoretical perspectives and comparative issues. Trophic Cascades provides a scientific basis and justification for the idea that large predators and top-down forcing must be considered in conservation strategies, alongside factors such as habitat preservation and invasive species. It is a groundbreaking work for scientists and managers involved with biodiversity conservation and protection.

There is something out there deep in the waters off the Southern coast of Australia. The search is on, in an unchartered area of a huge submarine abyss, the Bremer Canyon, for a predator that is big enough to eat a 3 metre great white shark.

From an Antagonistic to a Synergistic Predator Prey Perspective: Bifurcations in Marine Ecosystems is a groundbreaking reference that challenges the widespread perception that predators generally have a negative impact on the abundance of their prey, and it proposes a novel paradigm — Predator-prey Synergism — in which both predator and prey enhance abundance by their co-existence. Using this model, the text explains a number of issues that appear paradoxical in the case of a negative predator-prey relationship, including observed ecosystem bifurcations (regime shifts), ecosystem resilience, red tides in apparently nutrient depleted water, and the dominance of grazed phytoplankton over non-grazed species under high grazing pressure. This novel paradigm can also be used to predict the potential impact of global warming on marine ecosystems, identify how marine ecosystem may respond to gradual environmental changes, and develop possible measures to mitigate the negative impact of increasing temperature in marine ecosystems. This book approaches the long-standing question of what generates recruitment variability in marine fishes and invertebrates in an engaging and unique way that students and researchers in marine ecosystems will understand. Introduces a new paradigm, Predator-prey Synergism, as a building block on which to construct new ecological theories. It suggests that Predator-prey Synergism is important in some terrestrial ecosystems and is in agreement with the punctuated equilibria theory of evolution (i.e., stepwise evolution). Suggests a general solution to the recruitment puzzle in marine organisms Proposes a holistic hypothesis for marine spring blooming ecosystems by considering variability enhancing and variability dampening processes Asserts that fisheries will induce variability in marine ecosystems and alter the energy flow patterns in predictable ways

The potential consequences of a predator-prey predators tend to do that increase or maximize prey interaction are probably more serious, especially capture and that prey tend to do to avoid being for the prey, than are the consequences of most captured? The second theme emphasized the eco competitive or parasite-host interactions. For this logical approach to predator-prey interactions. reason, the adaptations and tactics that prey show What are the environmental constraints that in to the foraging manoeuvers of their predators, and fluence the evolution of structures and behaviors the counteradaptations of their predators, are often involved in predation and its avoidance? How do pronounced and even spectacular. Predation may in these factors combine to produce particular ,fssem fact be a critical determinant of both the behavior blages of predators and prey with common adapta of individuals and of the functional and taxonomic tions? The 18 papers presented at the symposium, composition of fish assemblages. This possibility and the ones published in these proceedings, re was a major factor leading to the organization of present the varied approaches that researchers have the Behavioral Tactics symposium. The obvious taken in addressing these questions. necessity of feeding, the wealth of information Several topics were common to many presenta available on food and energy budgets of animals tions: four of these in particular deserve at least both in the laboratory and field, and the approach brief mention.

Ecological heterogeneity can impact how energy flows from the base of the food web to top predators. In aquatic systems, apex predators are often highly mobile piscivorous fishes with the ability to respond to environmental change by modifying resource use to exploit multiple energy pathways. Further, the exploitation of pathways may be different among individuals, leading to intraspecific variation. I first tested for the presence of intraspecific variation in the apex fish predator, Lake Trout Salvelinus namaycush, in a 390 ha oligotrophic lake with two distinct basins. Differences in stomach contents, stable isotope niche space, and growth rates indicated that there is intraspecific variation across three habitats in this system; the upper basin pelagic, lower basin pelagic, and lower basin benthic habitats. I tested the effects of incorporating this variation and corresponding ecological heterogeneity (e.g., different temperatures, habitat-specific population sizes) on consumption estimates of kokanee (lacustrine Sockeye Salmon, Oncorhynchus nerka) derived from bioenergetics models. I assessed two bioenergetics modeling approaches; one lake-wide model, and one ecologically partitioned model that accounted for differences in Lake Trout diet compositions, growth, and population sizes across habitats. The ecologically partitioned model produced kokanee consumption estimates 30% lower than the lake-wide, unpartitioned model, which produced an estimate that exceeded the number of kokanee stocked in the system. Incorporating ecological heterogeneity and intraspecific variation into these bioenergetic models yielded valuable insights on the foraging patterns of a top predator across habitats. This more nuanced understanding of foraging dynamics could provide critical information to guide multispecies fisheries management by clarifying how managed species interact and in which habitats those interactions create management challenges.

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.