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Allee effects are broadly defined as a decline in individual fitness at low population size or density, that can result in critical population thresholds below which populations crash to extinction. As such, they are very relevant to many conservation programmes, where scientists and managers are often working with populations that have been reduced to low densities or small numbers. There are a variety of mechanisms that can create Allee effects, including mating systems, predation, environmental modification, and social interactions among others. The abrupt and unpredicted collapses of many exploited populations is just one illustration of the need to bring Allee effects to the forefront of conservation and management strategies. This book provides an overview of the topic, collating and integrating a widely dispersed literature from various fields: marine and terrestrial, plant and animal, theoretical and empirical, academic and applied.

This book is a collection of nineteen chapters where summaries of major ecological and evolutionary questions have been asked and responded using dragonflies and damselflies as study subjects. Each chapter is written by a well-respected scientist. The topics covered are: demography, population and community ecology, life-history, distribution, abundance, migration, conservation, applied use, predator-prey interactions, mating isolation, lifetime reproductive success estimates, reproduction vs. survival, parasite-host relationships, cryptic female choice, sexual conflict, territoriality, sex-limited colour polymorphisms, sexual size dimorphism, flight performance, and wing evolution. Each chapter puts forward new data and hypothesis in relation to further ecological and evolutionary questions.

This book reviews a variety of evolutionary themes and uses the small terrestrial orchids of Australia to introduce and illustrate these themes. Among the topics explored are the competing ideas of biologists who use the theory of natural selection when examining possible adaptations (such as the ability of orchid flowers to attract special pollinators) and those who reject this approach, including creationists as well as the late Stephen Jay Gould. Darwin’s own ideas on the topic are reviewed as his work on adaptive plant behavior, given that orchids provide examples of flowers with moving parts. In addition, the book outlines the ability of evolutionary biologists to trace the origin and subsequent modification of complex traits like the extraordinarily unusual flowers of certain orchids. The book also employs Australian orchids to demonstrate the challenges of determining what a species is and how to preserve the biodiversity that still exists in the world.

How we determine what is nature, what is wild, or even what in nature is worth protecting occurs through our human perspective. Whether it is a charismatic manatee or a majestic redwood, we care about and protect the things we love because they offer us something we value. To make this value relevant in the economic marketplace of competing choices, Wild Capital: Nature’s Economic and Ecological Wealth relies on the ecosystem services model, where nature’s value is determined through the services intact ecosystems provide to our well-being. As one of the recreation components of this model, this book uses ecotourism and the changing tourist dynamic, as well as our evolving relationship with nature, to demonstrate how we can assign a measurable worth to natural resources. If a developer or a policy maker can more equitably compare the capital asset value of development with that of wild nature, better decisions regarding economic and ecological trade-offs can be made. Wild Capital then incorporates the cultural bias we have for charismatic megafauna to link policy decisions regarding biodiversity and habitat conservation to those charismatic animals we care about so intensely. The five megafauna case studies provide solid evidence of the role charismatic species can play in protecting our planet’s biodiversity and ensuring our well-being long into the future.

The environment, and how humans affect it, is more of a concern now than ever. We are constantly told that halting climate change requires raising awareness, changing attitudes, and finally altering behaviors among the general public—and doing it fast. New information, attitudes, and actions, it is conventionally assumed, will necessarily follow one from the other. However, this approach ignores much of what is known about attitudes in general and environmental attitudes in particular—a huge gap lies between what we say and what we do. Solving environmental problems requires a scientific understanding of public attitudes. Like rocks in a swollen river, attitudes often lie beneath the surface—hard to see, and even harder to move or change. This book helps us read the water and negotiate its hidden obstacles, explaining what attitudes are, how they change and influence behavior. Rather than trying to change attitudes, we need to design solutions and policies with attitudes in mind. Heberlein illustrates these points by tracing the attitudes of the well-known environmentalist Aldo Leopold, while tying social psychology to real-world behaviors throughout the book. Bringing together theory and practice, this book provides a realistic understanding of why and how attitudes matter when it comes to environmental problems; and how, by balancing natural with social science, we can step back from false assumptions and unproductive, frustrating programs to work toward fostering successful, effective environmental action.

Mushrooms are the most wondrous inventions of the last billion years of evolutionary history on earth. Their overnight appearance is a pneumatic process, with the inflation of millions of preformed cells extending the stem, pushing earth aside, and unfolding a cap above the dewy grass. Once exposed, a mushroom's gills shed an astonishing 30,000 spores per second, delivering billions of microscopic particles into the air in a single day, cells that may be capable of spawning the largest organisms on the planet. Mushroom colonies burrow through soil and rotting wood. Some hook into the roots of forest trees and engage in mutually supportive symbioses; others are pathogens that decorate their food sources with hardened hooves and fleshy shelves. Among the staggering diversity of mushroom-forming fungi we find stranger apparitions including gigantic puffballs, phallic eruptions with revolting aromas, and tiny “bird's nests” whose spore-filled eggs are splashed out by raindrops. But it is the poisonous effects of a handful of fungal metabolites, and the powerful hallucinogenic qualities of others, which account for the central place of mushrooms in mythology and their commonest associations in Western culture. This book explains what mushrooms are (Chapter 1), how they work (Chapter 2), and what their underlying colonies do (Chapter 3); the harvesting and conservation of wild mushrooms and the cultivation of domesticated species are addressed in Chapters 4 and 5, the science of poisonous and hallucinatory fungi in Chapters 6 and 7, and deceptive claims about medicinal mushrooms in Chapter 8.

Hans Kruuk's previous Wild Otters was the first, and until now the only, book to cover both natural history and scientific research on behaviour and ecology of otters in Europe. The present book is a revision, rewrite, and update, now covering all species of otter in North America as well as Europe and elsewhere. Aimed at naturalists, scientists, and conservationists, in a personal style and with many illustrations, it describes the ecology and behaviour of some of the most charismatic and enigmatic mammals in our environment, as well as the research to understand their particular ecological problems. With over 650 references, there is up-to-date description of the most recent studies, including feeding ecology, foraging behaviour, relationships with prey species, and factors that limit populations, as well as social and breeding behaviour, molecular genetics, energetics, the problems of exposure to cold water, mortality, effects of pollution, and the serious, recent conservation problems. There are enchanting direct observations of the animals, as well as guidance about how and where to watch and study them, and what are the most serious questions facing researchers. From otters in the British and American lakes and rivers, to sea otters in the Pacific ocean, giant otters in the Amazon and other species in Africa and Asia, this book provides an enthusiastic, critical, and thorough approach to their fascinating existence, the science needed to understand it, and the threats to their survival.

All populations fluctuate stochastically, creating a risk of extinction that does not exist in deterministic models, with fundamental consequences for both pure and applied ecology. This book provides an introduction to stochastic population dynamics, combining classical background material with a variety of modern approaches, including previously unpublished results by the authors, illustrated with examples from bird and mammal populations, and insect communities. Demographic and environmental stochasticity are introduced with statistical methods for estimating them from field data. The long-run growth rate of a population is explained and extended to include age structure with both demographic and environmental stochasticity. Diffusion approximations facilitate the analysis of extinction dynamics and the duration of the final decline. Methods are developed for estimating delayed density dependence from population time series using life history data. Metapopulation viability and the spatial scale of population fluctuations and extinction risk are analyzed. Stochastic dynamics and statistical uncertainty in population parameters are incorporated in Population Viability Analysis and strategies for sustainable harvesting. Statistics of species diversity measures and species abundance distributions are described, with implications for rapid assessments of biodiversity, and methods are developed for partitioning species diversity into additive components. Analysis of the stochastic dynamics of a tropical butterfly community in space and time indicates that most of the variance in the species abundance distribution is due to ecological heterogeneity among species, so that real communities are far from neutral.

Habitat management is commonly used to maintain and enhance the biological interest of many areas of semi-natural habitat, where natural processes no longer create suitable conditions for desired species. Habitat restoration and creation is increasingly being used to increase the extent of ecologically important habitats in order to mitigate the impacts of human development. The modification of past management techniques and the introduction of new ones can provide additional benefits. This book describes the range of techniques used to manage land for biodiversity conservation. The opening sections discuss the general principles of habitat management, including decision-making, mitigating damaging effects of climate change, and monitoring the success of management. These are followed by a series of chapters which describe how to manage specific habitats: grasslands, dwarf-shrub vegetation and shrublands, forests, woodlands and scrub, freshwater wetlands, coastal habitats, arable land, and gardens, backyards, and urban areas. For each of these habitats the book discusses the main factors influencing their value for wildlife, highlights the key decisions that need to be made, and describes and compares the effects of individual management techniques.