Sometimes the discipline of conservation biology seems a little bit like fiddling while Rome burns. Oswald Schmitz's compact and accessible book reminds that the application of the fundamental principles of ecology can, and should be, central to efforts to maintain diverse and functioning ecosystems. The text assumes very little prior knowledge of the discipline, and yet manages to remain informative and authoritative even for specialists. This is not a text book in the conventional sense, but it would be eminently suitable as the basis for an undergraduate course on the science underpinning environmental conservation; it will be equally approachable for a general non-specialized readership. Schmitz, quite rightly in my opinion, downplays the ‘small population’ single-species focus of much contemporary conservation biology in favour of an ecosystem-focused approach that stresses interdependencies and the link between diversity and ecosystem function. Ecological principles and tools such as the dynamics of population growth or age-structured demographic models are introduced alongside the environmental issues to which they relate, and the text is liberally peppered with real-world applications and case studies. The final chapter should be essential reading for ecologists wishing to inform and influence environmental policy. I will certainly use this book in my teaching, and I recommend it wholeheartedly.