The history of recent wildlife extinctions and the widespread role of humans in these events are described. Conflicting views about the role of human numbers in wildlife declines are cited. There follows an outline of the book structure, highlighting the major proximal causes of declines in Britain , including persecution, urbanisation, agricultural intensification, climate change and disease, as detailed in subsequent chapters. There are also chapters on population growth, people's perceptions of population size and the implications for conservation A comparison of population densities in a range of countries reveals that the UK, especially England, has one of the highest densities in the world. The UK therefore provides an ideal study to investigate the impacts of human numbers on wildlife declines.