This book explores the factors affecting the survival of small populations. As the human impact on Earth expands, populations of many wild species are being squeezed into smaller and smaller habitats. As a consequence, they face an increasing threat of extinction. National and international conservation groups rush to add these populations, species and sub-species to their existing endangered and threatened lists. In nations with strong conservation laws, listing often triggers elaborate plans to rescue declining populations and restore their habitats. The authors review these theoretical ideas, the existing data, and explore the question: how well do small and isolated populations actually perform? Their case study group is the song sparrows of Mandarte Island, British Columbia. This population is small enough and isolated enough so that all individuals can be uniquely marked and their survival and reproduction monitored over many generations. This is one of the strongest long-term ecological studies of a contained vertebrate population, now in its 31st year.

In the past two centuries, cowbirds have increased in numbers and extended their range across North America, while many of the native songbird species whose nests they parasitize to raise their young have declined. This timely book collects forty essays by most of the principal authorities on the biology and management of cowbirds. The book's goals are to explore the biology of cowbirds, the threats they pose to host species and populations, and the management programs that are being undertaken to minimize these threats. The book is organized into five sections, each with an extended editors' introduction that places the contributions in a broad, up-to-date setting. The sections cover: The changing abundance of cowbirds and the ways in which their numbers can be estimated. Host choice by cowbirds, the negative effects of cowbirds on particular host species, and the daily patterns of cowbird behavior. Behavioral interactions between cowbirds and specific host species. Patterns of cowbird abundance and host use across varying landscapes. Management programs designed to control cowbirds and protect threatened songbirds.