Introduction

This book is about the impact of global climate change on birds, especially on their populations and conservation status, and what can be done about it. Birds are widespread in their distribution and occur in almost all environments. People enjoy watching them and many are easy to observe. As a result, they have long been studied by both amateur naturalists and professional scientists and they are amongst the best understood group of organisms. Data exist on the migration of birds from ringing (banding) studies and the direct observation of arriving and departing individuals, on their historical distribution from museum specimens, archaeology, literary and other sources, and on the timing and success of their breeding from nest recording that span many decades, or in the case of museum specimens, over a century. More recently, quantitative counting and mapping techniques have provided up to 50 years of standardised population and distribution data collection (Møller & Fiedler 2010). The internet is now being used to collect millions of sightings from bird watchers every year, whilst recent technological advances allow almost real-time tracking of migrating birds. These data provide an unparalleled opportunity first to understand the relationship between climate and species distributions and populations, and second to document changes in those distributions and populations occurring as a result of climatic change. Critically reviewing and documenting these kinds of evidence and what they tell us about the impacts of climate change on birds is one of the main purposes of this book, covered in Part 1.

Unfortunately, popular as they are, many bird species and populations are under threat. Of the 10 064 bird species identified around the world, some 13% are regarded as threatened by extinction within the next 100 years. Another 880 species are near-threatened (BirdLife International 2012a). Populations of habitat-specialists and shorebirds are in particular decline (Butchart et al. 2010). The threat of extinction which these species face is a real one; 103 species have been lost forever during the last 200 years. There is an urgent need for effective bird conservation to halt these trends. Whilst there have been significant conservation successes, these have only slowed, rather than halted, global rates of biodiversity loss (Butchart et al. 2010; Hoffman et al. 2010). Conservationists are winning occasional battles, but seem to be losing the war.