The boreal forests of Canada and Alaska represent 25% of the earth's remaining intact forests, over half of the North American bird species breed there, and 3 to 5 billion birds are estimated to migrate from the Canadian boreal region each fall. Unfamiliar to many, these hinterlands of the north are seriously threatened. Oil and gas extraction has a footprint of 46 million ha as of 2003, more than 31 million ha have been logged since 1975, and hydropower projects have flooded millions of hectares of terrestrial habitat in Quebec. These are examples of the stark facts presented in this book on the status of North America's boreal forests. Complacent or ignorant, most of us take these forests for granted.
The book emphasizes the linkages and importance of boreal birds to the avifauna of the United States, Mexico, Central America, the Caribbean, and South America. The book is not an attempt to dissuade concerns in other areas but simply emphasizes “us too” regarding the threats that so many birds and regions are experiencing from habitat and landscape changes due to human and industrial development.
The book is an eclectic mix of nine chapters with 38 contributors. Several chapters are broad in scope (chapters 1, 2, 3, and 7), whereas others are narrowly focused on specific species (chapters 4 and 9; see below). Chapter 5 on the Ontario breeding bird atlas and chapter 6 on passerine banding data from the eastern United States are brief reviews of available data. By contrast, chapters 7 and 8 provide a fascinating analysis and overview of wintering distributions of boreal migrants in North, South, and Central America and in the tropical Andes, respectively.
Wells (chapter 1) and Wells and Blancher (chapter 2) set an impressive stage on the threats to North American boreal forests and the important role that boreal birds have in the global conservation of birds. Wells emphasizes that this “volume highlights new research that is illuminating the importance of the region to North America's avifauna and the complexity of avian ecological connectivity between the boreal forest region and ecoregions throughout the Americas.” This book is an excellent complement to his previous publications on boreal birds and his contributions to the boreal songbird initiative (see WWW.borealbirds.org). Despite all of the habitat changes in Canada's boreal forest, there are some positives, such as the 45 million ha of new protected areas since 2000 and improvements in forest stewardship.
The book contains many thought-provoking analyses on where the 1.65 to 3 billion birds that breed in North America's boreal forest overwinter. For instance, chapter 7 includes an estimate that 66 species and more than a billion landbird individuals that breed in the Canadian boreal forest overwinter in the continental United States. In comparison, 115 species and 680 million individual landbirds overwinter in Mexico. Chapter 8 approximates that 123 species of boreal migrants overwinter in the Tropical Andes of Bolivia, Colombia, Ecuador, Peru, and Venezuela. These include 28 species with over half and 11 species with most of their winter distribution in that region.
Even though the chapters on the Surf Scoter (Melanitta perspicillata) and Rusty Blackbird (Euphagus Carolinas) seem out of place in a book primarily focused on broad issues of boreal bird species, both are interesting. Chapter 4, on the Surf Scoter, exemplifies the difficulty in studying a species that nests in the remote landscapes of the far north. It also highlights how little we know about many of these species and how satellite transmitters or other technology will aid in improving this knowledge. Chapter 9, on the Rusty Blackbird, is justified because it may have experienced the greatest decline of any North American landbird. Breeding Bird Survey data suggest a decline of 12.5% year-1 over the past 40 years, or a cumulative decline of 95%. The chapter is an excellent summary of the evidence for the decline, hypotheses on its causes, and recommendations for future research and management.
The book is not error free, but the errors are few. Numerous awkwardly written sentences could have been more tightly edited for better clarity. Additional illustrations and better illustrations would have improved the readability of the chapters.
In general, this volume is a substantial contribution to our understanding of North America's boreal birds and, especially, their importance in other parts of the Americas. The opening chapters will be an eye-opener to many ornithologists not familiar with boreal regions. The book will be essential to ornithologists with an interest in boreal bird species and especially appealing to those interested in the distribution of boreal species throughout the Americas. Editor Wells should be commended for his guidance and perseverance in the improvement of our knowledge and communication on boreal birds. With its reasonable price, the book belongs in university libraries.
