INTRODUCTION AND OBJECTIVES

From a conservation perspective, bird species represent some of the most tragic as well as encouraging examples of efforts to preserve the world's biodiversity. Rachel Carson's classic book Silent Spring (1962) was a resounding alarm showing how humans can destroy ecosystems and the avian diversity within them. Carson dramatically described the severe loss in songbirds and raptors (birds of prey) throughout the 1940s–1960s, offering convincing arguments for how indiscriminate use of organochlorine pesticides caused eggshell thinning and infertility.

There now are an estimated 9672 bird species on the planet, widely distributed across a great number of habitats. Little is known about the basic biology of most birds, a matter of concern given that 321 species are listed as ‘Endangered’ and another 182 as ‘Critical’ (IUCN, 2000) (Table 21.1). There have been 104 documented bird extinctions world-wide. One of the best known examples is the dodo, discovered in 1598 by Portuguese sailors on the island of Mauritius. With no known predators and lacking fear of humans, the dodo was slaughtered for its meat and was extinct by 1681. Commercial hunting a little more than a century ago reduced the passenger pigeon, then the most numerous bird species on Earth, to 250 000 birds by 1896. Most of this flock was subsequently destroyed on a single day. The last passenger pigeon died on 1 September 1915 at the Cincinnati Zoo and Botanical Garden, perhaps the only time in history when the exact moment an extinction occurred was recorded.