Book excerpt: These superb collections of field recordings and descriptions offer unparalleled access to the sounds and calls of numerous popular and less well known birds and amphibians. Each book and CD provides an introduction to the sound repertoire of species living in eastern and central North America--a variety of calls from each species are included, along with an in-depth description and explanation of their significance. In addition to color photographs of the most common species, the text offers a fascinating look at the science of avian and amphibian calls, making these guides indispensable aids for the outdoor enthusiast.