Patterns Of Distribution Of Amphibians

Sweet, University of California, Santa Barbara; Michael J. Tyler, University of Adelaide, Australia; Zhao Er-Mi, Chengdu Institute of Biology, Peoples Republic of China

"The frogs, toads, salamanders, and newts that inhabit North America, numbering nearly 300 species, represent immense variation in form, habitat, distribution and ecology. This volume discusses the diversity of these animals in relation to the historical geography of the North American continent and portrays all of the formally recognized amphibian species to be found in the United States and Canada within a geographical context. Each species is presented with a color photograph, an account of its range, habitat and conservation status, and an up-to-date, full color range map that depicts its known occurrences in relation to the topography of the landscape. This volume reflects the enormous growth in interest about amphibians and increased intensity of scientific research into their biology and distribution that has occurred during the past two decades"--

Now reissued in paperback with an updated preface by the authors, Biology of Amphibians remains the standard work in its field.

This book analyzes different facets of anuran amphibian distribution in South America. We integrate alternative biological metrics employing cutting-edge methods to understand the dynamic processes underlying species distribution patterns. By using the modern biogeographic toolbox, we explore how richness gradients, phylogenetic diversity, functional diversity, and range size/endemism distribution of amphibians vary along the continent. Moreover, we present a robust proposal for priority areas for conservation of anurans in South America that maximizes representativeness of distinct biodiversity facets.

This study examined the question of whether a big island can be divided into many smaller islands with the same pattern of area-species curve as that of the complete island. To address this question, this study used data on the number and distribution of amphibians and reptiles on Puerto Rico and landbridge islands of the Puerto Rican Bank, which were fragmented from the big island about 10,000 years ago. In Puerto Rico, the data show correlations between the number of species and area available at different elevation levels and between species and area after removing effects of elevation. These patterns are different from the patterns of correlation between area and the number of reptiles and amphibians on 29 islands on the Puerto Rican Bank. The area-species curves of the elevationally and areally subdivided "islands" on Puerto Rico tend to have steeper slopes than the curves of the Puerto Rican Bank islands. Analyses of area and the number of those species on fragmented habitat islands at different elevations also indicated correlation between them. However, patterns of correlation seem not to be the same at each altitude. The slope of the area-species curve seems to decrease with increasing elevation levels. Other patterns of species distribution of Puerto Rico's herpetofauna are: there are linear relationships between the number of species and elevation, the number of species and distance from the coast, and the number of species and the species range areas. Multiple regression analyses of three variables: area, precipitation, and elevation, suggested that variation of species distribution in Puerto Rico is partly caused by interactions among these variables. Elevation plays an especially important role in explaining reptile and amphibian distribution. The rainfall variable had the least effect on determining herpetofauna diversity. The study results suggest that area-species correlation is a consequence of habitat heterogeneity on the island.

For over 350 million years, thousands of species of amphibians have lived on earth, but since the 1990s they have been disappearing at an alarming rate, in many cases quite suddenly and mysteriously. What is causing these extinctions? What role do human actions play in them? What do they tell us about the overall state of biodiversity on the planet? In Extinction in Our Times, James Collins and Martha Crump explore these pressing questions and many others as they document the first modern extinction event across an entire vertebrate class, using global examples that range from the Sierra Nevada of California to the rainforests of Costa Rica and the Mediterranean coast of North Africa. Joining scientific rigor and vivid storytelling, this book is the first to use amphibian decline as a lens through which to see more clearly the larger story of climate change, conservation of biodiversity, and a host of profoundly important ecological, evolutionary, ethical, philosophical, and sociological issues.