The Codex of the Endangered Species Act, Volume II


Book Description

The Endangered Species Act of 1973 (ESA) is one of the most cherished and reviled laws ever passed. It mandates protection and preservation of all the nation’s species and biodiversity, whatever the cost. It has been a lightning rod for controversy and conflicts between industry/business and environmentalists. In this volume, leading Endangered Species Act experts interpret and propose legislative and administrative changes to prepare the ESA for future challenges. They explore regulations on avoiding harm to and producing benefits for species, cooperation between state and federal agencies, scientific analyses, and the necessary politics to enact their ideas. This is a call to action to chart an enlightened future for the Endangered Species Act that embraces the nation’s moral commitment of 50 years ago to address species extinction constructively, mindful of biodiversity, and as a fixture among the nation’s values and needs. The interconnected web of life includes all living species that depend on each other for survival, us among them. The stakes—our very future—are too high to ignore.













Interpretation and Implications of Variability in Ecological Systems


Book Description

Numerous hypotheses have been proposed to explain the dynamics in abundance of individual species, how species interact, how communities assemble, and how interactions between biotic and abiotic processes shape ecosystem stability. Many if not most of these hypotheses find some degree of support, but often only within relatively narrow spatial and temporal ranges. This is because conditions vary over time and from place to place, and so the strength and extent of processes that were the focus of a given a hypothesis become altered by other forces. Ecologists have confronted variability from two perspectives; conceptual and statistical. Conceptually, spatial and temporal variability are now recognized as being scale dependent and hierarchical. Statistically, there are many models that ecologists readily use that account for the hierarchical and scale-dependence of variability present in many datasets. But linking the two perspectives into a meaningful understanding of what variability means in real systems has been much less successful. For example, it is common to see studies where the fixed effects of a generalized linear mixed model are reported, but very often random effects are completely ignored or, at best, given scant attention. The likelihood of this being a significant problem increases greatly in what are rapidly becoming more common studies that utilize datasets spanning long temporal and/or large spatial scales, or when extreme and often unpredictable events (gray and black swans) occur.




The Sonoran Desert Tortoise


Book Description

One of the most recognizable animals of the Southwest, the desert tortoise (Gopherus agassizii) makes its home in both the Sonoran and Mohave Deserts, as well as in tropical areas to the south in Mexico. Called by Tohono O'odham people "komik'c-ed," or "shell with living thing inside," it is one of the few desert creatures kept as a domestic pet—as well as one of the most studied reptiles in the world. Most of our knowledge of desert tortoises comes from studies of Mohave Desert populations in California and Nevada. However, the ecology, physiology, and behavior of these northern populations are quite different from those of their southern, Sonoran Desert, and tropical cousins, which have been studied much less. Differences in climate and habitat have shaped the evolution of three races of desert tortoises as they have adapted to changes in heat, rainfall, and sources of food and shelter as the deserts developed in the last ten million years. This book presents the first comprehensive summary of the natural history, biology, and conservation of the Sonoran and Sinaloan desert tortoises, reviewing the current state of knowledge of these creatures with appropriate comparisons to Mohave tortoises. It condenses a vast amount of information on population ecology, activity, and behavior based on decades of studying tortoise populations in Arizona and Sonora, Mexico, and also includes important material on the care and protection of tortoises. Thirty-two contributors address such topics as tortoise fossil records, DNA analysis, and the mystery of secretive hatchlings and juveniles. Tortoise health is discussed in chapters on the care of captives, and original data are presented on the diets of wild and captive tortoises, the nutrient content of plant foods, and blood parameters of healthy tortoises. Coverage of conservation issues includes husbandry methods for captive tortoises, an overview of protective measures, and an evaluation of threats to tortoises from introduced grass and wildfires. A final chapter on cultural knowledge presents stories and songs from indigenous peoples and explores their understanding of tortoises. As the only comprehensive book on the desert tortoise, this volume gathers a vast amount of information for scientists, veterinarians, and resource managers while also remaining useful to general readers who keep desert tortoises as backyard pets. It will stand as an enduring reference on this endearing creature for years to come.







The Conservation Biology of Tortoises


Book Description