Spend a day hiking in the Sonoran Desert, and you may spot an unusual sight: a lizard sprinting on two legs! Collared lizards reach speeds of up to 16 miles per hour while racing on their hind legs to catch prey or escape predators. Eye-catching photos, fascinating facts, and explanations of adaptations will keep young readers glued to the pages of Collared Lizards!
The Eastern Collared Lizard (Crotaphytus collaris) has experienced extensive population declines over the past half century in the Ozark Mountains. Previous research suggests that glade habitat degradation through woody vegetation encroachment is an important factor resulting in population declines. In this dissertation I used information on time-energy budgets to investigate the link between habitat degradation and shifts in life history traits likely resulting in population declines of Eastern Collared Lizards (Crotaphytus collaris) in the Ozarks. In chapter one, I addressed the influence of dense woody vegetation encroachment on age-specific growth, body size, body condition and reproduction of C. collaris in northern Arkansas. Results from chapter one suggested that populations in encroached glades (defined by dense woody vegetation encroachment) experienced reduced body growth rates, delayed age of maturity, reduced clutch sizes and a nearly 50% decline in annual population fecundity rates. In chapter two, I investigated the role of behavior (postural adjustment) on the thermal ecology estimates of surface-active lizards using thermal data of C. collaris in one of my study populations. I used the data in chapter two to determine the most suitable methodologies to investigate the thermal ecology of C. collaris in northern Arkansas. In chapter three, I investigated the thermal sensitivity of digestion in C. collaris. Results in chapter three suggested that C. collaris digestion performance is affected by temperature, primarily through effects on passage times and voluntary feeding rates. In chapter four, I used results from the previous three chapters to erect several mechanistic hypotheses aimed at identifying the link between glade encroachment and reduced reproductive rates in C. collaris. Data in chapter four suggest C. collaris in encroached glades experience reduced environmental heat loads, shorter activity-times and less time-at-temperature suitable for digestive processing. The reduction in time-at-temperature for digestive processing resulted in lower energy available for growth and reproduction (4̃1%), which led to a near 50% decline in energy devoted to reproduction (# of eggs). Results from this dissertation provide a compelling explanation to the mechanisms causing a shift in life history traits that appear to play an important role in population declines of C. collaris in the Ozarks.
The collared lizard (Crotaphytus collaris) is distinguished by the two black collars around its neck. Adult males have bright green scales as well as tan, olive, brown, bluish and yellow scales. Females are less colorful than the males. Both have whitish bellies and large heads. Collared lizards are one of only a few lizards that are able to run using only their hind legs. They are very fast with a stride up to three times their body length. They also do not lose their tail very easily, but if they do, it does not grow back.In this book, you will know more about collared lizards and its interactions
The most thorough treatment of lizards of the United States and Canada when first published in 1946, Handbook of Lizards has become a landmark among herpetologists and lizard specialists. Hobart M. Smith spent years compiling and organizing information on 136 species of lizards for this classic study. With more than 300 illustrations, including black-and-white photographs, labeled drawings, range maps, and illustrated keys, this volume serves as a still-relevant and convenient reference guide to the study of North American lizards. Darrel Frost, a prominent lizard specialist, provides a foreword for the 1995 paperback edition that underscores the work's relevance for herpetology today. In the first section, Smith covers in concise fashion the habits, life history, habitats, methods of collection and preservation, and structural features of lizards. The second section of the book considers each species under topics that are conveniently arranged for studying both living lizards and laboratory specimens: range, type, locality, size, color, scalation, recognition characters, habitat and habits, and references. Smith also discusses problems for further study and gives recommendations for special investigations of each species. The book concludes with an extensive bibliography.
"Texas offers the opportunity to observe lizard diversity like no other part of the country," writes Laurie J. Vitt in the foreword to Texas Lizards. From the moist eastern Piney Woods to the western deserts, lizards can be found in every part of Texas. The state has forty-five native and six naturalized species of lizards, almost half of the 115 species that live in the continental United States. Yet Texas lizards have not received full coverage in regional field guides, and no other guide dedicated solely to the state's lizards has ever been published. Texas Lizards is a complete identification guide to all fifty-one native and established exotic lizard species. It offers detailed species accounts, range maps, and excellent color photographs (including regional, gender, and age variations for many species) to aid field identification. The authors, two of the state's most knowledgeable herpetologists, open the book with a broad overview of lizard natural history, conservation biology, observation, and captive maintenance before providing a key to Texas lizards and accounts of the various lizard families and species. Appendices list species of questionable occurrence in Texas and nonestablished exotic species. Informational resources on Texas lizards, a map of Texas counties, a glossary, a bibliography, and indexes of common and scientific names round out the volume.
An innovative introduction to ecology and evolution This unique textbook introduces undergraduate students to quantitative models and methods in ecology, behavioral ecology, evolutionary biology, and conservation. It explores the core concepts shared by these related fields using tools and practical skills such as experimental design, generating phylogenies, basic statistical inference, and persuasive grant writing. And contributors use examples from their own cutting-edge research, providing diverse views to engage students and broaden their understanding. This is the only textbook on the subject featuring a collaborative "active learning" approach that emphasizes hands-on learning. Every chapter has exercises that enable students to work directly with the material at their own pace and in small groups. Each problem includes data presented in a rich array of formats, which students use to answer questions that illustrate patterns, principles, and methods. Topics range from Hardy-Weinberg equilibrium and population effective size to optimal foraging and indices of biodiversity. The book also includes a comprehensive glossary. In addition to the editors, the contributors are James Beck, Cawas Behram Engineer, John Gaskin, Luke Harmon, Jon Hess, Jason Kolbe, Kenneth H. Kozak, Robert J. Robertson, Emily Silverman, Beth Sparks-Jackson, and Anton Weisstein. Provides experience with hypothesis testing, experimental design, and scientific reasoning Covers core quantitative models and methods in ecology, behavioral ecology, evolutionary biology, and conservation Turns "discussion sections" into "thinking labs" Professors: A supplementary Instructor's Manual is available for this book. It is restricted to teachers using the text in courses. For information on how to obtain a copy, refer to: http://press.princeton.edu/class_use/solutions.html
Introduction: The evolutionary study of social behavior and the role of lizards as model organisms / Stanley F. Fox, J. Kelly McCoy and Troy A. Baird -- Variation among individuals. Introduction / Peter Marler. Intra- and intersexual variation in social behavior : effects of ontogeny, phenotype, resources, and season / Troy A. Baird, Dusti K. Timanus and Chris L. Sloan. Evolution and maintenance of social status-signaling badges : experimental manipulations in lizards / Martin J. Whiting, Kenneth A. Nagy and Philip W. Bateman. Ecological and social contexts for the evolution of alternative mating strategies / Kelly R. Zamudio and Barry Sinervo. Social behavior and antipredatory defense in lizards / William E. Cooper, Jr. -- Variation among populations. Introduction / Gordon H. Orians.
