Download Free Variation In Spectral Reflectance Of White Feathers Book in PDF and EPUB Free Download. You can read online Variation In Spectral Reflectance Of White Feathers and write the review.

Advances in the Study of Behavior, Volume 29 continues to serve scientists across a wide spectrum of disciplines. Focusing on new theories and research developments with respect to behavioral ecology, evolutionary biology, and comparative psychology, these volumes foster cooperation and communications in these dense fields. The aim of Advances in the Study of Behavior remains as it has been since the series began: to serve the increasing number of scientists who are engaged in the study of animal behavior by presenting their theoretical ideas and research to their colleagues and to those in neighboring fields. We hope that the series will continue its "contribution to the development of the field," as its intended role was phrased in the Preface to the first volume in 1965. Since that time, traditional areas of animal behavior have achieved new vigor by the links they have formed with related fields and by the closer relationship that now exists between those studying animal and human subjects.
This is the first book to summarize the methods, conceptual issues and results of studies using the interpretation of feather growth rates as an index of nutritional condition in birds. The author has coined the term ptilochronology (literally, 'the study of feather time') to describe this technique, which relies on the fact that as a feather grows it produces visible growth bars. Both the technique and its conceptual foundations have been applied worldwide to numerous studies of avian evolution, ecology, and conservation biology. The author reviews this work, chronicles the various criticisms that have been made, and describes how these have influenced the development of ptilochronology. He goes on to suggest experimental methodologies and analytical techniques to safeguard against invalid results. A final chapter summarises this new technique's contribution to avian biology, and suggests potential applications and a future research agenda. An appendix details specific measurements and describes the methodology associated with ptilochronology. Ptilochronology provides a practical resource as well as a conceptual understanding of how this technique can be used to address important questions in avian biology. It will be of relevance and use to professional avian biologists and ornithologists as well as to graduate students of avian behavioural ecology, evolution and conservation.
Birds have evolved diverse plumage through sophisticated morphological modifications. The interaction of light with these modifications alters the reflectance from feathers, producing complex and directionally-variable visual signals. I hypothesize that structural modifications of the feather produce anisotropic reflectance, the direction of which is determined by the orientation of the structure of the vane. Variation in reflectance originates from the interplay of light with two classes of feather structure: its surface and subsurface volume. Different structural scales within the two structural classes influence light scattering within the UV-visible spectrum. The overall shape and surface of the feather vane (the macro-scale) and of its component members (the milli-scale) scatter light according to principles of geometric optics. Subsurface nano-scale structure in many feathers generate socalled "structural coloration," which is a purely physical optics phenomenon and can differ drastically from ordinary coloration mechanisms such as pigmentation. Iridescence, from which many feathers derive their vivid, eye-catching changeable color, is one type of structural color that varies as a function of viewing angle. This thesis presents investigations into a previously understudied aspect of avian visual signaling: directional reflectance and its relationship to milli-scale structure. Having observed that the stratified nano-scale morphology of structurallycolored plumage contours the milli-scale cortex of the vane, I determined that measurements of the milli-scale could be substituted for a more complex study of directional reflectance from the nano-scale. I thereby hypothesize that the direction of the reflectance from a vaned feather can be predicted from the orientation of its milli-scale morphology-its barbs and barbules. In collaboration with my colleagues at Cornell University, I developed non-destructive tools and methods to investigate the signaling potential of the feather. I correlate measurements of directional light scattering to the milli-scale morphology of select samples of structurally-colored bird plumage. The results of these analyses lead to a more thorough understanding of the relationships between directional reflectance and the structure of the feather itself. Having found the reflectance to be anisotropic, I demonstrate that the change in the direction of the reflectance over the surface of the vane can in fact be predicted from the orientation of the different branches of the barb. The improved understanding of the variation in directional reflectance over the surface of the feather, a phenotypic component, should allow for better comprehension of avian behavior, evolution of morphological adaptations, and the synthesis of more accurate predictive models.
Prior to publication the study of animal coloration was plagued by fanciful speculations, post hoc explanations and untestable hypotheses. This title, originally published in 1979, draws together widely scattered research into the coloration of animals; formulates predictive hypotheses to account for color; documents the accuracy of many of these hypotheses; and suggests directions for future research. The book grew out of a symposium, The Behavioral Significance of Color at the 1977 meeting of the Animal Behavior Society, and presents evidence concerning patterns of coloration and their influence on animal behaviour and interaction Physical principles of radiation are discussed in Chapter 1, followed, in subsequent chapters, by an examination of the physiological functions of animal coloration (e.g. thermoregulation, hydroregulation, abrasion-resistance, extraretinal photoreception). Treatment of coloration that affects the animal’s visibility to other animals opens with a masterful overview of theories of color vision and its occurrence throughout the animal kingdom. Chapter 6 explores the role of color vision and fruit color in the selection of food by wild primates with comments on the coevolution of fruiting trees and their primate customers. Dr Jack P. Hailman addresses the elusive concept of conspicuousness. He summarizes a strategy for calculating conspicuous coloration based on measurements in natural habitats. Experiments, naturalistic observations and anecdotes of optical communication are exceedingly numerous. Chapters 8 and 9 review these data and suggest general principles of inter- and intraspecific optical communication. Each chapter is enhanced by the critical evaluations of Drs. C. Richard Tracy and W. J. Hamilton III. In closing, the editor discusses coloration as it affects an animal’s own vision (e.g., black eyelines to reduce glare). Most significantly the book emphasizes the need for a balanced, scientifically rigorous approach to the question of evolution of animal coloration. It is an important source for anyone contemplating or currently involved in research in this field of investigation.
A comprehensive monograph of the beautiful Snowy Owl, famed for its elegant, all-white plumage. The Snowy Owl needs little introduction. This massive white owl breeds throughout the Arctic, wherever there are voles or lemmings to hunt, from Scandinavia through northern Russia to Canada and Greenland. Southerly movements in winter see North American birds travel as far south as the northern United States, while infrequent vagrants on the Shetlands and other northern isles are a magnet for birders. The Snowy Owl gives this popular bird the full Poyser treatment, with sections on morphology, distribution, palaeontology and evolution, habitat, breeding, diet, population dynamics, movements, interspecific relationships and conservation, supported by some fabulous photography. The award-winning author team also had access to Russian research literature, which is generally out of reach for Western scientists.
The Extended Specimen highlights the research potential for ornithological specimens, and is meant to encourage ornithologists poised to initiate a renaissance in collections-based ornithological research. Contributors illustrate how collections and specimens are used in novel ways by adopting emerging new technologies and analytical techniques. Case studies use museum specimens and emerging and non-traditional types of specimens, which are developing new methods for making biological collections more accessible and "usable" for ornithological researchers. Published in collaboration with and on behalf of The American Ornithological Society, this volume in the highly-regarded Studies in Avian Biology series documents the power of ornithological collections to address key research questions of global importance.