D.M. Power – författare

This edited series has three principal goals. The first is to provide information in a relatively concise way for researchers needing an over­ view of specific disciplines. The second is to provide an update on specific schools of thought, bringing together ideas from colleagues whose works often appear in a variety of journals. And the third is to stimulate and suggest directions for new research. Volume 6 continues the tradition established by the previous editor and editorial board in providing new information, updating our understanding of specific dis­ ciplines, and stimulating new research. In the first chapter, Randall Breitwisch examines mortality patterns and sex ratios in monogamous birds. He argues that there are many more components to measuring parental investment than are often re­ alized; our knowledge is weak in several areas. Understanding the evo­ lution of mating systems depends on better distinguishing the different intensities of natural selection that operate on males and females. Greg­ ory Butcher and Sievert Rohwer develop a framework for assessing the role of colorfulness in birds. They propose several hypotheses to test and advocate evaluating more than one hypothesis at a time. Future work on the evolution of distinctive coloration and of sexual and age dimorphism must take these ideas into account.

Contributors to this volume offer new research on extinction processes in birds, nest predation, and song systems, and describes a graphical model that helps predict the reproductive consequences of time allocation between the competing demands of guarding young birds and foraging for food. Current Ornithology is the only English-language publication currently devoted exclusively to extensive reviews and synthesis of topics pertaining to all aspects of the biology of birds. Chapters fall under such diverse rubrics as ecology, evolution, behavior, phylogeny, behavioral ecology, anatomy and physiology, and conservation biology. All authors are leading authorities on their subjects, and each chapter is refereed by experts in the topics covered. Although all chapters focus primarily on birds, some topics, such as the social cognition of birds as compared to primates (Volume 13), have significant application to disciplines outside of ornithology. Current Ornithology aims to provide an accessible, up-to-date, accurate source of data and to contribute to conceptual generalization and unification across the biological sciences.

In this volume I include chapters on continental population trends, orni­ thology's contribution to the habitat concept, social organization outside the breeding season, the role of predation in limiting numbers, and the evolution of prolonged incubation periods. Authors are based in Belgium, the United Kingdom, and the United States. Is there evidence for wholesale population declines in North Ameri­ can birds? Robert Askins says yes, with qualifications. Fragmentation of forest causes the population of many forest-interior species to decline, and loss of winter forest habitat in Mexico, Central America, and the Greater Antilles is potentially serious. Trends over the past 25 years are, however, difficult to discern. Grassland and shrubland specialists have likewise diminished over the past quarter century. Askins calls for management of regional landscapes to maintain habitat diversity. As for habitats, William Block and Leonard Brennan review the role of ornithology in developing the concept of "habitat." Their intention is to stimulate ornithologists to consider habitat as a unifying concept in con­ temporary ecology. They describe uses of the habitat concept in basic and experimental ecology. Recent advances in sociobiology stimulated deeper interest in social organization. Erik Matthysen has gathered a diversity of information on social organization outside the breeding season, both in migratory and in nonbreeding resident birds. He discusses populations that continue indi­ vidual associations outside the breeding season and site-related aggression (territoriality), and reviews a number of long-term benefits of these behaviors.

In Volume 12, eminent international ornithologists further elucidate endocrinological correlates of mating strategies and hormones and reproductive behavior; assess the value of the ''brood reduction hypothesis'' in explaining ''the paradox of hatching asynchrony''; and explore the validity and sensitivity of growth bands in feathers as an indication of nutritional condition and the use of feather banding in studying growth. Chapters are well supported with charts, maps, schematic diagrams, and photographs. Current Ornithology is the only English-language publication currently devoted exclusively to extensive reviews and synthesis of topics pertaining to all aspects of the biology of birds. Chapters fall under such diverse rubrics as ecology, evolution, behavior, phylogeny, behavioral ecology, anatomy and physiology, and conservation biology. All authors are leading authorities on their subjects, and each chapter is refereed by experts in the topics covered. Although all chapters focus primarily on birds, some topics, such as the social cognition of birds as compared to primates (Volume 13), have significant application to disciplines outside of ornithology. Current Ornithology aims to provide an accessible, up-to-date, accurate source of data and to contribute to conceptual generalization and unification across the biological sciences.

Detailing novel research methods, this compilation presents major advances in fundamental aspects of phylogeny, mating, parental care, the trophic structure of Raptor communities, demography, behavioral ecology, species diversity, and the evolution of avian ontogenies. The book also features the most extensive list of international references available on raptor diet and feeding behavior and nocturnality. Current Ornithology is the only English-language publication currently devoted exclusively to extensive reviews and synthesis of topics pertaining to all aspects of the biology of birds. Chapters fall under such diverse rubrics as ecology, evolution, behavior, phylogeny, behavioral ecology, anatomy and physiology, and conservation biology. All authors are leading authorities on their subjects, and each chapter is refereed by experts in the topics covered. Although all chapters focus primarily on birds, some topics, such as the social cognition of birds as compared to primates (Volume 13), have significant application to disciplines outside of ornithology. Current Ornithology aims to provide an accessible, up-to-date, accurate source of data and to contribute to conceptual generalization and unification across the biological sciences.

In this volume I include chapters on continental population trends, orni­ thology's contribution to the habitat concept, social organization outside the breeding season, the role of predation in limiting numbers, and the evolution of prolonged incubation periods. Authors are based in Belgium, the United Kingdom, and the United States. Is there evidence for wholesale population declines in North Ameri­ can birds? Robert Askins says yes, with qualifications. Fragmentation of forest causes the population of many forest-interior species to decline, and loss of winter forest habitat in Mexico, Central America, and the Greater Antilles is potentially serious. Trends over the past 25 years are, however, difficult to discern. Grassland and shrubland specialists have likewise diminished over the past quarter century. Askins calls for management of regional landscapes to maintain habitat diversity. As for habitats, William Block and Leonard Brennan review the role of ornithology in developing the concept of "habitat." Their intention is to stimulate ornithologists to consider habitat as a unifying concept in con­ temporary ecology. They describe uses of the habitat concept in basic and experimental ecology. Recent advances in sociobiology stimulated deeper interest in social organization. Erik Matthysen has gathered a diversity of information on social organization outside the breeding season, both in migratory and in nonbreeding resident birds. He discusses populations that continue indi­ vidual associations outside the breeding season and site-related aggression (territoriality), and reviews a number of long-term benefits of these behaviors.