Search results for: cowbirds-and-other-brood-parasites

Cowbirds and Other Brood Parasites

Author : Catherine P. Ortega
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The Brown-headed Cowbird is known to use the nests of more than 200 other bird species, and cowbirds in general are believed to play a role in the decline of some migratory songbird populations. These brood parasites—birds that lay their eggs in the nests of others—have long flourished in North America. In this timely book, Catherine Ortega summarizes and synthesizes a wealth of information on cowbirds from around the world that has appeared since the publication of Herbert Friedmann's classic 1929 monograph on these birds. Most of this information has appeared in the last quarter-century and reflects advances in our understanding of how brood parasitism influences, and is influenced by, host species. Ortega shows that in order to manage cowbirds without further damaging delicate balances in host-parasite relationships, it is necessary to understand such factors as behavior, reproduction, population dynamics, and response to landscape patterns. She examines and explains the origin, evolution, and costs of brood parasitism, and she discusses the philosophical and ecological considerations regarding the management of cowbirds—a controversial issue because of their perceived influence on threatened and endangered birds. Because brood parasitism has evolved independently in various bird families, information on this adaptive strategy is of great ecological interest and considerable value to wildlife management. Cowbirds and Other Brood Parasites is an important reference on these creatures that enhances our understanding of both their behavior and their part in the natural world.

Cuckoos Cowbirds and Other Cheats

Author : Nick Davies
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In this fascinating new book, Nick Davies describes the natural histories of these brood parasites and examines many of the exciting questions they raise about the evolution of cheating and the arms race between parasites and their prey. Brood parasites fill their armory with adaptations including exquisite egg mimicry, rapid laying, ejection of host eggs, murder of host young, chick mimicry and manipulative begging behavior: ploys shown by recent research to have evolved in response to host defense behavior or through competition among the parasites themselves. While many host species appear defenseless, accepting parasite eggs quite unlike their own, many are more discriminating against odd-looking eggs and some have evolved the ability to discriminate against odd-looking chicks as well. How is this arms race conducted? Will defenseless hosts develop defenses in time, or are there constraints which limit the evolution and perfection of host defenses? And why are so few species obliged only to lay eggs in host nests? Have host defenses limited the success of brood parasitism, or is it in fact much more common than we suspect, but occurring mainly when birds parasitize the nest of their own kind? All of these puzzles are examined in descriptions of the natural history of each of the groups of parasites in turn. Here is a book with wide appeal, both to amateur naturalists fascinated by this most singular and macabre of behaviors and by ornithologists and ecologists interested in the evolution of ecology and behavior. The story takes us from the classic field work earlier this century by pioneer ornithologists such as Edgar Chance, Stuart Baker, Herbert Friedmann and others, through to the recent experimental field work and molecular techniques of today's leading scientists. We visit brood parasites in Europe, Asia, Japan, Africa, Australasia, and North and South America, to look at some of the worlds most interesting birds and some of biology's most interesting questions, many of which still beg answers from ornithologists in the future. Brilliant illustrations by David Quinn illuminate the species discussed, showing many behaviors never before illustrated and conveying the thrill of watching these astonishing birds in the wild.

The Avian Brood Parasites

Author : Paul A. Johnsgard
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The evolutionary, ecological and behavioral questions posed by obligate brood parasites are among the most intriguing of all contemporary ornithological topics. Avian brood parasites lay their eggs in the nests of other birds and may be a major contributing factor driving several species of songbirds to near extinction. As one of the first books to present a comprehensive overview of this fascinating phenomenon, this work discusses the comparative biology and co-evolutionary adaptations exhibited by the five families of birds that engage in such behavior. Several chapters dealing with the comparative biology of both intraspecific and interspecific brood parasites, are followed by individual accounts of all known species--nearly 100 altogether, primarily cowbirds and cuckoos. Some of the more remarkable behavioral and structural adaptations of these birds include egg mimicry, juvenile mimicry, elimination by starvation or actual attack of other nestlings or host eggs, and even the learning and partial mimicry of host song traits. An extended glossary, a list of Latin names, 400 literature citations and range maps of all parasitic species discussed are also included. Detailed line drawings by the author enhance this synthesis of biological and ecological information.

Cuckoos Cowbirds and Other Cheats

Author : Nicholas B. Davies
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"In this fascinating new book, Nick Davies describes the natural histories of these brood parasites and examines many of the exciting questions they raise about the evolution of cheating and the arms race between parasites and their prey. Brood parasites fill their armory with adaptations including exquisite egg mimicry, rapid laying, ejection of host eggs, murder of host young, chick mimicry and manipulative begging behavior: ploys shown by recent research to have evolved in response to host defense behavior or through competition among the parasites themselves. While many host species appear defenseless, accepting parasite eggs quite unlike their own, many are more discriminating against odd-looking eggs and some have evolved the ability to discriminate against odd-looking chicks as well. How is this arms race conducted? Will defenseless hosts develop defenses in time, or are there constraints which limit the evolution and perfection of host defenses? And why are so few species obliged only to lay eggs in host nests? Have host defenses limited the success of brood parasitism, or is it in fact much more common than we suspect, but occurring mainly when birds parasitize the nest of their own kind? All of these puzzles are examined in descriptions of the natural history of each of the groups of parasites in turn. Here is a book with wide appeal, both to amateur naturalists fascinated by this most singular and macabre of behaviors and by ornithologists and ecologists interested in the evolution of ecology and behavior. The story takes us from the classic field work earlier this century by pioneer ornithologists such as Edgar Chance, Stuart Baker, Herbert Friedmann and others, through to the recent experimental field work and molecular techniques of today's leading scientists. We visit brood parasites in Europe, Asia, Japan, Africa, Australasia, and North and South America, to look at some of the worlds most interesting birds and some of biology's most interesting questions, many of which still beg answers from ornithologists in the future. Brilliant illustrations by David Quinn illuminate the species discussed, showing many behaviors never before illustrated and conveying the thrill of watching these astonishing birds in the wild."--Bloomsbury Publishing.

Cognitive Challenges for Brood parasitic Cowbirds

Author : Mark Erno Hauber
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Collectively, these studies should guide future experimental research efforts on the species, mate, kin, and host recognition systems of other parasitic species and those taxa in general where young develop in early social environments that do not predictably include individuals of their own species. The results are also informative about previously poorly understood aspects of the natural history of obligate brood parasitic birds.

Avian Brood Parasitism

Author : Manuel Soler
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Brood parasitism has become one of the most flourishing areas of research in evolutionary ecology and one of the best model systems for investigating coevolution. This subject has undergone remarkable advances during the last two decades, but has not been covered by any book in the 21st century. This book offers a comprehensive and up-to-date overview of the fascinating field of avian brood parasitism. The topics covered include conspecific brood parasitism; evolution and phylogenetic history of avian brood parasites; parasitic behaviour used by brood parasites; adaptations and counter-adaptations of brood parasites and their hosts at every stage of the breeding cycle (before laying, egg, chick and fledgling stages); factors affecting the evolution of host defences and parasitic attacks; the role of phenotypic plasticity in host defences; mechanisms driving egg recognition and rejection; evolution of nest sharing or nest killing by brood parasite chicks; begging behaviour in parasitized nests and food delivery by host adults; and recognition of conspecifics by juvenile brood parasites. This volume provides a comprehensive reference resource for readers and researchers with an interest in birds, behaviour and evolution, as well as a source of hypotheses and predictions for future investigations into this dynamic subject.

Anti brood Parasite Defenses and Nest site Selection by Forest edge Songbirds in Central Missouri

Author : Dirk E. Burhans
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Brood parasites such as cowbirds exert strong selective forces upon hosts to coevolve defenses to counter the costs imposed by raising parasitic young. These defenses may occur on the behavioral level or may be related to the way in which hosts select their nest sites. I examined the way in which nest-site selection and host defenses are related to brood parasitism by the Brown-headed Cowbird (Molothrus ater) and nest predation in central Missouri for Field Sparrow (Spizella pusilla) and Indigo Bunting (Passerina cyanea). By comparing the similarities and differences in nest-site selection and parasitism dynamics between Field Sparrows and Indigo Buntings I hope to shed light on the patterns and processes involved in nest-site selection and anti-brood parasite defenses. Indigo Buntings and Field Sparrows were parasitized at very different frequencies despite their similarities in nesting biology. Parasitism frequency in both species was best explained by average side nest concealment except for Indigo Buntings nesting under forest canopy. Buntings nesting under forest canopy were more heavily parasitized, indicating that habitat-scale considerations may override microhabitat features in explaining parasitism. Nest predation and daily nest survival in Field Sparrows and Indigo Buntings showed opposing patterns seasonally and by nesting stage. Microhabitat variables explained predation frequencies in Field Sparrows, but not Indigo Buntings. Aggressive defense at the nest did not explain differences in parasitism frequency between Indigo Buntings and Field Sparrows based on experiments with models. Field Sparrows frequently deserted cowbird-parasitized nests, and morning nest arrival observations suggested that they often encounter cowbirds parasitizing their nests. Experiments indicated that Field Sparrows may not recognize cowbirds as brood parasites, but as predators; however, nest desertion may be a response that is appropriate for both parasitism and nest predation, because predators may return to take the entire nest contents.

Ecological and Behavioral Factors Influencing Host Selection by the Brown headed Cowbird Molothrus Ater a Generalist Avian Brood Parasite

Author : Thomas Bennett Ford
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Brood Parasitism by Shiny Cowbirds

Author : Rosalyn Suzanne Gloag
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Host Relations of the Parasitic Cowbirds

Author : Herbert Friedmann
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Cowbirds are an ideal group in which to study the biology of brood parasitism; within the six included species there are displayed all stages of the development of this mode of reproduction ranging from that of the non-parasitic bay-wing through those of the completely parasitic screaming, shiny, brown-headed, bronzed, and giant cowbirds. The present report deals only with their host relationships, as this is the aspect of their biology in which our knowledge has shown the greatest increase since the author's discussion was published in 1929.

Host Community Dynamics and Reproductive Biology of a Generalist Avian Brood Parasite the Brown headed Cowbird

Author : David R. Curson
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Grazing Impact on Brood Parasitism

Author : Anthony James Locatelli
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Anthropogenic land use changes can have tremendous direct and indirect effects on biota. A prevalent land use change in Texas is conversion of land to grazing. Grazing facilitates foraging opportunities for brown-headed cowbirds (Molothrus ater), a brood parasite. Cowbirds can reduce productivity of their hosts, causing some host species to decline in abundance. Thus, grazing indirectly influences productivity of some songbirds. The black-capped vireo (Vireo atricapilla) is an endangered songbird with most of its breeding range occurring in areas of livestock and other ungulate grazing. A contributing factor to its endangered status is brown-headed cowbird parasitism. I monitored 382 black-capped vireo nests from 2012-2013 in Real, Kerr, Bandera and Edwards counties, Texas and described parasitism. I investigated how grazing system related to parasitism; I defined grazed systems by the presence of enclosed ungulates and wild ungulate only systems by the absence of enclosed ungulates. I also examined how grazing intensity (represented by distance from nest to nearest ungulate water source), nest concealment, and grazing in the landscape (represented by proportion of grassland within 3 km of a nest), related to parasitism. Overall parasitism was 30% (n = 166) in 2012 and 31% (n = 216) in 2013, moderate compared to other research, but above a proposed threshold of concern. Grazing system and grazing in the landscape interacted in predicting probability of parasitism. Grazing in the landscape was not important in predicting brood parasitism in wild ungulate only grazing systems, but was important in predicting brood parasitism in grazed systems. In grazed systems, there was low probability of brood parasitism with low grazing in the landscape and high probability of parasitism with high grazing in the landscape. Nest concealment and grazing intensity were not good predictors of brood parasitism. Land managers could use this information to prioritize cowbird management or preservation efforts. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/152702

Growing Up Prairie

Author : Sarah Winnicki
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Animals develop at different rates and require differing amounts of parental investment, yet the drivers of both inter- and intraspecific variation in growth are often unclear. In altricial birds, both food delivery by parents and nest predation risk are known to influence developmental strategies, but until now, it has been unclear how brood parasitism might influence host development. I studied interactions between brood parasitic Brown-headed Cowbirds (Molothrus ater) and three grassland-obligate songbirds at the Konza Prairie in Northeast Kansas. My three focal host species ranged in size from ~40% to 270% of cowbirds' mass: large Eastern Meadowlarks (Sturnella magna), medium-sized Dickcissels (Spiza americana), and small Grasshopper Sparrows (Ammodramus savannarum). We hypothesized that brood parasitism by cowbirds would influence inter- and intraspecific development variation (1) directly by exacerbating costly sibling competition and/or (2) indirectly by interacting with other environmental drivers like predation risk and food availability. Additionally, we hypothesized that (3) host species, nest-specific food provisioning rate, and spatial variation in predation risk would influence intra-specific cowbird nestling growth. I located and monitored 148 nestling-stage nests over two years, and measured the growth of 316 host nestlings' and 54 cowbird nestlings' tarsi, wings, mass, bills, and feathers every two days to quantify overall growth and the allometric scaling of structures associated with nestling competition and post-fledging mobility. Variation in host nestling development exhibited species-specific responses to cowbird parasitism; meadowlarks left the nest earlier than conspecifics in unparasitized nests, Dickcissel nestlings grew more slowly, and Grasshopper Sparrow nestlings were not directly affected by the presence of brood parasites. Brood parasitism was also associated with key drivers of nestling development including nest predation risk and provisioning rate. However, considerable variation in host growth appeared to be shaped by individual variation in parental care. Cowbird nestling mass gain and the allometric scaling of body parts associated with nestling competition varied among host species, and was associated with provisioning rate and brood size. Overall these results demonstrate that inter- and intraspecific variation in growth and development can be extremely high, even at a single site. Additionally, brood parasitism can have species- and nest-specific consequences attributable in part to individual parental behavior. These results provide insight into the relationship between a declining guild of grassland songbird host species and the native brood parasites with which they have interacted for millennia, and helps interpret host-parasite interactions in novel contexts.

Behavioral Ecology of Juvenile Brown headed Cowbirds Implications for the Evolution and Maintenance of Avian Brood Parasitism

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Defense of American Robins Turdus Migratorius Against Avian Brood Parasitism in Areas of Sympatry and Allopatry with the Brood Parasitic Brown headed Cowbird Molothrus Ater

Author : Lisa A. Cooper
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Bird Love

Author : Wenfei Tong
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Exploring the sex life of birds and their wide range of mating and parenting habits, Bird Love gives you a detailed insight into bird family life. Discover the amazing array of courtship techniques employed by birds around the world, such as ospreys bringing gifts of food in exchange for sex, male skylarks performing aerial acrobatics to impress females, or long-tailed widowbirds showing off their tails to advertise the quality of their genes. Finding a prime nesting location is paramount, and the skills to build a safe nest in which to raise young can be just as attractive as having extravagant plumage. Security matters too - even to the extent of female hornbills who seal themselves in to their tree hollow nests, relying on their mates to deliver food through a narrow slit. But it’s not all about males seeking to impress or dominate females: sex roles can be reversed, and the book includes examples such as the black coucal, whose females leave the males to perform all childcare duties. The limited availability of nest holes for the eclectus parrots of Melanesia means that females fight each other to secure a home, and the winner may have up to seven mates. Varying levels of parental care are revealed, from both parents having to provide constant care to allowing an insurance chick to die to ensure at least one survives. And either sex can desert the nest in search of further matings to secure another clutch of chicks and the continuation of their family line. Brood parasitism, where birds such as cuckoos and cowbirds lay their eggs in other birds’ nests, takes absentee parenting to the extreme and the book explores how these species have evolved to delegate all parental care. Alongside, it also shows how host species have cleverly developed a wide range of tactics to defend their nests and their own families. The essential insight to bird family life, Bird Love is richly illustrated with stunning colour photographs, and regular Backyard Bird boxes in each chapter showcase familiar species from around the world.

Impact of Brown headed Cowbird Brood Parasitism on Red winged Blackbirds and Factors Influencing Patterns of Parasitism

Author : Ethan D. Clotfelter
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Burny The Carefree Cowbird

Author : Michael D. Trout
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Burny the Cowbird shows his cowbird friends an easier life. Cowbirds by nature are brood parasites, meaning that they use other birds to raise their young. This is just one of the many tricks that Burny uses to show how socialism gives the cowbirds power over other animals and saves them from hard work. But, at what cost is socialism instituted? Does socialism actually create Equality of Outcome? Or, do the cowbirds discover something deeply sinister about Burny's plan? Read and share with family and friends the story of Burny the Carefree Cowbird to unveil a truly parabolic story of socialism.

Parasitic Birds and Their Hosts

Author : Stephen I. Rothstein
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This book is the first to present a comprehensive overview of parasitic birds and their hosts. Although the phenomenon has attracted the interest of naturalists and evolutionists since Darwin, only recently have researchers applied modern evolutionary theory and experimental methods to study the various adaptations related to brood parasitism. The work in this field is accelerating rapidly, and this volume collects work from the individuals and research groups around the world who have been responsible for nearly every major study in the last ten years. The papers present valuable summaries along with substantial new research, and the volume concludes with a review of important unsolved questions. The book is an invaluable resource on this fascinating topic, covering the remarkable sequences of adaptations and counter-adaptations, along with the perhaps even more remarkable cases where adaptations seem to be lacking.

Cuckoos Cowbirds and Other Cheats

Author : Nick Davies
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In this fascinating new book, Nick Davies describes the natural histories of these brood parasites and examines many of the exciting questions they raise about the evolution of cheating and the arms race between parasites and their prey. Brood parasites fill their armory with adaptations including exquisite egg mimicry, rapid laying, ejection of host eggs, murder of host young, chick mimicry and manipulative begging behavior: ploys shown by recent research to have evolved in response to host defense behavior or through competition among the parasites themselves. While many host species appear defenseless, accepting parasite eggs quite unlike their own, many are more discriminating against odd-looking eggs and some have evolved the ability to discriminate against odd-looking chicks as well. How is this arms race conducted? Will defenseless hosts develop defenses in time, or are there constraints which limit the evolution and perfection of host defenses? And why are so few species obliged only to lay eggs in host nests? Have host defenses limited the success of brood parasitism, or is it in fact much more common than we suspect, but occurring mainly when birds parasitize the nest of their own kind? All of these puzzles are examined in descriptions of the natural history of each of the groups of parasites in turn. Here is a book with wide appeal, both to amateur naturalists fascinated by this most singular and macabre of behaviors and by ornithologists and ecologists interested in the evolution of ecology and behavior. The story takes us from the classic field work earlier this century by pioneer ornithologists such as Edgar Chance, Stuart Baker, Herbert Friedmann and others, through to the recent experimental field work and molecular techniques of today's leading scientists. We visit brood parasites in Europe, Asia, Japan, Africa, Australasia, and North and South America, to look at some of the worlds most interesting birds and some of biology's most interesting questions, many of which still beg answers from ornithologists in the future. Brilliant illustrations by David Quinn illuminate the species discussed, showing many behaviors never before illustrated and conveying the thrill of watching these astonishing birds in the wild.