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Fall Transient Period

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter focuses on the fall transient period in the avian migrant's annual cycle. The fall transient period begins with the end of the postbreeding period as migratory birds depart on fall ... More

This chapter focuses on the fall transient period in the avian migrant's annual cycle. The fall transient period begins with the end of the postbreeding period as migratory birds depart on fall migration. From an evolutionary perspective, this is the most critical portion of the annual cycle because it is difficult to understand how this first migrant gets back to its natal area after successful completion of breeding, and even more formidable to comprehend how its offspring complete such a journey. The chapter first considers the physiologic and associated behavioral changes that a migrant undergoes in preparation for, and during, its migratory journey. It then examines the environmental cues in control over the evolved physiologic and behavioral responses of migrants, the timing of departure within the fall transient period, and the timing of departure within the circadian period. It also discusses the bird's migratory flight and migration route, orientation and navigation, and stopover.Less

Prototype System for Tracking and Forecasting Highly Pathogenic H5N1 Avian Influenza Spread in North America

A. Townsend Peterson

in Emerging Avian Disease

The recent emergence of a highly pathogenic strain (H5N1) of avian influenza that affects both birds and humans has raised global concern about its spread. Given the rapid spread of the disease and ... More

The recent emergence of a highly pathogenic strain (H5N1) of avian influenza that affects both birds and humans has raised global concern about its spread. Given the rapid spread of the disease and the desire for proactive monitoring and preparedness, I present a prototype forecasting framework for H5N1 dispersal for when/ if it arrives in North America via migratory bird movements. The prototype summarizes movement patterns by six species of arctic-breeding Anseriformes and emphasizes the importance of spread along all coasts of North America, as well as along the lower Mississippi River. This forecasting system is applicable only to the extent that migratory birds are the principal mode of dispersal and spread of the disease. The H5N1 situation calls for considerable effort in (1) understanding details of bird migration globally, (2) sharing avian biodiversity data globally, and (3) exploring novel approaches to data analysis and interpretation.Less

Spring Transient Period

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter focuses on the avian migrant's spring transient period, which begins with departure from the wintering area and ends with arrival at the breeding area. The emphasis is on the ... More

This chapter focuses on the avian migrant's spring transient period, which begins with departure from the wintering area and ends with arrival at the breeding area. The emphasis is on the “reproduction” aspect of the fitness equation rather than the “survival” aspect. This shift in emphasis from survival to reproduction has far-reaching effects on migratory birds' adaptation for movement from nonbreeding to breeding areas. The chapter first considers the bird's preparation for spring departure and goes on to discuss the endogenous factors and distal cues governing the timing of spring departure. It then examines the timing of departure within the spring transient period and within the circadian period, along with the migrant's migratory flight and migration route. It also describes the avian migrants' orientation, navigation, and stopover in spring and concludes by analyzing the impact of climate change on bird migration.Less

the Latin American Turn Nature protection in the Western Hemisphere

in Nature's Ghosts: Confronting Extinction from the Age of Jefferson to the Age of Ecology

In 1920, the ornithologist Alexander Wetmore left Washington, D.C., for an extended ornithological reconnaissance of Argentina, Chile, Paraguay, and Uruguay. His trip came after the U.S. Senate had ... More

In 1920, the ornithologist Alexander Wetmore left Washington, D.C., for an extended ornithological reconnaissance of Argentina, Chile, Paraguay, and Uruguay. His trip came after the U.S. Senate had passed an unusual resolution calling for a treaty to protect North American birds that spent part of the year below the Rio Grande. A thirty-two-year-old assistant biologist with the Bureau of the Biological Survey, Wetmore was a logical choice not only to assess the current status of migratory birds in that region of the world but also to gage the prospects for an international agreement aimed at safeguarding them. Wetmore later became the foremost expert on Central and South American birds and one of the forces pushing the American Committee for International Wild Life Protection to become more involved with wildlife conservation in Latin America. The first inkling of the American Committee's turn toward Latin American conservation revolved around the Galápagos Islands, where high rates of endemism and vulnerability were evident. The American Committee recognized the importance of a more international approach to the problem of extinction.Less

Migratory Birds and Pathogen Movement

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter discusses the role of avian migrants in the movement and spread of pathogens, with particular emphasis on West Nile virus (WNV) and avian influenza. Migratory birds can serve as hosts ... More

This chapter discusses the role of avian migrants in the movement and spread of pathogens, with particular emphasis on West Nile virus (WNV) and avian influenza. Migratory birds can serve as hosts for many kinds of viral and bacterial pathogens. In particular, avian involvement in the epidemiology of both WNV and avian influenza has been well documented. Despite lack of conclusive data, a general consensus has been reached in the published literature that migratory birds were the principal agents responsible for the introduction and spread of WNV in the Western Hemisphere during the epidemic that began in August 1999 and for the introduction and movement of avian influenza subtype H5N1 across Eurasia and into Africa that began in 1996.Less

Connectivity and Conservation

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter discusses the relevance of avian migrant “connectivity” to conservation efforts. “Connectivity” refers to “the degree to which individuals of populations are geographically arranged ... More

This chapter discusses the relevance of avian migrant “connectivity” to conservation efforts. “Connectivity” refers to “the degree to which individuals of populations are geographically arranged among two or more periods of the annual cycle.” Recent technological developments such as satellite radio-tracking, light-level geolocators, stable isotope analysis, and DNA hybridization now make it possible to connect the various parts of the migrant annual cycle for at least some individuals of some species. This chapter focuses on the conservation of migratory birds in relation to three major areas: research, national and international conservation policy collaboration, and management. In particular, it examines three programs that have been extremely important in recent efforts to preserve migratory bird populations: species-specific migratory bird conservation, coffee and migratory bird conservation, and the U.S. Fish and Wildlife Service refuge systems and the Neotropical Migratory Bird Conservation Act.Less

Conclusion

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter summarizes the book's main points concerning the ecology, life history, and evolution of migratory birds. It first considers migration as a behavior used to exploit geographically ... More

This chapter summarizes the book's main points concerning the ecology, life history, and evolution of migratory birds. It first considers migration as a behavior used to exploit geographically separate environments that differ seasonally in their value for survival and reproduction. It then discusses the avian migrant's breeding period, postbreeding period, fall transient period, wintering period, and spring transient period. It also reviews the avian migrant's population ecology, evolution and biogeography, and its role in the movement and spread of pathogens such as West Nile virus (WNV) and avian influenza, along with the relevance of avian migrant “connectivity” to conservation. Finally, it reflects on the issue of migrant origins and migration as a life history strategy.Less

Wintering Period

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter examines the basic pattern of the avian migrant's wintering period as well as its principal variations. The “wintering period” is the nonbreeding portion of the life cycle in which the ... More

This chapter examines the basic pattern of the avian migrant's wintering period as well as its principal variations. The “wintering period” is the nonbreeding portion of the life cycle in which the migratory bird spends the majority of its time, and the “winter range” is the place where the majority of its population spends that period. For many species of migratory birds, this classification is straightforward, with a wintering period spent in northern South America that lasts from the end of October to the beginning of April. For some other species, the movement to the wintering ground is more complex, involving at least one prolonged stopover of 6–8 weeks in sub-Saharan savannah before continuation on to wintering grounds in trans-equatorial Africa. The chapter describes the bird's arrival at the wintering ground and the duration of migration and goes on to discuss sociality in terms of intraspecific interactions during the nonbreeding period. It also considers the factors responsible for nonbreeding distribution patterns of avian migrants, including climate and food resources.Less

Postbreeding Period

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter focuses on the postbreeding period in the avian migrant's annual cycle. It first discusses the five principal purposes for the postbreeding period: conduct of the prebasic molt; ... More

This chapter focuses on the postbreeding period in the avian migrant's annual cycle. It first discusses the five principal purposes for the postbreeding period: conduct of the prebasic molt; exploratory movements by juveniles to familiarize themselves with location of feeding and potential breeding areas; prospecting movements by adults anticipatory of the next breeding season; preparation for departure on fall migration; and optimization of feeding strategies to limit predation while engaged in other postbreeding activities. It then considers migratory birds' movements and habitat use during the postbreeding period, along with the duration of their postbreeding period. It also examines the timing and siting of the prebasic molt in relation to other major events in the migrants' life cycle.Less

Breeding Period

John H. Rappole

in The Avian Migrant: The Biology of Bird Migration

This chapter focuses on the breeding period in the avian migrant's annual cycle, from arrival on the breeding grounds to completion of reproductive activities. Arrival times naturally differ for ... More

This chapter focuses on the breeding period in the avian migrant's annual cycle, from arrival on the breeding grounds to completion of reproductive activities. Arrival times naturally differ for different kinds of migratory birds. In temperate eastern Europe, for example, long-term averages of first spring arrival dates for different species are spread out over almost three months, with short-distance migrants generally arriving back earlier and showing a much broader range of annual variation in arrival time than their long-distance counterparts. This chapter also discusses avian migrants' site fidelity and dispersal, selection of breeding habitat, and the interval between arrival and reproduction during the process of migration.Less

A Perilous Journey

Paul F. Steinberg

in Who Rules the Earth?: How Social Rules Shape Our Planet and Our Lives

For sheer splendor, few natural wonders can outperform the seasonal migration of birds across the planet. Each year about 100 billion birds traverse the ... More

For sheer splendor, few natural wonders can outperform the seasonal migration of birds across the planet. Each year about 100 billion birds traverse the globe in search of greener pastures during the winter and return to their mating grounds when temperatures warm. Record-holders like the Arctic Tern travel thousands of miles to reach their destination. But even the less athletic members of the avian family feel the urge. As winter approaches, groups of California mountain quail hobble along by foot 15 miles down to the safety of the valleys below, and make their way steadily back up the mountain slope come spring. On a planet dominated by human artifacts and controlled environments, birds remind us of the ancient things—cycles of nature stretching back well before the first humans walked the landscape. This is equally true of their morning song. If you stood at the North Pole with a microphone powerful enough to detect it, you would hear an enormous wave of music slowly circling the earth each day, as a chorus of millions of birds awaken, their song tracking the leading edge of sunlight moving westward around the earth’s perimeter. When we think of the study of the earth’s natural wonders, what comes to mind are images from the natural sciences—lab coats and test tubes, gloves and galoshes, fish nets and soil samples. And when we wish to learn more about our environment, we consult these same sources of expertise. Take birding guides, for example. If you visit the southeastern United States in the spring, you may be fortunate enough to catch a glimpse of an adorable little blue bird called the cerulean warbler, literally the “sky blue singer.” Consulting a trusted birding guide such as Peterson’s, you will learn certain things. The cerulean is 4½ inches in length. It has a thick pointed beak suited to its preferred diet of insects. It breeds in North America, where it builds cup-shaped nests high in the trees to hatch its chicks. Less

Tamarisk Management at Bosque Del Apache National Wildlife Refuge: A Resource Manager’s Perspective

Gina Dello Russo

in Tamarix: A Case Study of Ecological Change in the American West

This chapter describes tamarisk management at Bosque Del Apache National Wildlife Refuge, located on the Rio Grande in central New Mexico, from a resource manager's perspective. The Refuge was ... More

This chapter describes tamarisk management at Bosque Del Apache National Wildlife Refuge, located on the Rio Grande in central New Mexico, from a resource manager's perspective. The Refuge was established in 1937 as a wintering area for migratory birds, particularly the sandhill crane (Grus canadensis). To maintain habitat for the thousands of birds and other wildlife that depend on the Refuge, tamarisk had to be controlled and if possible eradicated from floodplain areas. The chapter begins with an overview of the Refuge's early experiences with tamarisk establishment and control during the years 1942–1992 before turning to its implementation of adaptive management techniques for larger-scale research projects from 1992 to 2000. It then considers the Refuge's successes with respect to establishment of native plants and the challenges it encountered, along with its focus on landscape level tamarisk control in 2000–2010. Finally, it discusses the Refuge's prospects and steps for tamarisk control and management in 2010 and beyond.Less