Avian Ecology and Conservation in an Urbanizing World. , , and , editors . 2001 . Kluwer Academic Publishers , Dordrecht, The Netherlands . 585 pp. $159.95. ISBN 07923-7458-4 .
Urbanization is a word used to identify the growth of cities and towns and the development of the surrounding landscape by human settlement. It is a process that has been occurring in all developed and many developing nations throughout the world. The rate of urbanization has increased in the last few decades to the point where it is of major concern to conservation biologists. The process has been so pervasive in North America that many refer to it as sprawl, a term that some do not like because of its negative connotations. Regardless of individual viewpoints on “progress,” urbanization is unquestionably a force to be reckoned with and understood.
Recently and increasingly, urban and suburban environments are being recognized as ecosystems in and of themselves, or as important parts of larger regional ecosystems. This changing view has important implications not only for ecologists but also for conservationists, policymakers, and human society in general. Ecological understanding and conservation issues are no longer relegated to national forests, national parks, wildlife refuges, or wilderness areas; they are intertwined in the increasingly prevalent human environment.
Marzluff et al. have produced an edited volume that takes on the complex processes involved in human development of the landscape and focuses on one taxonomic group, birds, within the realm of biodiversity. A great deal of ecological work has been done on birds, and we know quite a bit of the population ecology, community dynamics, and habitat relationships of this diverse and mobile group. Therefore, it is an appropriate and worthwhile endeavor to focus on the impact of urbanization on avian species and communities. In many ways, this book represents a merging of a new facet of ecology, urban ecology, with an old and venerated one, ornithology.
The editors state several objectives for the book with regard to how birds respond to human settlement, including a review of current knowledge. They also suggest ways of standardizing approaches for study; investigate connections between urbanization and individual birds, bird populations, and bird communities; investigate policy, conservation, and management implications; and suggest research needs and directions.
The book has 27 chapters grouped into five sections. In section 1, an “Introduction to the Study of Birds in Urban Environments” ( seven chapters ), the authors provide historical and world perspectives on the effects of urbanization on birds, the response of bird populations to development, and approaches to the study of birds in urban environments, such as quantifying urban gradients and applying multi-scale analyses in avian habitat-selection studies. It is a fairly comprehensive section that will be of interest to anyone concerned about urbanization, whether or not the focus is birds. Important contributions include a discussion for standardizing and quantifying terminology such as urban, suburban, rural, and exurban. Chapter 3 by Richard F. Johnston is a particularly fascinating account of “synanthropic” birds. Johnston defines biological synanthropy as human-mediated symbiosis and discusses the life-history strategies of such common birds as House Sparrows ( Passer domesticus), Rock Doves ( Columba livia ), and other species that show varying degrees of synanthropy. One message is that some species will be able to exploit rapidly changing environments, and there is as much to learn from these species as there is from the ones threatened with local extinction.
Section 2, “Processes Affecting Birds in Urban Environments” ( seven chapters ), addresses population and community responses to some specific processes that are not unique to urban environments but that are important driving forces in the complexities of urbanization. In this section, the authors discuss interactions of birds with non-native plants, nest predation, and bird tolerance to human disturbance. Several of the chapters make these points in a case-study approach, such as the effects of urban sprawl and juniper encroachment on the abundance of wintering birds in Oklahoma ( chapter 10 ) and the relative importance of anthropogenic sources ( e.g., lawns ) and natural sources of food for European Starlings ( Sturnus vulgaris ) in France ( chapter 13 ).
Sections 3 ( seven chapters ) and 4 ( five chapters ) present information on bird populations and communities, respectively, in urban environments. Among the species discussed are Western Gulls ( Larus occidentalis ), American Crows ( Corvus brachyrhynchos), Florida Scrub-Jays ( Aphelocoma coerulescens ), macaws ( Ara spp. ), and waterbirds ( grebes, loons, waterfowl, terns, gulls ). Case studies of bird communities come from St. Louis, Chicago, southwestern Ohio, and Toronto. The chapter on western gulls ( chapter 15 ) by Raymond Pierotti and Cynthia Annett summarizes 22 years of data on reproduction and diet in different colonies with varying amounts of urban influence. Pierotti and Annett point out that the existing paradigm is that gulls depend heavily on human refuse for sustenance, yet gulls existed for 40–50 million years before humans, an important perspective for all ecological studies. Their findings suggest that human refuse is nutritionally inferior to natural foods for chick development. In the lead chapter of section 4 ( chapter 22 ), Robert Blair addresses the concern of an increasingly homogenized biota as the presence of humans expands across the globe.
The final section, section 5, contains one chapter by two of the editors ( Bowman & Marzluff ). They attempt to integrate and synthesize interest in avian ecology with urban ecology. The authors recommend approaches to studying birds in urbanized environments, including developing appropriate metrics, measuring impacts on abiotic components of the urban ecosystem, and employing experimental ( manipulative ) approaches in research design.
Avian Ecology focuses on the processes and patterns of urbanization that affect bird populations and communities. It may be more of a collection of review and research papers than a comprehensive overview of the topic of urbanization and avian ecology. Like most edited works, the book struggles a bit to maintain a natural, progressive flow from one chapter or topic to the next. This, however, is more of an artifact of multiple authors, and it is not one editors can always overcome. Nevertheless, the authors present a lot of information and many thought-provoking ideas and insights. The book focuses on ecology; missing is any discussion of the role that human attitudes, perceptions, and values play in the conservation of birds and communities, as the authors of the synthesis chapter recognize. Likewise, critics could complain that the book overlooks the rest of biodiversity and that it perpetuates a continued bias toward birds. However, the in-depth look at birds taken by the contributors to Avian Ecology does not preclude similar types of investigations of other forms of life, or even more holistic approaches. For those who see the need to expand our understanding of the urban environment, Avian Ecology can help lead the way.
The book has a few unfortunate typographical errors, but probably the only serious drawback is the price. At U.S.$160, it is likely out of the reach of many interested potential buyers other than universities and libraries. It is worth trying to save up the cash or borrow a copy, however. The book contains a wealth of information, citations, and thought, and will likely serve as a building block in the foundation of our attempts to understand our impact on biodiversity and the environment in the places where most of us live and work.