Birds in Urban Ecosystems: Population Dynamics, Community Structure, Biodiversity, and Conservation

With the global high rate of urbanization and the rapid loss of wild habitat land, cities are now viewed as challenging ecosystems for sustaining biotic communities and rich diversity. During the 2000s research on urban bird populations and communities focused on global patterns, as well as processes and mechanisms that lead to the two globally recognized patterns: increased overall population densities and decrease in species diversity compared with wildlands. Birds adapt to the urban ecosystem both physiologically (changes in stress hormones), and behaviorally (e.g., changes in foraging behavior, extending the breeding season). The increase in population density is related to the increase in food abundance, and probably to the reduction in predation pressure. The loss of diversity is related to loss of habitat, the high human density, and negative interactions with synanthropic species. Recognizing that the urban habitat will continue to grow, efforts to turn the city into a more friendly habitat for a variety of bird species should focus not only on habitat and vegetation structure, but also on niche opening for subordinate species, by excluding locally aggressive, synanthropic species. Although the study of urban birds has a fairly long history, urban ecosystems have been largely ignored throughout many decades of ecological research (Miller and Hobbs, 2002; Collins et al., 2000). Since the early 1990s, a different view emerged, accepting urban settings as ecosystems that are structured and function like other natural ecosystems (McDonnell and Pickett, 1990; Rebele, 1994; Grimm et al., 2000; McKinney, 2002; Miller and Hobbs, 2002). This theoretical view represents an emerging realization that by now, most of the world’s land is managed and dominated by humans (approximately 50% of the human population lives in cities). Wildlands are continuously converted to agricultural fields E. Shochat, Global Inst. of Sustainability, Arizona State University, Box 875411, Tempe, AZ 85287 (eyal. [email protected]); S. Lerman, Dep. of Organismic and Evolutionary Biology, University of Massachusetts, 319 Morrill Science Ctr. South, 611 N. Pleasant St., Amherst, MA 01003 ([email protected]. edu); E. Fernández-Juricic, Dep. of Biological Sciences, Purdue University, G-420 Lily Hall, 915 W. State St., West Lafayette, IN 47907 ([email protected]). doi:10.2134/agronmonogr55.c4 Copyright © 2010. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, 5585 Guilford Road, Madison, WI 53711, USA. Agronomy Monograph 55. Urban Ecosystem Ecology. J. Aitkenhead-Peterson and A. Volder (ed.)