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Report: U.S. Sprawl Endangers Hundreds of Nation's Imperiled Species

The rapid consumption of land in the nation's fastest-growing large metropolitan areas could threaten the survival of nearly one out of every three imperiled species, according to the first study ever to quantify the impact of sprawling development on wildlife nationally. In at least three dozen rapidly-growing counties found mostly in the South and West, open space on non-federal lands is being lost so quickly that essential wildlife habitat will be mostly gone within the next two decades, unless development patterns are altered.

According to the report Endangered By Sprawl: How Runaway Development Threatens America's Wildlife, produced by the National Wildlife Federation, Smart Growth America, and NatureServe, the rapid conversion of once-natural areas and farmland into subdivisions, shopping centers, roads and parking lots has become a leading threat to America's native plants and animals.

"Runaway sprawl will deplete wildlife habitat in many metropolitan areas in the next two decades," said John Kostyack, National Wildlife Federation senior counsel and a co-author of the report. "As Endangered by Sprawl shows, consumption of these critical areas could bring an astonishing number of species up to, or even over, the brink of extinction. If we allow that to happen, both people and wildlife will suffer."

The report recommends ways to stem the tide of habitat loss by changing local land use patterns and improving state and federal natural resource and transportation policies. "As Congress prepares to debate the future of the Endangered Species Act, this study drives home the critical role that better planning must play in both protecting threatened wildlife and improving our cities and towns," said Don Chen, Executive Director of Smart Growth America. "To check runaway land consumption, we need to provide incentives for development in existing urban and suburban areas, build new development at higher densities, and set aside natural areas as off limits to new development."

Endangered by Sprawl integrates widely accepted measures of development density and projections of population growth with a new analysis of the comprehensive data on rare and endangered species that is compiled by the NatureServe network of state natural heritage programs. It shows that imperiled plants and animals are not found only in remote wildernesses; their habitat is often intertwined with where most people live. Although the nation's 35 fastest-growing large metropolitan areas (those with more than one million people in 2000) comprise just eight percent of the land area of the lower 48 states, they are home to nearly one-third (29 percent) of the imperiled species analyzed-nearly 1,200 species in all. And remarkably, 553 of these species (13 percent) are found only in the fast-growing large metro areas. At current rates of sprawl, by 2025 these rapidly spreading metro areas will convert an area equivalent to the size of West Virginia (about 22,000 square miles) from natural habitat to development.

Because each metro area typically comprises several counties, when the results are broken down by county they tell an even more alarming story. Under existing patterns of development, 18 counties are on track to use up all their non-federal farmland and habitat to accommodate projected growth by or before 2025. Examples include Cobb, Gwinnett, and DeKalb counties in the Atlanta area, Dallas and Tarrant counties in the Dallas area, Harris County in the Houston area, and Broward County in the Miami area. Another 19 counties will consume more than half of their open land in the same timeframe.

Many large counties where the greatest amounts of land are being lost are also home to high numbers of rare animals and plants. The problem is especially acute in California, home to more imperiled species than any other state. Within the 35 fast-growing large metro areas, eight of the top ten counties for imperiled species are in the Golden State. They include San Diego County with 99 species, Los Angeles County with 94 species, and San Bernardino County with 85. Other notable places where rapid growth threatens large numbers of imperiled plants and animals include the Las Vegas area (Clark County, 97 species), Phoenix (Maricopa County, 22 species), and Florida (the Miami, Orlando, and Tampa-St. Petersburg areas). The seeming anomaly in the group is Shelby County, Alabama, a suburb of Birmingham that is currently home to 27 imperiled species, and is the fastest-growing county in the state.

"Forests, wetlands, and grasslands in and around cities and suburbs are essential habitat for many imperiled species, as well as the more common birds and wildlife that we know and love," said Bruce Stein, vice president for programs at NatureServe. "We need to value and protect these nearby open spaces for wildlife habitat just as we do far-off national parks and wilderness areas."

The study also highlights the forward-looking efforts of some localities to identify critical habitats and preserve them even as their regions grow. Drawing on these best practices, the report recommends tools and strategies that local governments can employ to protect open space and biodiversity, including creating and maintaining natural resource and species inventories, establishing regional cooperation, developing green infrastructure protection plans, protecting critical natural habitats, and building reliable local funding sources for habitat protection.

"The bottom line is, we live where the wild things are," said report co-author Reid Ewing, a professor at the National Center for Smart Growth and in Urban Studies and Planning at the University of Maryland. "We need to do a better job accommodating the natural environment along with the human environment. With proper planning, it doesn't have to be a question of us versus them or development for people versus habitat for wildlife."

The report is available for download in PDF format from the National Wildlife Federation’s Web site.

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