Paved Over and Pushed Out

Urban spawl poses a serious threat to wildlife and habitat

  • T. Edward Nickens
  • Aug 01, 2001
A NARROW GAME TRAIL coursed through saw palmetto, hugging the edge of a swamp deep in Florida’s Big Cypress National Preserve. I followed the faint path, eyes on the ground. Shin-high cypress knees snagged my boots. Mosquitoes buzzed my ears. The trail skirted a hammock of soaring cabbage palms, their fronds rattling in a dry November breeze.

Just a few hours earlier, a Florida panther had walked this path. I’d seen its tracks from a jeep traversing this muck of pine flatwoods and cypress stands. Scrambling off the vehicle, two biologists and I plunged into the dense woods, picked up the panther’s trail through towering live oaks, and tracked it back to the trail crossing.

At the edge of the trail, in a thicket of wax myrtle and red bay, the big predator had stopped, sinking its front paws deep into black mud. Something had caught the cat’s eye--the left edges of the tracks were pushed slightly deeper into the soil, as if it had leaned in that direction, raising a tawny muzzle. Perhaps the panther had caught wind of a deer, a primary prey animal, or glimpsed an armadillo scuffling through the briars. I couldn’t tell. But this much I did know: There are roughly 60 adult Florida panthers remaining in the world, and one of these magnificent felines had been standing right here, sifting the air for scent, pondering its next move.

In the three-quarter-million-acre Big Cypress preserve, that panther had plenty of options. Not so its kin in the surrounding region. Rich upland forests to the north and west are ideal habitat for the big cats, but they also are home to one of the nation’s fastest-growing human populations. Kneeling beside the fist-sized panther tracks we’d discovered, Kris Thoemke, a biologist for the National Wildlife Federation’s Everglades Project Office, sounded a rueful note. "This is wild country," he said, "but it’s also the front line for the battle over urban sprawl and wildlife habitat."

Long cited for its pernicious effects on the quality of human life, from increased traffic to air and water pollution, urban sprawl is also putting the squeeze on wildlife as diverse as panthers, bears, birds, fish and mussels. From the outskirts of Naples here in Florida to the growing footprints of major cities in Georgia, California, Arizona and beyond, ever-expanding suburbs are gobbling up millions of acres of wildlife habitat every year. Local officials have begun to grapple with solutions to the problem, but it’s still too soon to predict whether relief will come in time for the most vulnerable species.

Sprawl’s impact on wildlife goes beyond the obvious. More roads and cars spawn air and even water pollution (when gas and oil run off roadways into streams). Land clearing also loads streams with sediment, which smothers fish eggs and bottom-dwelling invertebrates and chokes out streamside food and cover plants. And simplified suburban landscapes give exotic and weedy competitors an edge over natives. Even if patches of land are left undeveloped, sprawling growth often swallows up niche habitats, taking away the homes of species that depend on specialized ecosystems. Wide-ranging animals, meanwhile, which need large, contiguous blocks of wild or semi-wild landscape, find themselves hemmed in by roads, golf courses and new neighborhoods.

That’s the case with Felis concolor coryi, the Florida panther. A subspecies of North American mountain lion, Florida panthers can be identified by three distinctive physical features: a right-angle crook near the end of the tail; irregular white speckling on the head, neck and shoulders; and a cowlick in the middle of the back. The cats are impressive creatures, with mature males growing some seven feet long from nose to the black tip of the tail.

Preying mostly on white-tailed deer, Florida panthers are solitary hunters, and the cats need space. The home range of male panthers averages about 185 square miles, and an individual might roam 20 miles during a single day. In the past, the animals ranged from the southern tip of Florida north to South Carolina and west to Texas, but--after being overhunted until 1958--they are being crowded out by human development. Today the only remaining population is in southwest Florida, where new highways, condominium complexes and golf-course communities threaten the cat’s survival.

It’s easy to see what’s happening to prime Florida panther habitat. Forty miles west of those pawprints in the mud sits Naples, the seat of Collier County and the nation’s most active new residential construction market. The county’s population grew from 86,000 in 1980 to 227,000 in 2000, and it is projected to double again in the next three decades. According to NWF attorney John Kostyack, state and federal authorities have approved the destruction of 6,000 acres of panther habitat since 1993, with at least 29,000 additional acres under threat of development.

One morning I crisscrossed the cat’s last stronghold by car. Leaving downtown Naples, I drove north, through miles of sprawling shopping centers and gated golf- course developments. As the occupied neighborhoods petered out, new developments under construction appeared as huge holes bulldozed out of the forest. Halfway to Fort Myers, I passed through a moonscape of bare earth several miles in extent. It turned out to be buildings that would support the new Florida Gulf Coast University--touted as a center for environmentally oriented programs--which is being carved out of cypress woods and palmetto groves known to harbor panthers. Farther east into the countryside, "for sale" signs whizzed by the window--130-, 320-, 670- and 1,006-acre projects.

Such leapfrog development is one of urban sprawl’s more insidious characteristics, and Florida by no means has cornered the market. According to the Natural Resources Defense Council (NRDC), suburban populations have grown ten times faster than urban ones in the country’s largest metropolitan areas since 1980. In Maryland, more open space will be converted to housing between 1995 and 2020 than during the last 350 years. Phoenix is developing 1.2 acres of land every hour. And the suburbs of Atlanta now sprawl for a linear distance of 110 miles. Still, there’s no end in sight: The U.S. population is expected to grow by half over the next 50 years. That’s the equivalent of adding all the residents of today’s Germany and France, note the authors of an NRDC book, Once There Were Greenfields, that outlines the perils of sprawl.

The Florida panther may be one of sprawl’s more charismatic casualties, but it is by no means alone. In Arizona, for example, the seven-inch cactus ferruginous pygmy owl is threatened by ever-spreading suburbs. A recent U.S. Fish and Wildlife Service survey located fewer than 35 adult owls throughout the entire state, and all but two were found in Tucson’s rapidly growing Pima County, where human population has increased from 400,000 in the early 1970s to nearly 850,000 today.

In the Southeast, a hand-sized freshwater mussel called the Carolina heelsplitter was once found in streams throughout the Piedmont region of the Carolinas. Today the mussel, a federally listed endangered species, is found in only six creeks, and each of them lies directly in the path of sprawling Charlotte, North Carolina. New driveways, rooftops, streets and gutters there have worsened storm-water runoff, which in turn scours creek banks, silts up clear streams and washes mussels into poorer downstream habitat. According to John Alderman, a wildlife biologist with the North Carolina Wildlife Resources Commission, all six remaining heelsplitter populations are significantly threatened by Charlotte’s expansion. "If you’re an aquatic species," he says, "this is not a very pleasant place to live."

Nor is sprawling Seattle for endangered chinook salmon. Migrating from Puget Sound up the region’s rivers to spawn, these fish run the gauntlet of Seattle’s exploding megapolis, especially those that swim the Cedar River. While upstream stretches of the river include some of the area’s highest-quality aquatic habitat, sprawl is threatening to siphon off more and more of its water. A recently approved plan negotiated by city, state and federal officials guarantees Seattle’s burgeoning population more than 100 million gallons of Cedar River water each day, and fishery managers are worried that there soon may not be enough left over for the fish. Already, 22 of 25 stocks of Puget Sound salmon fail to meet U.S. Fish and Wildlife Service spawning goals for the species.

In Southern California’s San Diego County, so many wildlife species are threatened by sprawl that it’s difficult to hold up just one example; the county is home to more endangered species than any other in the contiguous United States. Sprawl’s victims include populations of the California gnatcatcher, arroyo toad, fairy shrimp and peninsular bighorn sheep--all listed by the federal government as either threatened or endangered. Particularly hard hit are coastal sage-scrub habitats--important to a wealth of wildlife species--which have declined some 60 percent since 1945. Inked in 1998, a multi-agency conservation strategy for 85 imperiled species is lauded for targeting 171,920 acres of habitat for protection in San Diego County, but conservationists worry there will not be enough money for acquiring, monitoring and managing the protected lands.

Indeed, enumerating solutions to urban sprawl is far easier than putting them into practice. Yet change is possible. Most ideas are bundled loosely within a platform of "smart growth" policies intended to prompt cities and towns to plan neighborhoods that mix offices, shops and homes and make work and play accessible by foot, bicycle or public transit.

Instead of encouraging sprawl into rural areas through large road-building projects, for example, municipalities are persuaded to "infill," or direct new growth to already settled areas. Urban growth boundaries, which stimulate growth inside a prescribed boundary, make it more attractive for developers to build inside an urban core than at its rural fringe, drawing a line in the woods or desert or prairie beyond which sprawl is curtailed. Despite technical problems and some entrenched resistance to such changes, there now are enough smart-growth success stories to suggest that urban sprawl is not necessarily the way life has to be.

Consider Portland. Like all Oregon cities, it was required by state law in 1973 to draw an urban-growth boundary around its metropolitan core and to discourage dense development outside the line. But Portland went even further, enacting the Metro 2040 Growth Concept, a municipal document outlining how, and where, the region plans to grow into the middle of the twenty-first century. Specifically, Metro 2040 promotes the development of mixed-use centers: communities that offer employment, housing, retail shops and both cultural and recreational amenities in a walkable environment serviced by public transit. Already, mass transit use in Portland is increasing at a faster rate than automobile use, and the Metro 2040 concept, when fully implemented, will cut road construction by 25 percent and save 100,000 acres from development. All this, and the plan still makes room for 720,000 new residents.

Just outside Washington, D.C., Maryland’s Montgomery County tried a different approach to curbing sprawl: a program that helps stave off the conversion of farmlands to residential subdivisions. Under the plan, launched two decades ago, property owners within a designated agricultural-reserve area are allowed to sell a parcel’s development rights to another party--such as a developer or real estate investor--and those rights are then transferred to a land parcel within an urban area. Known as a "transfer of development rights" (TDR) program, the swapping scheme leaves farmlands as open space while generating income for landowners. To date, 41,270 acres of land have been saved through the program--prompting The Washington Post to dub Montgomery County "the land that suburban sprawl forgot."

Still, cities seeking to curb sprawl face many challenges, and South Florida’s attempts to grow smarter show just how difficult the effort can be. Collier County, for example, is under a state-imposed moratorium on new building permits, handed down in 1999 when its growth-management plan was deemed unsuitable by state officials. Though the county has since set up an urban boundary, large-scale developments were allowed to move forward just outside it, prompting protests from the Florida Wildlife Federation and other conservation groups. Two years ago, county natural resource managers proposed a TDR program as well as a zoning effort to preserve farmlands, but county commissioners rejected both ideas.

Yet planning advocates say such resistance to curbing sprawl represents little more than the growing pains of an effort to instill into the public mind a whole new way of thinking about development. NRDC senior attorney F. Kaid Benfield, co-author of Once There Were Greenfields, points out that we’ve spent many decades creating today’s sprawling suburbs, yet just a few years talking about solutions. "I’m encouraged that there’s so much more interest in this issue than there was five years ago," he says.

But will changes come in time to save species like the Florida panther? The day after I tracked that big cat through live oaks and cabbage palms, I took a walk on the beach in downtown Naples. Looking north, the Gulf Coast curved into infinity, a shore crowded with condominiums, homes and high-rises, like polished, close-set teeth, for as far as I could see. The region’s rabid development began on this thin fringe of beach, and from here the growth spread inland, where it now has a life of its own, an appetite made greater with each new gated golf-course community. The sand was fine and white, and in the soft beach my hiking boots left clear lug impressions. I thought of those panther prints in the Big Cypress mud, where the cat stood in the underbrush, sweeping the trail for signs of prey and hints of danger. Stepping out from the protective scrim of scrub, the panther crossed a muddy wash crisscrossed with alligator tracks, then padded quietly towards a hammock of high ground. For the moment, all seemed well and safe.

A frequent contributor to the magazine, North Carolina writer Eddie Nickens wrote about Smoky Mountain wild-herb bandits in the February/March issue. 

Protecting Wildlife Habitat From Sprawl

NWF’s Smart Growth and Wildlife campaign is working across the United States to protect and restore wildlife species and habitats threatened by urban sprawl--specifically by promoting smart-growth alternatives that are gaining increasing public support.

Smart-growth communities plan and build neighborhoods that are alive with a mix of offices, shops and homes, most of them easily accessible by foot, bicycle or public transit. Smart growth also means protecting open space and watersheds for wildlife and plants by directing new growth to already settled areas.

To promote such ideas, NWF is hosting a series of conferences and workshops around the country. The first was held last spring in San Diego, with another scheduled for this fall in Seattle. Providing a boost to smart-growth advocates in California, NWF documented sprawl’s effects in that region in a recent report, Paving Paradise--Sprawl’s Impact on Wildlife and Wild Places in California.

In Florida, NWF’s Everglades Project Office, which participates in the national campaign, now considers sprawl its number-one priority. "The problem goes beyond threats to the Florida panther," explains NWF biologist Kris Thoemke. "When we lose panther habitat, gopher tortoises, Neotropical birds and a host of other organisms all suffer."

To stave off further destruction of panther habitat in South Florida, NWF, its affiliate, the Florida Wildlife Federation, and several other groups have filed a lawsuit against the U.S. Fish and Wildlife Service, the U.S. Army Corps of Engineers and the Federal Highway Administration. They’ve charged these agencies with fostering sprawl within the panther’s critical habitat--in clear violation of the Endangered Species Act--through permitting, planning and funding activities. According to NWF attorney John Kostyack, the federal agencies already have approved dozens of new building projects, including a major parkway, that endanger the big cat. "Chipping away at panther habitat one project at a time is a recipe for extinction," Kostyack says.

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