Wild Life in the Concrete Jungle
- From coast to coast, urban areas are teeming with birds, bats and other beasts, giving city dwellers a chance--for some, their only chance--to observe wild animals
- Jun 01, 2006
PALE MALE and Lola didn't know they were urban pioneers. They were just looking for a nice home, a place to raise a family. And in March two years ago, the pair of red-tailed hawks seemed to have found the perfect spot, a 12th floor cornice on a condo in the heart of New York City.
That's when the fight began. Some condo owners were not pleased with the idea of two birds of prey homesteading over their windows, bringing bloody rodents to eat and dropping waste on their fancy balconies. So they removed the hawks' nest and the pigeon guard that was supporting it.
But the owners forgot to take into account New Yorkers' love affair with wild species, especially those tough enough to make it in the city's concrete jungles. Within 48 hours, protesters began a round-the-clock vigil outside the building, demanding that the hawks be given back their home. The story made headlines not only in New York but around the world. Under fire, the condo owners relented and installed a new pigeon guard on the cornice. By the following March, Pale Male and Lola were building a new nest.
The lesson: While cities and suburbs may seem like hostile worlds for wildlife, many of the same creatures that roam deep woods or soar over pristine canyons thrive in the urban world. And despite the occasional conflict, these animals bring something profoundly valuable to human life. "I hear all the time of people saying what a wonderful experience it is to see a fox in their yard," says John Hadidian, director of the Humane Society of the United States' urban wildlife program.
Indeed, many metropolitan areas are teeming with wildlife. New York's Central Park is one of the country's best birding sites, with 285 species spotted there to date. Black bears hibernate happily in crawl spaces of suburban New Jersey homes and explore Wisconsin shopping malls. Coyotes roam backyards in the heart of Tucson, Arizona, and even hunt within a few miles of the White House. Hundreds of species, from Canada geese to cottontail rabbits, are now reaching population levels never seen before, thanks to their ability to adapt to urban landscapes. "This is probably the first time in our history that so many people have had a chance to experience so many animals so directly," says Hadidian.
Urban wildlife benefits from both abundant food and surprisingly good habitat. For a peregrine falcon, a perch atop a skyscraper or tall bridge is just as good as--or maybe better than--its usual high cliff vantage point for spotting and diving down on prey. White-tailed deer, once nearly exterminated in the Northeast, now number in the millions, their population boom fueled by suburban tulips and vegetable gardens and the absence of predators. When Charles Nilon, an urban wildlife ecologist at the University of Missouri–Columbia, did a bird survey in Baltimore, Maryland, he found the city housed at least a third of the species that inhabit the entire region, including black-crowned night-herons, indigo buntings, scarlet tanagers, white-breasted nuthatches and a variety of warblers.
But if many animals have prospered with the offerings of urban landscapes, city-dwelling humans actually may be getting the better of the bargain--an opportunity to experience wild animals without having to venture to Yellowstone or a tropical rain forest. "All of our senses and capabilities, even our spiritual capacities, are based on ongoing contact with the natural world," explains Stephen Kellert, professor of social ecology at Yale University. "Contact with nature is essential to our health and physical well-being."
Clearly, wild creatures bring something special to the lives of the city-bound. "Survey after survey says that people love seeing deer," says Ricky Lien, an urban wildlife specialist for the state of Wisconsin. The sea lions cavorting off the piers of San Francisco are as much a feature of the city as are cable cars. In downtown Austin, Texas, urbanites take paddle-wheel cruises on Town Lake and line the banks by the thousands to watch the spectacular sunset exodus of more than a million Mexican free-tailed bats from under the famed "bat bridge."
National polls show that 40 percent of U.S. households do something to attract wildlife to their homes, from installing bird feeders or ponds to planting the creatures' favorite shrubs and flowers. "People have a deep fascination with birds and other wild creatures," says Kevin Coyle, NWF's vice president for education. "They want animals near their homes because it gives even the most urban setting a special, magical feel."
From these wild encounters comes a joy that's somehow different from the pleasure we get from iPods, nightclubs or morning coffee from Starbucks. Kellert recalls strolling with friends and visitors through New Haven, Connecticut's urban East Rock Park, and suddenly spotting a river otter or a wood duck. "You can't begin to capture the excitement and childlike thrill people of all ages get from that," he says.
Scientists are also beginning to realize that the urban environment can play a surprisingly important role in conservation. Historically, sprawling metropolitan areas were viewed largely as "sacrifice zones" for biodiversity. To preserve species, biologists instead looked to parks and preserves. But because protected areas make up only about 5 percent of the world's land surface, "promoting urban wildlife is not purely a matter of providing entertainment for people," says William Shaw, chair of the wildlife and fisheries science department at the University of Arizona. "It is a crucial component of maintaining biodiversity."
Indeed, in some rare instances, cityscapes are now better habitats for endangered species than wilderness is. Take the peregrine falcon, which was down to just 39 known nesting pairs in 1970. When scientists started breeding the birds and reintroducing them to the wild in the early 1970s, "we had problems with predation," recalls William Burnham, president of the Peregrine Fund. Great horned owls and eagles swooped down on the nests and took a deadly toll on young birds. The scientists decided that cities would be safer for the falcons--not to mention chock-full of nutritious pigeons and starlings. They began to release the birds in Washington, D.C., Baltimore, New York and other big metropolitan areas. The plan worked. The falcon has been removed from the U.S. Endangered Species List and is now nesting securely on skyscrapers, bridges and other lofty man-made perches. "New York City has probably the highest density of nesting peregrines anywhere in the world--about 14 pairs," says Burnham.
The notion of cities as wildlife sanctuaries has consequences for conservation planning. One crucial insight is that urban areas need to provide corridors, or links, between more pristine habitats. In the Southwest, for instance, the mountain lion is making a comeback, yet the species' long-term health is threatened by increasing separation of the cats' home territories. "Roads and cities may isolate them in 'islands' inadequate to support viable populations," explains Shaw.
One solution is establishing paths along which the cat can cross from one section of its territory to another. In Southern California, for example, mountain lions now pad through culverts under eight-lane freeways to travel between previously isolated habitat patches. In cities and suburbs, bands of vegetation, perhaps along a stream bank, can provide similar corridors that benefit a wide range of species. A growing number of cities have started to do such biological planning, including Tucson; Portland, Oregon; Seattle; Boulder, Colorado; and Columbia, Maryland.
Some scientists, meanwhile, are studying the unique challenges faced by urban wildlife--and how to better defuse the inevitable conflicts between critters and humans. Admittedly, the research is just beginning. "There is a dearth of good studies about urban wildlife ecology," says Hadidian. "Academics would rather be in Yellowstone with bears than studying wild animals in the city."
Still, a handful of intrepid biologists have exchanged the wilderness for city streets. In Tucson, for instance, Shaw's colleague William Mannan has been probing the fate of raptors such as Harris' and Cooper's hawks. These birds of prey have a good life in the city, with droves of quail, doves and rabbits to hunt, but there is also a lethal hazard the birds do not face in the wild: electrocution on power lines. Mannan has come up with a simple fix--installing protective devices, costing just pennies each, that shield birds when they land on transformers.
Other dangers are more difficult to remove. Peter Marra of the Smithsonian Institution's National Zoological Park has looked at the reproductive success of birds in both rural and urban habitats. He found that avian city dwellers actually do better getting through the nesting period because they have fewer predators such as snakes and raccoons. But once the urban young are out of the nest, they face a harsher world. "They are more likely to get nailed by cats," says Nilon.
Another hazard can be human hostility. Deer especially are now viewed as pests in many parts of the country. It's one thing to catch a rare glimpse of a buck in the woods; it's another to lose valuable landscaping plants or risk having the animals crash through your windshield, which is why it's becoming less controversial to cull some deer populations.
With other species deemed nuisances, cities have had success using less lethal methods. In Michigan, for example, state biologists decided to learn what would happen when they took the eggs and nests away from Canada geese, which were then radio-tagged. "Eight of 10 birds that normally would have raised young in the Detroit metro area left and migrated north," says Hadidian. "They sat on the Canadian tundra for six weeks and did what geese used to do, which is to migrate and not be in city parks."
Stories like these raise hope that humans and wild creatures will increasingly find ways to get along, bringing enormous benefits for both. The right kind of city planning may not only boost wildlife numbers, it can also make our urban world more livable--and offer city dwellers a vital connection with nature. "We have a fundamental need to know that there is more than just ourselves in the world--that all of life is related," says Kellert. Whether it is a red-bellied woodpecker outside our window, a fox trotting down a boulevard median or a pair of red-tailed hawks nesting on Park Avenue, the wild creatures in our midst make both the natural and urban worlds immeasurably richer.
John Carey is a senior correspondent at Business Week covering science, technology and the environment.
Close Encounters: Keeping Wildlife Wild
Sometimes urban wildlife gets just a little too close for comfort. Below are a few tips for discouraging some of the most common creatures homeowners consider nuisances:
Raccoons: Cover trash cans securely; cap chimneys and repair loose shingles and vents to keep the animals out of the house; leave a radio on in an attic to chase away raccoons that already have set up housekeeping.
Deer: Surround your garden with plastic deer fencing at least 6 feet high; spray a nontoxic deer repellent on the most vulnerable plants.
Geese: It's a crime to disturb nests without a federal permit, so contact your local animal control agency or a group like Geese Peace for help.
Crows: Store your trash in securely closed plastic bags; do not leave pet food outside.
Science in the City
Traditionally, wildlife biologists dismissed cities and suburbs as potential study sites, preferring to head off to the wilds of Amazonia or Yellowstone. More recently, however, many of these researchers are discovering that urban areas can be ideal&151;not to mention accessible--places to study the distribution, behavior, ecology and evolution of wild creatures.
Take Joel Brown, an ecologist at the University of Illinois at Chicago who studies squirrels. Though they are probably the most abundant and conspicuous wild mammal in U.S. cities, very little is known about squirrels, says Brown, who's made it his goal to change that. Targeting Chicago and its suburbs, Brown is looking at where squirrels live, how many there are, what foods the animals need, how the city's two squirrel species (gray and fox) interact, and even possible evolutionary changes in response to pressures of the species' urban habitat. To gather as much data as possible, Brown and his colleagues have developed an Internet "citizen science" site, Project Squirrel (http://squirrel.bios.uic.edu), where volunteers can enter their own observations of Chicago squirrels.
Though the research remains in its early stages, Brown and his colleagues have made a few interesting discoveries. They've found that squirrels are more abundant in Chicago's northern suburbs than other parts of the region, for example, a finding the scientists attribute to leash laws in the north. Elsewhere around the city, they say, loose dogs and cats may be killing off squirrels, or at least discouraging them from settling down. If a neighborhood has no squirrels at all, adds Brown, it's probably because it houses a lot of rats, fellow rodents that compete with squirrels for food.--Laura Tangley