Urban wildlife is teaching us something about what we've lost
SEATTLE, Wash. - It doesn't seem too difficult to trap a crow. Especially if you're armed with a remote-controlled, rifle-powered, 25-foot-square net and a heap of stale white bread. Especially if you've seen the crow in question almost every day for the past six years. Especially if it lives just a couple of wingflaps from your own suburban backyard.
It's harder than you might think.
"Bastard!" explodes John Marzluff, an otherwise even-tempered wildlife biologist from the University of Washington. He tosses the remote control for the net gun on the dashboard of his truck and tries to take a deep breath.
For the second time on this gray, low morning, he's pushed the button on the remote, and for the second time exactly nothing has happened. No net has shot out of the ferny underbrush, no panicked crow is struggling for freedom, no one is running forward to fit the bird with an identifying leg band. Instead, less than 100 yards down the conifer-edged road, a female crow is strutting well within range of the stalled net, stuffing her beak with bread.
Marzluff has spent his career studying crows and ravens in Arizona, Maine, Idaho, Montana, Hawaii and Guam. He and his students have banded about 500 crows in the Seattle area, but the job doesn't get much easier with practice.
"The more you try to trap crows," he sighs, "the shorter your lifespan."
Crows and their cousins in the corvid family, ravens, jays and magpies, have spent hundreds of thousands of years taking advantage of our inventions. Today, they forage in dumps and on suburban lawns; they follow hunters to prey and backpackers to campsites; they nest on Alaskan oil rigs and in the ornate stonework of city libraries. They've been known to perform pitch-perfect imitations of explosions, revving motorcycles and flushing urinals. They're fiercely, exasperatingly smart.
It's all too easy for crows to survive in the Seattle suburbs, where they have free access to truckloads of tasty human castoffs. While many species are forced to flee the expanding rings of development, crows and a few other hardy creatures are rushing in like bargain-hunters on their way to a flea market. Like it or not, our backyards are hosting an evolutionary showdown, and the odds favor the coyotes and the crows: The coyote is the only mid-size carnivore that is actually expanding its range in North America; the American crow, once rare in the Pacific Northwest, is now one of the dominant birds in the Seattle area.
The showdown is pressing many Seattle residents - and the rest of us - up against an awkward truth. Though we might like our cities neatly separated from the natural world, nature is having none of that. Wild animals are reacting and adapting to us as fast as they can, not just to our logging and mining and ranching and fishing, but also to our fast-food restaurants, golf courses and campgrounds.
Marzluff and a few of his colleagues are proving as adaptable as the animals they study. In recent years, they've moved their research out of the wilderness and into the suburbs. By shadowing the animals that shadow us, they're discovering how we might protect other, less adaptable creatures from being elbowed out by the flood of newcomers.
"Crows are a perfect mirror for us," says Marzluff. "They're a good species for people to look at, not because crows are doing something wrong, but because we're doing a lot wrong - and they're taking advantage of it, every step of the way."
Ever since the late 1800s, when Seattle was little more than a staging ground for the Klondike gold rush, the city has had an irony-laden relationship with wildlife. Even then, city boosters were promoting Seattle as nature's next-door neighbor, a place that provided a quick escape from the distractions of urban life. Seattleites were also doing their damnedest to control the natural processes around them, and they dug waterways and filled tidelands as busily as any beavers.
Despite boosters' best efforts, wildlife refused to cooperate. Muskrats undermined a dam in central Seattle in the early 1900s, causing major damage to the Fremont Bridge, and so many frogs filled a canal near the Duwamish River that residents feared for local water quality. In the 1930s, city park officials encouraged the feeding of birds, hoping to please nature-loving visitors, but the mobs of geese and other waterfowl polluted Green Lake with droppings, uprooted flowers and shrubs, and created an uproar among local residents.
By the 1990s, the city had transformed itself. It was the hippest spot on the West Coast, with a Microsoft-powered economy, a caffeinated sensibility and an influential downtown music scene. More than half a million people moved to the area during the decade, many of them young, college-educated and eager to be nature's neighbors.
Instead of the peaceful, outdoorsy life they envisioned, the newcomers encountered some very urban problems, including a desperate housing crunch and some of the worst traffic tangles in the country. They also encountered crows - lots of them.
Suburban housing developments and landfills "are like a banquet" set especially for crows, says Marzluff. "We're creating hundreds of acres of crow habitat every single day," he says. "We're creating habitat faster than the crows can fill it."
Like humans, crows tend to breed in the food-rich suburbs. Juveniles without established territories spend more time in the poorer habitat downtown, moving back into the 'burbs when they find mates. (Marzluff and his students, who track the movements of their banded and radioed birds, call these adolescent wanderers the Young Urban Crows, or "yuckies.")
This survival strategy has been a wild success: The area's crow population has grown by as much as tenfold in the past two decades, and it grew by more than 30 percent just last year. It's one of the fastest-growing crow populations in the world, and the birds are getting hard to ignore.
Crows peck at mossy cedar shingles, drink from gutters and find their way into downtown office buildings. Karen Rillo and Mike Mead, the owners of a nuisance-wildlife franchise called Critter Control, are on the receiving end of many of the resulting complaints. They've shooed a crow out of a Barnes and Noble in University Village, used reflective balloons to scare crows off rooftops, and advised sleepless homeowners to spook the birds by hanging a dead crow in a tree. But the noisy flocks often prove persistent.
"I'm taking it personally when five pillows over my head won't do the trick," Seattle resident Susan Brett told the Seattle Times. After a night of tossing and turning, she said, she spent the morning looking at newspaper ads for air guns.
Matthew Klingle, a history professor at Bowdoin College in Maine who wrote his Ph.D. dissertation on the environmental history of Seattle, says such conflicts haunt almost every city in the United States - and are particularly persistent in the West.
"People think about the West as nature's province, and they move to Seattle, Portland, Boise or Salt Lake City to be close to nature," he says. "But people also want clear boundaries. They want a divide between nature and culture."
Crows aren't the only animals causing headaches for their human hosts, and Seattle isn't the only city that's unintentionally making more and more room for crafty wildlife.
In Phoenix, hungry javelinas - knee-high wild pigs - can't resist the exotic landscaping in suburban yards. "I tell people that they're just putting an ice cream parlor on their corner," says Arizona Game and Fish wildlife biologist Joe Yarchin. His office, which handles more than 1,000 nuisance-wildlife complaint calls every year, deals with Gila woodpeckers that hammer at air-conditioning units, peregrine falcons that smear pigeon guts on downtown law-office windows, and most everything in between.
His typical call, though, has something to do with coyotes.
Like crows, coyotes have long been associated with humans. They're our companions and our guides, our jesters and our harassers in legends and myths. And also like crows, coyotes are having a high time in the suburbs. In recent decades, their populations have rebounded from the all-out extermination efforts in the first half of the 20th century, and they've started Dumpster-diving around urban parks and suburban backyards (HCN, 12/18/00: Still here).
Coyotes tend to keep a low profile. Though the Game and Fish office in Phoenix gets a lot of complaints about coyotes every year, not many of the animals are really causing any trouble. But during this year's painfully dry summer, a family of seven coyotes kept turning up in a tony Phoenix neighborhood; a group of skinny juvenile coyotes was seen hunting ducks in a suburban park; and more than a few cats and dogs came home with telltale battle scars.
Coyotes have also made themselves at home in Tucson, San Diego and Denver. They're regularly spotted in Oakland, Calif., and South San Francisco, and U.S. Geological Survey biologist Erin Boydston has begun to track several recently arrived packs in Golden Gate Park. In Portland, Ore., surprised public-transit employees found a coyote inside a city light-rail train, calmly curled up on a seat. The incident even inspired a song, "Light-Rail Coyote," an ode to Portland by the ultra-popular band Sleater-Kinney.
Of course, coyotes have moved into Seattle, too. Biologist Timothy Quinn, whose dissertation research on urban and suburban coyote behavior sent him striding down Seattle sidewalks with a radio receiver, heard reports of coyotes in the Woodland Park Zoo (where they were trying to eat some frightened peacocks) and in heavily visited Discovery Park on the edge of Puget Sound. Several years ago, a young coyote wandered into a downtown office building, where wildlife officials cornered it in an elevator. "That was one scared coyote," Quinn remembers.
Quinn, now the chief scientist of the habitat program for the Washington Department of Fish and Wildlife, says the suburbs are as much of a banquet for coyotes as they are for crows. When Quinn was collecting coyote scat for diet analysis, he walked the same routes every two weeks. "I always saw all these little cat collars ... at first, it didn't make sense to me," he says.
His analysis eventually showed that coyotes' single most important mammalian prey was the suburban housecat. Then, he says, "all those little collars started to make sense."
Biologists aren't sure how these urban and suburban coyotes affect their ecosystems, or how quickly changing, human-dominated ecosystems affect coyote behavior. Quinn says coyotes in Seattle might be a boon to songbird populations, since they pick off so many warbler-stalking kitties, but he can only guess.
John Marzluff's second crow-trapping stop of the morning is in a new subdivision, one packed with trimmed lawns, hopeful landscaping and cedar-shingled three- and four-bedroom homes. As we pull over to the curb and hop out, a sprinkler near our feet starts up with a sudden pfft.
Marzluff sets up his net gun, and we quietly settle in for another wait. Almost immediately, a flock of juvenile crows starts cawing on the next corner, and soon a small group of them begins circling the hill of white bread. Marzluff leans forward, remote control in hand, and - yes! - the blank rifle cartridges explode, the net soars out, and one young crow is stopped in its tracks.
A woman in a tailored black suit and heels pokes her head out of the nearest house, taking in the truck, the biologist and the unlucky crow. "What was that?" she demands. Marzluff explains and apologizes, and the woman shrugs, her curiosity satisfied for the moment.
Most biologists don't have to consider the effects of nervous neighbors, speeding cars or ill-timed landscaping work. They've long preferred to work in big nature, in wilderness areas and other places where nature's gears turn in relative peace. For decades, many have viewed cities as ecologically dead, places where natural processes stalled out long ago.
Marzluff likes studying the suburbs, not just because he's fascinated by the ingenuity of crows ("You get hooked on 'em," he says) but also because he's trying to figure out how other, less-adaptable species get by in the sea of subdivisions.
The total transformation of this landscape, along with the crows' habit of aggressive nest predation, should be a death sentence for any forest-loving animal. But in the struggle between the garbage-eaters and the habitat purists, some of the purists are turning out to be surprisingly tenacious.
Just a few hundred yards down the wide, curving road, a slender greenbelt snakes around the edge of the development. This tiny area, barely 45 yards wide and just over a mile long, is an unexpectedly effective wildlife refuge. Though the number of birds isn't nearly what it would be in an undisturbed stretch of forest, every feathered forest-specialist in the region has appeared here at one time or another. From the well-established trail, Marzluff points out a winter wren nest, a delicate, grapefruit-sized ball of moss.
This smidgen of forest may not be attractive habitat for long. Invasive plants may creep in, or curious cats and kids may disturb nesting patterns. But for now, the greenbelt is like an island with regular ferry service to the mainland. With a 150-acre University of Washington forest preserve just down the road, wrens and other birds can usually find the food, mates and habitat they need by traveling between the two areas. Marzluff and his colleagues at the University of Washington's Urban Ecology program have found that such well-managed small areas, interspersed with larger preserves, could go a long way toward maintaining stable populations of forest birds and other animals.
These hopeful results are probably a happy accident, since parks and green spaces are most often designed for us, not for wildlife. Parks are intended, overtly or not, to educate us, enlighten us, or entertain us; animals, if they appear, are usually just a pleasant diversion for passersby. Marzluff hopes his work will convince some planners to take a bird's-eye view.
"We don't want to just set aside habitat, we want to set aside functional habitat," he says. "We want to make sure we have a good mixture, that it's not all low-density sprawl."
He and a few other researchers argue that cities and other human-dominated places are far from dead environments. They say they're complex ecosystems, constantly in flux and well worth the attention of a new generation of ecologists. They hope to flush more of their colleagues out of the woods to investigate, and they're getting some high-profile support.
The federally funded National Science Foundation, which underwrites the work of the University of Washington's Urban Ecology program, also oversees a network of about 20 long-term ecological research stations. In 1997, the foundation chose Baltimore and Phoenix for its first urban research stations. The Phoenix station currently supports more than 50 projects, and many involve not only biologists but also economists, sociologists and urban planners.
Through her work at the Phoenix station, Arizona State University biologist Ann Kinzig has found that desert birds can also take advantage of habitat fragments in the city. Small neighborhood parks - "even places with playgrounds and baseball fields" - support rich populations of native birds, ones that seem to coexist with human-associated species such as rock doves and starlings. When she applied economic and demographic data to her findings, she discovered that bird diversity is significantly higher in wealthier neighborhoods, a tantalizing pattern she plans to investigate further.
The field of urban ecology still has a long way to go. "This research is where timber research was 20 years ago," says Andrew Hansen, an ecology professor at Montana State University who studies the impacts of rural subdivisions (see sidebar). In the early 1980s, he says, biologists knew very little about the effects of clear-cutting, but the lengthening roster of endangered forest species inspired concentrated research.
"We learned a lot about how the ecosystem worked, and we were able to figure out how to log more gently," he says. "We're just now realizing that rural and urban development is a serious issue in many areas. We're just beginning to come up with ways to live more lightly on the land."
In 20 years, this research will be even more critical. A recent study in the journal Bioscience reported that sprawl is already the top cause of species endangerment in the continental United States. In July, the American Farmland Trust estimated that 25 million acres of Western ranchland will be threatened by low-density development within the next two decades.
"Pretty soon," says Tim Quinn, "we're all going to be urban biologists."
Cities might offer fascinating ecological puzzles to a new breed of scientists, but is "living more lightly on the land" - especially in Seattle or Phoenix - really worth the trouble of finding out how to do it? After all, most wildlife habitat in our cities has been more or less permanently paved over, and what little is left seems to be dominated by crows, coyotes and hungry wild pigs. It's hard not to see our backyards as sacrifice zones. Even John Marzluff, who can see hope in 24 acres of scraggly conifers, isn't always optimistic.
"Studying urban ecology makes you a fan of the timber industry," he says flatly. "The amount of disturbance we create where we live makes all the other environmental issues we have pale in comparison."
But in the modern metropolis, even small conservation victories can be meaningful. In Seattle, as in most urban areas, humans have built on top of high-value wildlife habitat (low-elevation valleys and coastal areas) and preserved more scenic but less diverse areas (mountaintops and ridges).
"People think the wildlife is out there, in the national parks," says John Kostyack, head of the smart-growth and wildlife program at the National Wildlife Federation. "Contrary to popular belief, we've found that (the suburbs) are quite rich wildlife areas." His group is delving into the environmental records of U.S. metropolitan areas, and plans to release a report and a set of recommendations at the end of the year.
Other national environmental groups, including the Natural Resources Defense Council and the Sierra Club, have established sprawl-control programs that include habitat-protection efforts. Many land trusts, most notably The Nature Conservancy, focus on protecting privately owned wildlife habitat instead of generic open space. Land trusts of all sizes are using conservation easements to protect wildlife-friendly lands on the urban fringe.
Thanks to the Endangered Species Act, some city officials are also getting into the business of habitat protection. Seattle has limited logging and altered flows in the Cedar River watershed to protect the endangered Puget Sound chinook salmon. Tucson, like San Diego before it, is embroiled in a massive habitat-conservation planning process triggered by a suite of troubled species (HCN, 10/22/01: Healing the Gila).
In Seattle, the city-funded Urban Creeks Initiative has brought some of the poorest neighborhoods into closer contact with their nearby rivers, and transformed what were once seen as dumps and drainage ditches. Over the past decade, community groups on the southern end of Seattle have restored a peat bog and chopped out invasive plants in Longfellow Creek, while city agencies have piled up woody debris to slow down flows and make the waters more hospitable to salmon. This year, about 300 salmon came up the creek, among them a pair of Puget Sound chinooks.
Part of Longfellow Creek still runs under a Kmart parking lot, but many stretches are more accessible and more familiar to the whole community, says creek watershed specialist Sheryl Shapiro. "People are just astonished," she says. "They'll say ÔHey, I've lived here all this time, and I never even knew this was here.'"
In her book Flight Maps: Adventures with Nature in Modern America, historian Jennifer Price writes that "we have used a very modern American idea of Nature Out There to ignore our ravenous uses of natural resources." We have tried very hard to remain, as Woody Allen put it, "two with nature."
The Longfellow Creek Project and other community efforts suggest we may be able to treat our neurotic relationship with the natural world. Perhaps we can turn capital-N Nature into something we successfully coexist with every day.
The crows and coyotes might lend us a hand here. They might be able to, in an odd, roundabout way, help us solve the problem they represent. By busting through our comfortable ideas about where the city ends and Nature begins, our annoying, overbearing wild shadows might finally convince us that how and where we choose to live has a lot to do with the future of the natural world.
They make our options crystal clear: We can continue making endless habitat for crows and their adaptable colleagues, or we can try to make enough room for everybody. It's up to us.