America's vanilla landscapes mean more animals but fewer species

Knight Ridder NewspapersApril 20, 2005 

WASHINGTON—Wisconsin officials last week toyed with the idea of shooting 2 million stray cats. With white-tailed deer overrunning suburbia, a New Jersey environmental group wants more, not less, hunting. Fort Worth, Texas, may enlist downtown merchants to shoot firecrackers at an estimated 1 million noisy grackles.

Battles to curb the spread of Canada geese, beavers, kudzu, raccoons, house sparrows and European starlings are already pretty much lost. Residents of suburban Detroit and other regions are trying to cope with increases in voracious rabbits and stinky skunks.

These species—once considered benign if not cuddly—show that there can be way too much of a good thing.

Animal-vehicle crashes—on roads and in the air—cost America about $1.4 billion and claim about 200 lives a year.

What's happening, say conservation biologists, is a good Earth Day lesson. America's landscape is becoming homogenized, looking very much the same. That means certain generalist species—such as deer and Canada geese—thrive, while specialist species that live in unique landscapes, such as the Cerulean Warbler, a songbird considered vulnerable and found in the eastern half of the United States, are in trouble.

"Some things get out of balance," said Smithsonian National Zoological Park research scientist John Rappole, who co-wrote a book on deer overabundance. "As humans, you have to create yourself a little space, and some of these things are definitely imposing on our space, like the deer and the grackles."

That imbalance helps some wildlife thrive.

"We've modified landscapes or ecosystems so that some species—whether they are invasive or not—become overabundant," said Norman Christensen, a leading ecologist at Duke University. "The homogenization of our landscapes around particular habitats tends to favor certain species and disfavor others."

Some have even compared the smothering effects of adaptable wildlife to the ubiquitous retailing giant Wal-Mart.

"The more adaptable animals are surviving," said Rachel Brittin, the spokeswoman for the International Association of Fish and Wildlife Agencies. "It's the Darwin theory: survival of the fittest, and Wal-Mart is a good example."

In Fort Worth, where the noise of great-tailed grackles roosting in downtown trees can be overwhelming, experts realize they're up against a tough enemy. "The grackles have become one of those readily adaptable species; they're the king on Darwin's bird charts," said acting parks director Randle Harwood.

However, what's happening isn't natural. It's all man's fault. As the land is changed, often to accommodate development, ecosystems turn much more vanilla, scientists say.

The world does better when it has a buffet of diverse species—some of those plants and animals can benefit people with food and medicine—instead of one flavor fits all, said Oregon State University zoology professor Jane Lubchenco, president of the International Council for Science.

Scientists have even started calling this the Homogecene epoch, much like the Pleistocene epoch.

"It's an increasing problem. When many species don't have their natural control agents and landscapes are being controlled to the detriment of their natural enemies or predators, they are running amok," Lubchenco said. "It's something that society's going to have to come to grips with and that doesn't mean shooting them all."

Eric Stiles, a wildlife biologist who became the vice president for conservation at the New Jersey Audubon Society, says the problem is the specialist species that lose out: Northern Goshawk, timber rattlesnake, marbled salamander, Pine Barrens tree frog.

"As you homogenize the environment and reduce the number of niches and dumb down the environment, what is going to result is a huge loss in specialists," Stiles said.

And the voracious generalists aren't helping matters either. At New Jersey's Forsythe National Wildlife Refuge, the non-migrating Canada geese feast on lawns, golf courses and wetlands, foraging food that other migratory birds then won't get to eat.

"They keep the impoundment looking pretty much like a putting green," said refuge manager Steve Atzert. "There's not much food for the fall migrants when they come down. ... They keep the cupboard pretty bare. The stuff you'd like to raise and produce for the migrating flocks never show up."

Humans are also paying a price.

In 2003, 210 Americans died in crashes with wildlife—77 percent of the animals were deer—according to the Insurance Institute for Highway Safety. That's twice as many fatalities as there were 10 years earlier.

Repairing damage to cars and trucks costs about $1 billion a year and damage to airplanes from bird hits is about $400 million a year, according to a report by the U.S. Government Accountability Office.

Deer also carry ticks that spread Lyme disease. Beavers are diverting streams away from where they are needed. And droppings from Canada geese have become water quality and public health issues.

"The scary thing is that people are now viewing wildlife as pests," the wildlife association's Brittin said. "But, in fact, we're encroaching on their territories by building our cities in wild areas."

The poster child for overabundance is deer. Experts don't even know how many deer there are because they keep multiplying while counting efforts go on.

Just 80 years ago, deer were in trouble in North America, so hunting was limited. With no natural predators, the deer came back in force.

And deer—like Canada geese—love the lush lawns of suburbia.

"Your chemical cocktail lawn is like a free food display for deer," Audubon's Stiles said. "They're responding to the habitat we've created."

And the deer "are doing what deer do, which is eat" and that's a problem because they're also nibbling on young trees in forests, keeping them from growing, said Christopher Rosenberry, a supervisor for the Pennsylvania bureau of wildlife management.

The Smithsonian's Rappole said deer are the biggest problem in suburbia where there's no hunting.

And hunting appears to be the solution. The trouble is not enough hunting, according to state regulators in Pennsylvania and the wildlife associations. The New Jersey Audubon Society last month took the unprecedented action for an environmental group by issuing a report last month that said the deer harvest needed to increase for the health of the rest of the ecosystem.

In fact, hunters in Pennsylvania have clashed with wildlife regulators because the state wants more hunting and many hunters prefer to keep the deer population big so that they are easier to find.

Rosenberry said his state has been "very aggressive" in encouraging the hunting of female deer. Last year, Pennsylvania issued more than 1 million licenses to kill female deer.

"There has been some progress made," Rosenberry said.

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For more information, check out the following Web sites:

A report by the International Association of Fish and Wildlife Agencies on overabundance of wildlife and how hunting is used to keep the problem in check: http://www.iafwa.org/Attachments/PotentialCostsofLosingHuntingandTrapping.pdf

A U.S. Government Accountability Office report on reducing wildlife damage: www.gao.gov/new.items/d02138.pdf

The Insurance Institute for Highway Safety recent figures on animal-car crashes: www.iihs.org/news_releases/2004/pr111804.htm

A study on the trend of homogenization of ecosystems in a scientific journal: http://rydberg.biology.colostate.edu/poffpubs/Olden%20etal2004(TREE_homog).pdf

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(c) 2005, Knight Ridder/Tribune Information Services.

PHOTOS (from KRT Photo Service, 202-383-6099): nature

GRAPHIC (from KRT Graphics, 202-383-6064): nature

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