What price would you place on the beautiful, musical and probably extinct ivory-billed woodpecker? Of course, all the world's gold couldn't bring the bird back. But suppose you could time travel back 60 years to the shrinking Southern swamps, where the last pairs were definitively seen. And suppose you made an economic argument for saving the birds' habitat. How much would you say the ivorybill was worth? Come on, let's hear a bid for the bird.

Environmental economists do these calculations all the time. They might point out that the ivory-bill helps local economies by attracting tourists who spend an average of $250 a day on food and lodging. They might find scientific data suggesting that the ivory-bill liver contains a treatment for brittle nails. And the resulting hand cream might net annual sales of $32 million.

The idea of fixing a dollar value on a species offends those who regard preserving our natural heritage as a moral imperative. It would seem akin to listing one's children on eBay.

"To evaluate individual species solely by their known practical value at the present time is business accounting in the service of barbarism," Harvard biologist Edward O. Wilson wrote in The Wilson Quarterly.

If providing numbers persuades the cost-benefit freaks to save these creatures and plants from extinction, let's make tons of printouts. Environmentalists need every weapon in the arsenal.

In an article titled "What is Nature Worth?" Wilson doesn't dismiss such calculations out of hand. But he finds that today's economic-value assessments make for a crude measuring device. They tend to low-ball the worth of a species over the long haul.

Consider the economic case for saving the endangered blue whale. The environmentalist would make the following points: Whaling nations have hunted the blue whale close to extinction. If they curtailed the harvest for a certain number of years, the whale population would recover and whalers could continue to make a living.

Well, not so fast. A 1973 study by economist Colin W. Clark found that had the hunters killed off all the blue whales and invested the profits in growth stocks, they would have made more money over the long term.

Wilson sees this conclusion as horrifyingly wrong because Clark freezes the market value of the blue whale (oil and meat) in 1973. "What was the value of the blue whale in A.D. 1000?" Wilson asks. "Close to zero." Its value 1,000 years from now is "essentially limitless."

Our imaginations cannot conceive of future uses for the blue whale. Gene-splicing, for example, is only in its infancy.

Likewise, our minds cannot grasp the potential for new whale-based pharmaceuticals. About 40 percent of the prescription drugs sold in the United States are now derived from wild plants, animals and microorganisms.

We don't even know most of the wild species currently in existence. Fewer than 2 million species have even made it to the scientific register. An estimated 5 million to 100 million or more await discovery.

But as ecosystems weaken, so does the possibility of finding nature-based cures. Over the past half-billion years, perhaps one species in a million disappeared on average each year. We now lose from 1,000 to 10,000 species per million every year. Once a species slips away, we will never know what it could have done for us.

Many environmentalists would like to throw out the calculators and appeal instead to the simple moral obligation to protect the nonhuman world. Ron Sider, founder of Evangelicals for Social Action, put it plainly: "Let's save endangered species because they come from the loving hand of the Creator."

But for those who demand the handiwork of accountants, numbers are also available.

To find out more about Froma Harrop, and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate web page at www.creators.com.

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