How will we live without them? A quarter of the world's mammals may be headed toward extinction.

• Author: Klinkenborg, Verlyn
• Position: OPINION - Essay

Like most people, I've been looking at the numbers that measure the convulsions in the global financial markets. And as I do, I think about another frightening set of numbers--the ones that gauge the precipitous declines in the species that surround us. The financial markets will eventually come back, but not the species we are squandering.

The International Union for the Conservation of Nature in Barcelona, Spain, recently re[eased results of a global survey of mammal populations. It concluded that at least a quarter of mammal species are headed toward extinction in the near future. The first ones to go will be primates: Nearly 80 percent of the primate species in southern and southeastern Asia are immediately threatened.

The causes are almost all directly related to human activity. For example, the African elephant is threatened by the destruction of their habitat by land developers. Even in protected areas, elephants are kilted by poachers who illegally harvest their tusks for the ivory trade.

The numbers are not much better for other categories of life. At least 22 percent of reptile species are at risk of extinction. In Europe, 45 percent of the most common bird species are rapidly declining in numbers, and so are those in North America.

NATURE'S RESILIENCE

These numbers are shocking, but they don't tell the whole story. They are projections for the most familiar, most easily counted plants and animals--less than 4 percent of the species on Earth. It is reasonable to assume that many of the uncounted species are doing as poorly.

Everything is connected. No species goes down on its own, not without...