Mammal gamble

The world's most comprehensive study of mammals in the wild reveals that at least a quarter of species risk extinction. A staggering 79 percent of apes and monkeys in regions of Asia, for instance, face such danger. But while this study may be alarming, it need not come across like an alarmist.

True, hundreds of mammal species could disappear "within our lifetime," according to Julia Marton-Lefèvre, director general of the Geneva-based International Union for Conservation of Nature (IUCN), which last week released a study of 5,487 species identified since 1500.

In the intervening centuries, 76 mammal species have become extinct, according to IUCN estimates. But the stepped-up pace of habitat loss (through human settlement, logging, and agriculture) – plus overhunting, overfishing, and pollution – are accelerating the decline among a swath of species, from hippos to bears to tapirs. Regions of Asia, Africa, and South America are especially affected.

Complicating the picture are the unknown effects of climate change on land and ocean habitat. Will species adapt? Or will global warming simply prove too much for some?

And yet, extinction is not inevitable. At least 5 percent of the IUCN's currently "threatened" species now have stable or rising populations – the result of conservation efforts. African elephants are rebounding, for instance. In the United States, the black-footed ferret has become a poster animal for successful intervention and cooperation between government and scientists.

A species that was essentially extinct in the North American prairies by 1996, the ferret has moved up to "endangered" after a successful reintroduction effort by the US Fish and Wildlife Service in eight Western states and Mexico.

Recovering mammals act as signposts for the way ahead. For instance, legal protections – of lands, waters, and species – have been critical to stopping or turning around a dangerous decline in mammal populations. International measures such as the whaling bans and the Convention on International Trade in Endangered Species have also helped.

So have the evolving skills of scientists. As human needs and wants have increasingly clashed with other mammals' needs, scientists have buttressed moral arguments for conservation with practical ones.

Increasingly, they've earned degrees in economics and sociology, so that they can explain that species deserve a chance at survival not only for their own sake, but for the sake of humans, too. Humans depend on bats to pollinate, on field and forest rodents to distribute seeds, and so on.

The conservation movement in general has learned it's not enough to fight human encroachment. It has to work with development – for instance, by providing corridors for migrating mammals.

Ahead lies another great challenge: how to move from a reactionary stance to a global prevention plan. One encouraging step is last month's pledge by the United Nations to "significantly reduce the rate of biodiversity loss by 2010."

The IUCN's immense database is essential to reaching this target. Just as the Dow Jones Industrial Average tracks stocks, or the No Child Left Behind Act does the same for reading and writing, the world now has a very useful tool to measure progress or setbacks with the world's mammals.