Q: How many animals have gone extinct due to human causes?

Adikan Wiering

Grade 6

Sennett Middle School

Stanley Temple, a professor of wildlife ecology at UW-Madison, says 83 mammals, 151 birds, 22 reptiles, 35 amphibians and 93 fish have definitely gone extinct since 1500.

All of these extinctions involved the human hand, Temple says. The causes include over-exploitation, loss of habitat, pollution and the introduction of exotic species. In Lake Michigan, Temple says, four species of whitefish have gone extinct within the last century.

But the tally of proven extinctions is always an underestimate, Temple said. Some species go extinct before they become known to science, and others may have disappeared so recently that their status cannot be known for sure.

Furthermore, the vast habitat changes that global warming will cause have not yet affected extinction numbers. Some scientists, Temple says, "believe that most of the world's endangered species are likely to go," including about 20 percent of the world's bird species.

Temple stresses the utility of many wild species: Birds eat insects; bees pollinate crops; fish provide food; trees provide wood and fiber; yeast make wine and beer. But he says the species sharing our planet also deserve protection for ethical reasons.

"Many environmental problems can be corrected, but with extinction, the damage is irreversible, and that should be of great concern as it means future generations will inherit an impoverished world from us," says Temple.

Produced in cooperation with University Communications

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