The Failure to Halt the Extinction Crisis

One of the Wildlife Conservation Society's 'Rarest of the Rare,' the addax is suffering from desertification in Africa, induced by farming and development, as well as climate change. The United Nations has estimated that as many as one in four mammals on Earth is threatened with extinction.

The full accounting of the 'rarest of the rare' is available in the WCS publication State of the Wild.

The Abbot's booby, one of the 'rarest of the rare,' is threatened in its Easter Island habitat by an invasion of yellow crazy ants. Invasive species (those transported from one continent or habitat to another, where they compete with native species) are sometimes called biological pollution, and they are among the biggest causes of biodiversity loss worldwide.

Some estimates predict as many as 10 bird species will go extinct every year if current rates of habitat loss, pesticide use and other factors continue.

The World Conservation Union's Red List of endangered species stands at 16,306, including the pygmy hippo, one of the WCS 'rarest of the rare.' The status of most species, however, has never been assessed. The biggest threat to the West African mammal is habitat loss from deforestation. The world has lost a forest the size of the United States in the past century.

The greatest threats to the snow leopards today include poaching for their pelts and body parts, loss of habitat, increased conflict with humans and livestock, and dwindling populations of the wild sheep and wild goats that are their main prey.

The 12 Asian nations that have territory in snow leopard habitat have met in an effort to stop the big cat's slow march toward extinction.

Around the world, big cats are imperiled. Just 6% of the world's tigers remain, and 40% of lions.

The polar bear has received the most attention relative to the plight of endangered species in the Arctic, but many other mammals, like the Pacific walrus, are believed to be threatened by the loss of sea ice as well.

Global warming will make many species endangered, as heat-intolerant species struggle to find suitable habitat, new diseases spread and the ecology of vast regions changes.

The radiated tortoise, seen here in Tsimanampetsotsa National Park, is one of Madagascar's five critically endangered tortoises. Four other turtles and tortoises are in decline. Like much of Madagascar's wildlife, radiated tortoises live nowhere else.

Biodiversity hotspots like Madagascar are increasingly the focus of conservation, as the world tries to halt an extinction crisis that scientists believe is the first in the geologic record to be caused by one species, humans.

You can help.

See these 10 Easy Things You Can Do At Home To Help Endangered Species