Health & Safety

It's not easy to track down one of the fastest and rarest great cats in the world. But one biologist is working to attach radio collars to cheetahs living in remote areas of Iran. With fewer than 100 of the animals left, they are among the most imperiled great cats on Earth.

Snow leopards are among the world's most endangered big cats, with only several thousand left. In Mongolia's southern Gobi desert, the snow leopard is a sign of a healthy ecosytem. But poaching remains one of the area's more lucrative businesses.

Snow leopards are among the world's most endangered big cats, with only several thousand left. In Mongolia's southern Gobi desert, the snow leopard is a sign of a healthy ecosytem. But poaching remains one of the area's more lucrative businesses.

A settlement once home to hundreds has been unearthed near England's Stonehenge. Archaeologists think the builders of the huge stone circle may have lived in the village. It dates to the same time period.

A settlement once home to hundreds has been unearthed near England's Stonehenge. Archaeologists think the builders of the huge stone circle may have lived in the village. It dates to the same time period.

In literature, albatrosses represent weighty, inescapable burdens. But in real life, the huge seabirds use wind energy to cruise around the planet's oceans. Photographer Frans Lanting and writer Carl Safina report from one of the world's largest albatross colonies.

In literature, albatrosses represent weighty, inescapable burdens. But in real life, the huge seabirds use wind energy to cruise around the planet's oceans. Photographer Frans Lanting and writer Carl Safina report from one of the world's largest albatross colonies.

Running underneath the rolling hills of Tennessee lies a still-mysterious and remote network of caverns. Many of those caves shelter fragile ecosystems, and biologist Jerry Lewis is helping to discover and protect some of those ecosystems from man's destruction.

Running underneath the rolling hills of Tennessee lies a still-mysterious and remote network of caverns. Many of those caves shelter fragile ecosystems, and biologist Jerry Lewis is helping to discover and protect some of those ecosystems from man's destruction.

Conservationist Bruce Beehler is pushing through a wild and previously unexplored jungle in search of a mysterious and poisonous bird native to Papua New Guinea, the pitohui. His only lead and guide is a local shaman, who uses poison from the bird in his rituals.