Free-roaming chickens in Key West, Florida, have many residents crying "fowl" over concerns about avian flu.

Arbor Day reminds us of the beauty and utility of trees. But in New Orleans historic species have been ravaged by Hurricane Katrina, changing the city's leafy landscape.

The world's deepest dinosaur fossil has been discovered off Norway almost one and a half miles beneath the seabed.

Strict isolation of households and stiff travel restrictions are among the tactics touted by scientists in a new study of how to combat a pandemic.

Two decades after a nuclear-plant explosion blanketed the area in radiation, residents of the former Soviet region still battle the aftermath of abandoned homes and shattered lives.

MRSA, a penicillin-resistant strain of S. aureus common in hospitals, is showing up in gyms, day care centers, and other group settings.

Giant tortoises might have survived a lava flow in the past, but today conservationists prefer not to take chances. Watch as some of the rare reptiles are airlifted out of reach of an erupting volcano.

The April 21 earthquake was as strong as the 1906 San Francisco temblor but killed no one. Though fairly common, most big quakes occur out of harm's way, experts say.

The deadly bird flu may arrive in the U.S. and elsewhere via migrating birds. The key is just to keep them away from poultry, researchers say.

Earth Day meets the 21st century: Environmental and other scientists should embrace blogs as potentially potent tools for advancing science and policy, experts recommend.

Antiviral drugs can immobilize a virus, but mathematical models of viral pandemics show that if too many people pop the pills, the virus is likely to regain the upper hand.

Earth's climate may still warm up by several degrees in response to greenhouse gas pollution, but it may not be as sensitive as some scientists have feared, a new study says.

Deep beneath the ice sheet, massive volumes of water and life-forms may be gushing from lake to lake, scientists say.

One of the world's most active but least known volcanoes is threatening a wave of destruction on the densely populated Indonesian island of Java.

As oil prices hit record highs, scientists have unveiled a technology that can turn coal, natural gas, and biomass into a fuel that burns cleaner than gasoline.