A non-native species of tortoise is proving a good substitute for extinct native seed dispersers in Mauritius.
Some animals and plants that reproduce asexually "can in principle achieve essentially eternal life," according to a new study.
Some have populations numbering less than five individuals.
Exxon, Shell, Gazprom, BP and Rosneft are together planning an oil rig off the coast of Russia -- a move that could harm an already critically endangered whale species.
A whistling frog named after Wolfgang Amadeus Mozart and an elusive ventriloquist frog are found in Haiti.
Toxic waters could have even been the norm through much of the planet's history.
A biodiversity crisis as a result of invasive species may have capped the Devonian - not a mass extinction event.
The "prizzly" bear and other animal hybrids could lead to extinctions.
A map of tiger habitat in Sumatra reveals the island may hold the second largest population in the world, giving hope to conservationists.
Polar bears may be at a disadvantage when competing with their close relative, the brown bear.