In the Potomac River scientists and anglers have uncovered male smallmouth bass growing eggs. The reason is a mystery, but clues point to estrogen-enhanced sewage.

Deep beneath the Antarctic ice sheets are at least 145 lakes that may be teeming with microscopic organisms similar to those that could be thriving beneath the ice on Jupiter's moon Europa.

Every October or November the reproductive swarming of an ocean worm known as the palolo is cause for a Samoan celebration. Fried in oil, baked into bread, or swallowed raw, worm sperm and eggs are a seasonal delicacy here.

For the first time in nearly a half century, puffins are returning to Ailsa Craig. The Scottish island is already well-known in the sport of curling as the world's best source of curling stones.

One of the rarest snakes in the U.S., the Louisiana pine snake is relatively abundant on a tract of commercial forest in the state. Scientists hope to learn why.

A politically charged program to poison prairie dogs has begun in South Dakota. Mixed in with the controversy is an endangered ferret and the rights of cattle ranchers.

Birder Mathew Tekulsky recalls how American robins and other species visited his California yard for a few weeks in January, when a pyracantha bush produced its ripe berries.

A 121-million-year-old fossil of an unhatched bird has been found in China. The fossil suggests early bird species, like dinosaurs, were well developed at birth, scientists say.

The decline of domesticated bees threatens North America's food supply. Some researchers believe original wild bee species could come to the rescue.

To appreciate the pleasures of beekeeping, just listen to a hobbyist beekeeper from Walnut Creek, California, buzz about the insects in her hive.

Great white sharks are among many endangered species to gain better international protection at a meeting of 166 countries in Thailand. Restrictions on black rhinos were eased.

A tiny fish that no one eats or cares about may tell researchers a lot about the health of Caribbean coral reefs and where to focus conservation efforts.

Paleontologists say they have discovered the fossil remains of a duck-size dinosaur species, previously unknown to science, that died while catching some z's.

For centuries the Tsaatan people have roamed Mongolia with the reindeer that provide their livelihood. But disease and inbreeding now threaten their herds—and cultural future. With photo gallery.

Like the woolly mammoth, a giant, prehistoric deer survived the last ice age, a new study shows. So what caused the Irish elk's eventual extinction?