The chambered, or pearly, nautilus (Nautilus pompilius) is a charismatic cephalopod species known for its exceptional spiraling, chambered shell. It belongs to a family that has barely changed since ...

Bluefin tuna are an ocean-going fish that grow up to 10 feet long and can weigh as much as 1,200 pounds. Unlike almost all fish, bluefin tuna are warm-blooded and able to regulate their body ...

DESCRIPTION: Walruses are easily distinguished by their long, white tusks, cinnamon-brown skin, grizzled whiskers, and bodies full of blubber. Growing up to 3,750 pounds, male Pacific walruses are ...

Oases in the desert, Southwestern streams are among the most delicate ecosystems on the planet. In these shallow, ephemeral waters, species like the Mexican garter snake once carved out a precarious ...

Why are bats dying in North America? An estimated 6.7 million bats have died since 2006 because of an outbreak of white-nose syndrome, a fast-moving disease that has wiped out entire colonies and left ...

Three vital provisions give the Act its teeth. It’s “citizen-suit” provision lets public-interest groups and individuals petition and sue sluggish federal agencies to make sure the Act protects ...

The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems. Biological diversity, often shortened to biodiversity, is ...

The U.S. transportation sector is responsible for about a third of our country’s climate-damaging emissions. In California transportation is the leading source of greenhouse gas pollution, accounting ...

The American pika — a small, herbivorous, conspicuously cute mammal related to rabbits and hares — is adapted to the cold climate in high-elevation boulder fields and alpine meadows in the mountains ...

As this keystone species' name suggests, the gopher tortoise is an expert at living underground — like a gopher. Gopher tortoises have shovel-like front legs and strong, thick back legs to help them ...

DESCRIPTION: Female bald eagles can weigh up to 14 pounds and have wingspans of eight feet. Males weigh up to 10 pounds, with wingspans of six feet. Both sexes have brown bodies and acquire their ...

For every county in the United States, the map below shows information on all the animals and plants protected under the U.S. Endangered Species Act as threatened or endangered. To see the number of ...