This 2-foot-long, black-masked member of the weasel family once occurred in central grasslands and basins from southern Canada to Texas but is now one of the most endangered mammals in North America.

Plastic bags start out as fossil fuels and end up as deadly waste in landfills and the ocean. Birds often mistake shredded plastic bags for food, filling their stomachs with toxic debris. For hungry ...

Our planet now faces a global extinction crisis never witnessed by humankind. Scientists predict that more than 1 million species are on track for extinction in the coming decades. But there’s still ...

The United States has an amazing and diverse array of native bees. Across the country live about 4,000 native bee species — most of which are solitary and nest in the ground — coming in nearly every ...

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 ...

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 ...

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 ...

Monarch butterflies are important culturally and ecologically across North America. Generations have watched in wonder as yellow-and-black striped caterpillars fold into green-and-gold chrysalises and ...

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 ...

The grizzly bear is so named because its hair is grizzled, or silver tipped, yet the name is commonly believed to be derived from “grisly,” meaning “horrible.” DESCRIPTION: A subspecies of brown bear, ...

The word jaguar comes from the South American Tupi and Guarani languages. A likely origin is the word yaguareté, meaning “true, fierce beast.” DESCRIPTION: The largest cat native to North America and ...

DESCRIPTION: Roughly five feet in length, Mexican gray wolves generally weigh between 50 and 80 pounds. Their coats are buff, gray, and rust colored, often with distinguishing facial patterns. They ...