• <menu id="sw444"><strong id="sw444"></strong></menu>
    <nav id="sw444"><code id="sw444"></code></nav>

    The National Wildlife Federation

    Donate Donate


    Mammals—a group that include humans—are warm-blooded animals with hair and vertebrates, or backbones. Unlike other classes of animals, female mammals produce milk to nourish their young. Almost all mammals give birth to live young (except for the platypus and echidna, which lay eggs).

    Scientists have identified more than 5,400 mammal species on Earth, roughly one-fifth of which are known to be threatened or extinct. One of the most threatened order of mammals is the primate, which includes monkeys and apes. The United States has more than 400 mammal species. Of those mammals, nearly a quarter are listed on the U.S. endangered species list for reasons including habitat loss, climate change, pollution, and disease.

    Bat Image


    Nocturnal, flying mammals that eat fruits and insects

    Bats Indiana Bat
    Jamaican Fruit-Eating Bat Little Brown Bat
    Flying Squirrel


    Gnawing mammals with a single pair of incisors

    American Beaver Black-Tailed Prairie Dog
    Dusky-Footed Woodrat Flying Squirrels
    Pocket Gophers Red Squirrel
    Red Tree Vole
    American Pika


    Gnawing mammals with two pairs of incisors

    American Pika Snowshoe Hare
    Swamp Rabbit
    Nine Banded Armadillo

    Moles and Armadillos

    Burrowing mammals

    Moles Nine-Banded Armadillo

    Get Involved

    Where We Work

    More than one-third of U.S. fish and wildlife species are at risk of extinction in the coming decades. We're on the ground in seven regions across the country, collaborating with 53 state and territory affiliates to reverse the crisis and ensure wildlife thrive.

    Learn More
    Regional Centers and Affiliates
    Get Back to Nature. Search, discover, and learn about wildlife. Anywhere, anytime. Nature Guides. Now available!