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Mammals

Large whales can get wrapped up in fishing lines, buoys, nets and other gear, which can lead to injuries and death.

U.S. Whale Entanglements Are on the Rise, New Data Shows

The National Oceanic and Atmospheric Administration confirmed 95 large whale entanglement cases last year, a 48 percent increase from 2023

Bear 32, nicknamed Chunk, was crowned the 2025 Fat Bear Week champion.

After Two Years as Runner-Up, Chunk Is Finally Crowned Winner of Fat Bear Week

The brown bear heavyweight persevered through a jaw injury this year that will permanently hinder his ability to fight and hunt

Jane Goodall visiting a chimpanzee rescue center in 2018 in Entebbe, Uganda

Jane Goodall, Legendary Primatologist and Anthropologist, Dies at 91

She was considered the world’s leading expert on chimpanzees and was renowned for her global conservation efforts

An 1844 illustration of mink

The Life, Loss and Lore of the Sea Mink

It might be among the first mammals to go extinct in North America after colonization. But can scientists prove it was even a distinct species?

The orca known as “Old Thom” swims in front of researchers in the Bay of Fundy.

The Curious Case of ‘Old Thom,’ an Orca Traveling Alone in the North Atlantic

Sightings of the marine mammal captivate the public and baffle scientists

A jaguar, not the one documented in the new study, swims in the Pantanal in Brazil.

A Jaguar in Brazil Makes the Longest Recorded Swim by the Species, Traversing at Least 0.79 Miles Through Water

The new record could help conservationists strategize ways to consider feline movements during construction of hydroelectric dams

Moms and dads of just about every species can relate to this image of a cub climbing on its parent’s back.

Smithsonian Photo Contest Galleries

Behold These 15 Photographs of Big, Beautiful Bears

Get an up-close look at these massive mammals … from a safe distance

Many rodents have nails on their thumbs and claws on the rest of their fingers. A new study suggests this trait might have been key to their world domination.

Rodents Conquered the World With the Help of Their Thumbnails, Study Suggests

The trait might have given rodents greater manual dexterity, allowing them to access new foods, such as nuts

Researchers studied genetic samples from 483 mammoths, including from their tusks, bones, skin and molars (shown here).

Scientists Investigate the Bacteria That Colonized Extinct Mammoths—and Uncover the Oldest Known Microbial DNA From a Host

Some of the microbes might have been benign or helpful, while others could have caused deadly diseases

Many different types of animals, from birds to orcas, are affected by human noise.

Five Dramatic Ways Animals Respond to Human Noise, From Mimicking Car Alarms While Wooing Mates to Calling Higher Over the Din of Traffic

As human-caused sound gets louder around the world, some animals change their behavior and many creatures suffer health issues

An aardvark emerges from its burrow.

Could Aardvark Burrows Be Ground Zero for the Next Pandemic?

Animals of all kinds mix and mingle in the underground refuges, offering troubling opportunities for diseases to jump species

Yagi (left) and Quinn (right) are searching for evidence of critically endangered Sumatran rhinos in Indonesia's Way Kambas National Park.

Two Sniffer Dogs Might Have Just Found a Lost Population of Critically Endangered Rhinos

Yagi and Quinn identified scat that was likely left by a Sumatran rhinoceros in Indonesia’s Way Kambas National Park, where scientists thought the animals had disappeared

Bison graze near the north entrance of Yellowstone National Park in Gardiner, Montana.

Restoring Bison to Yellowstone Has ‘Reawakened’ the Ecosystem as the Large Animals Migrate, Study Suggests

An analysis of plant diversity and soil health across the bison migration corridor suggests free-roaming bison lead to more nutrient-rich plants

Researchers often observed a family of bats roosting together in tight "cuddle balls."

These Big, Meat-Eating Bats Also Have a Cuddly Side. Rare Videos Reveal ‘Hugging,’ Playing and Sharing Food

Scientists observed a family of four spectral bats in their roost in a tree in Costa Rica, capturing an inside look at their social behavior

Early whales walked on land and swam in the shallows to hunt.

Before Whales Took to the Sea, These Ten Species Walked on Land

The creatures, which ranged in size from that of a fox to more than 50 feet long, divided their time between the coast and the water

This rabbit's "horns" are made of keratin, which is also found in hair and nails.

Rabbits With ‘Horns’ Seen in Colorado Are Going Viral. Here’s What’s Really Happening

Though the strange growths on these animals may look intimidating, experts say there’s not much to worry about, and they’re caused by a fairly common virus

Novaculadon mirabilis is characterized by its razor-sharp teeth.

A Student Spotted a Jawbone at a Beach. It Turned Out to Be a New, Mouse-Sized Mammal That Lived Among Dinosaurs

The species was named for its pointy teeth and could shed light on early mammal adaptations

An illustration of a mother and calf Janjucetus dullardi, a newly discovered tiny whale species with a sharp bite

Cool Finds

Newly Discovered Prehistoric Whale Is ‘Deceptively Cute’—It’s Tiny but Has a Mouth Full of Razor-Sharp Teeth

Found on the southern coast of Australia, the species could fill gaps in scientists’ understanding of baleen whale evolution

Several species have evolved in response to human environmental impacts.

Five Astounding Ways Humans Are Driving Animal Evolution, Including Causing Lizards to Grow Longer Legs and Leading Moth Populations to Become Darker

When people build cities and introduce invasive creatures, resident critter populations sometimes adapt

Artist illustration of a pack of Borophagus secundus

What Happened to the Bone-Crushing Dogs That Once Hunted Across North America?

Before going extinct roughly two million years ago, canids known as borophagines took down and consumed much larger prey

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