Mammals

An artistic rendering of a multituberculate mother with her litter of offspring.

Just Like Us, Jurassic Mammals Cared for Their Young

Clues from bones reveal multituberculates looked after their offspring for lengthy periods during the Age of Dinosaurs

A mountain lion, P-22, known to live in the Los Angeles area

L.A.'s Cougars Were Driven to Extremes by Wildfire

With less suitable habitat, the big cats traveled further and crossed dangerous roads more often

The eastern lowland gorilla saw an estimated 80 percent decline in the Democratic Republic of the Congo’s Kahuzi-Biega National Park between 1994 and 2019. 

Animal Populations Faced a ‘Very Sharp Decline’ Since 1970

World Wildlife Fund researchers say vertebrate populations decreased by 69 percent, on average

Two juvenile gray wolves in Washington

Six Endangered Gray Wolves Were Poisoned in Washington

Conservation groups are offering more than $51,000 for information on the killings

The Mirage dolphin exhibit in 2000

Three Dolphins Die at the Mirage in Six Months

The Las Vegas hotel and casino temporarily closed its dolphin exhibit after 11-year-old K2 passed last month

Bison typically roam the tall grasses of the American prairie, but a herd in Grand Canyon National Park has found ways to thrive in forest and desert habitats.

Meet the ‘Forest Ninja Bison’ Living in Grand Canyon National Park

Wildlife managers recently relocated dozens of the iconic animals to help restore balance to the park's ecosystem

A bull walks in front of a cow. If they mate, the bull’s sperm will likely cluster together as they swim through the female’s reproductive organs.

Bull Sperm Get by With a Little Help From Their Friends

Traveling together helps the sperm navigate a tricky, sticky migration through a cow's reproductive tract

One reader wonders: Why did ants make it all over the Americas while anteaters didn’t?  

Why Do Anteaters Live Only in the Tropics and More Questions From Our Readers

You've got questions. We've got experts.

Calli moves around on land.

Beloved Sea Lion at National Zoo Dies Unexpectedly

Calli, a 17-year-old California sea lion, is remembered by zoo staff as a good mother and ambassador for her species

A male bison atop an arid hillside on Santa Catalina Island in California.

The Uneasy Future of Catalina Island's Wild Bison

One of Hollywood’s weirdest legacies, the herd of beasts lives under the watchful eye of local conservationists

Hoffmann’s two-toed sloth babies need round-theclock care. Once they’re adults, they’ll be microchipped and released back into the rainforest.

Baby Sloths Are About as Cute As You Would Expect

A Costa Rica rescue center offers blankets and bottle-feeding at a nursery for these young animals

A polar bear mom and cub wander near the quarry on the outskirts of Churchill. 

As Arctic Temperatures Rise, Polar Bears Are Eating More Garbage

A new paper warns that a growing reliance on trash is leading to more human-bear conflict

Over the past decade, vaquita numbers plummeted from 576 to just ten individuals because of a rise in the illegal totoaba trade.

The Population of Vaquita Porpoises Has Dwindled to Ten, but a Rebound Isn't Out of the Question

If protected from illegal fishing, scientists say the critically endangered species has enough genetic diversity to recover

A Tuatara in New Zealand

One in Five Reptiles Worldwide Are Threatened With Extinction

Researchers assessed over 10,000 species in a comprehensive new study

Researchers are most concerned with the disease affecting endangered species like these riparian bush rabbits.

New Vaccine Could Save Rabbits From Deadly Hemorrhagic Disease

Scientists have a new tool in the fight against a spreading virus that threatens the small mammals

Visible in the entrance to their den are a mother black bear, who has been sedated, and her female cub. Scientists are watching to see how bears will tweak their hibernation habits as the climate warms.

Why Amazing Discoveries About Bear Hibernation May Help Improve Human Health

The creatures' annual protracted snoozes have much to tell us about the biology of mammals, ourselves included

The cat-sized, butter-colored rodents live about 15 years on average, a much longer lifespan than what is expected for their size.

Yellow-Bellied Marmot Hibernation Could Unlock the Key to Longevity

The fluffy rodents stop aging when they curl up in their dens for winter and start again once they emerge in spring

A captured fisher is released after undergoing sedation and physical examination, a part of the Hoopa Valley Tribe’s longstanding efforts to monitor the culturally important species.

Inside the Hoopa Valley Tribe's Quest to Understand a Rare Carnivore

The tribe maintains some of the most detailed documentation of fishers in North America

A feral fox in Australia.

Cats and Foxes Kill 2.6 Billion Animals Per Year in Australia

A new study is the first to quantify the impact the two non-native predators have on local wildlife in the country

A fossil of a Diegoaelurus jawbone was recovered from a construction site in Oceanside, California.

Paleontologists Uncover the Oldest Sabertoothed Predator

Fossil jaw shows earliest evidence of a specialized carnivore with scimitar-shaped fangs

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