Mammals

Koala populations in Australia are in decline, in part due to the ravages of chlamydia, a sexually transmitted bacterial infection.

By Carrie Tatro

It pays to be brainy when you're a ring-tailed lemur.

By Jesslyn Shields

The platypus may look a bit absurd and bizarre, but its milk might hold the secret to fighting antibiotic-resistant bacteria.

By Jesslyn Shields

Nutria are jumbo-sized rodents that reproduce and eat at a jumbo-sized pace.

By Jesslyn Shields

Urban coyotes have a fierce and formidable reputation as midnight predators, but coexistence with humans is possible.

By Carrie Tatro

Some people mistakenly believe that if chimps are socialized from an early age, they're not a threat to humans. But these five families found out the hard way that chimps will always be chimps.

By Nathan Chandler

Why do squirrels exhibit behavior that can get them killed by cars? And how can you avoid them?

By Jamie Allen

The first new rat species found in the Solomon Islands in 80 years has been uncovered. But due to deforestation of its habitat, very few may still exist.

By Jesslyn Shields

Fall is in full swing and that means squirrels are busy hoarding nuts for winter. So how do they remember where they buried them? Research suggests they use mnemonic strategies.

By Jamie Allen

Due to a quirk in their anatomy, injured hedgehogs can experience skin inflating to the size of a basketball, which can be a painful and life-threatening development.

By Laurie L. Dove

Thanks to the excesses of narcoterrorist Pablo Escobar, Colombian waterways now house a population of these invasive African giants.

By Jesslyn Shields

Sure, these mammals may be cute and cuddly. But that doesn't mean their bite can't pack a punch.

By Kate Kershner

By frightening top predators, the fear of humans may be distorting ecosystem processes even more than previously imagined.

By Jesslyn Shields

A new scientific study reveals that the smells unique to meerkat communities aren't produced by the meerkats themselves.

By Chris Opfer

A new genetic analysis clarifies the evolutionary relationships between five modern and extinct elephant species.

By Jesslyn Shields

Despite our best efforts at eradicating them, rats keep outsmarting us. Here's how.

By Melanie Radzicki McManus

We've learned that young orangutans nurse for much longer than any other mammal, knowledge which could help conservation efforts.

By Jesslyn Shields

It's the first evidence researchers have of the whales using their "unicorn horns" to capture prey.

By Kate Kershner

Deprived of oxygen, naked mole rats can alter their metabolic functions to something less mammalian and more plantlike, burning fructose instead of glucose.

By Jesslyn Shields

It's like the movie "Groundhog Day" every April, but with hibernation, a smaller rodent and way more hormones.

By Jesslyn Shields

Rhino herds defecate in giant, shared dung piles called midden, then they stick their noses in the stuff. Here's why.

By Jesslyn Shields

The feral pig population in the U.S. is a growing issue in nearly 40 states. The USDA hopes to wipe out the billion-dollar problem within a decade.

By Melanie Radzicki McManus

House cats seem to love chasing laser pointers. But what about their larger, wilder cousins?

By Laurie L. Dove

If you look outside your window right now, you'll probably see one running up a tree or checking you out. How did the squirrel get so commonplace?

By Kathryn Whitbourne

Ring-tailed lemurs - perhaps the most iconic species on the tropical island of Madagascar - are in significant decline due to habitat loss, hunting and illegal capture.

By Patrick J. Kiger