Remarkable Rodents From Capybaras to Flying Squirrels

Eyes, ears, and nostrils sit high on the capybara’s head. Watch one sink low in the water and you can see how much of the body can disappear while the parts it uses to look, listen, and breathe stay above the surface. This South American grazer can also use water to escape danger.

A fold of furred skin stretches from wrist to ankle when this squirrel launches between trees. Its flattened tail helps with steering in flight and landing. The membrane is easiest to see in a photo taken just before touchdown, when the squirrel is still spread wide.

Notice where the lips close. The large front teeth sit outside them, ready to bite soil without filling the mouth. A naked mole-rat can use those same teeth to pick up and shift bits of earth. The teeth are digging tools and a way to handle what gets in the way.

The long legs make the mara look more like a small hoofed animal than a rodent. Its social life is just as distinctive. Adults commonly live in pairs, but converge at a communal warren to raise their young. Pups can emerge while adults are nearby, then duck back into a shelter shared with other families.

In one Mojave Desert field study, Merriam’s kangaroo rats went without drinking even when rainwater was temporarily available. They obtained more water than the researchers expected from a dry seed diet alone. The finding leaves a more interesting question than whether they can go without a drink: where the extra water comes from.

The beaver can grip a branch with its incisors while its lips close behind the teeth. That seal helps it carry food or wood in water. A transparent membrane also shields each eye when it dives. Compare this use of the front teeth with the naked mole-rat’s way of digging without swallowing dirt.

This porcupine carries a rattle at the end of its short tail. Special hollow quills knock together when shaken, an audible warning alongside the display of raised quills. If the warning fails, it can back toward a threat with the pointed quills on its back raised.

The long hind feet of the lesser Egyptian jerboa each have just three toes. A tail ending in a pale brush trails its small body. Compare that silhouette with a kangaroo rat’s, then look at the feet to see the form a desert hopper takes in northern Africa.

An agouti can bury a palm seed, and another agouti can dig it up and hide it somewhere else. Researchers followed radio-tagged palm seeds through these repeated moves on Panama’s Barro Colorado Island. Some seeds escaped being eaten after all the shuffling, even when their long trip was made up of a series of short ones.

A springhare looks different under ultraviolet light. With the right viewing filter, patches of the South African species’ fur fluoresce orange to red. Researchers documented the glow under controlled illumination, which leaves an open question about the role it might have under natural conditions.

Large cheek pockets let this rodent carry food while leaving the jaws free. That is the feature behind its name. The southern giant pouched rat is also the species documented by APOPO for its trained scent-detection animals, which brings a different adaptation into view.

The rows of pale spots are easy to see on a lowland paca. The feature you can’t see is inside the skull. Broad cheek arches and hollowed areas in the surrounding bone form a chamber associated with resonance, an unusual structure for a rodent with such a stout outline.

A colony of plains viscachas can share an underground network of passages and chambers for generations. In the Argentine Pampas, researchers examined the remains of prey left by burrowing owls at an entrance excavated by viscachas. There’s more to learn from an entrance than which rodent dug it.

In Chile, wild long-tailed chinchillas use holes and crevices in rocky country and come out at night. The dense fur is easy to notice, but the animal’s longer tail and ears also help distinguish it from the short-tailed chinchilla. Those features are especially clear in profile.