Despite the fact that we lose species every year on this planet, there are still a bunch of them most people have never heard of. Take, for instance, the jerboa. If there weren't a photo of one of these weird little animals at the top of this article, it's possible you'd be hard-pressed to conjure a picture of one in your mind.
The Hard Life of a Desert Rodent
But a jerboa is a small, nocturnal rodent, with a pig-like snout, a long tail like a Dr. Seuss character and inexpressibly delicate hind legs and stumpy little arms like Tyrannosaurus rex — its arms are so short they can't reach the top of its head. Jerboas are native to some of the hottest deserts in the world, in North Africa, the Arabian Peninsula and Asia, where they primarily feed on roots and seeds, but some species also eat insects.
"Jerboas compete for resources — food and shelter — with gerbils, but they tend to avoid conflict by foraging in different habitats," says Talia Y. Moore of the Robotics Institute at the University of Michigan, Ann Arbor, who studies the biomechanics of jerboa locomotion, their behavioral ecology, and evolution. "Jerboas and gerbils are also prey to large desert predators, like birds of prey, snakes and fennec foxes. Some historical accounts also describe humans catching and eating jerboas!"
Because they live in the desert, jerboas have evolved ways to conserve water in their bodies. For starters, they don't drink any free-standing water — they get every bit of it from their food.
Secondly, they barely urinate at all, which is partly why they don't smell as bad as some other rodents you might have as pets.
Jerboas Make Terrible Pets
However, jerboas have been banned as pets in the United States since 2003 due to their association with an infectious disease called monkeypox, which can infect humans. They can be kept in the U.S. only under special circumstances (like for research purposes), but if you live in Germany and want a jerboa as a pet, you're in luck! They are totally allowed there.
Jerboas are bipedal (meaning they get around on two legs) members of the superfamily Dipodoidea, which includes 51 species, 33 of which are jerboas — the other 18 include quadrupedal birch mice and meadow jumping mice, which can use either their two back legs for locomotion or all four.
Jerboas move very much like kangaroos, hopping around on their hind legs and steadying themselves with their tails when sitting upright. When chased, a jerboa can escape a predator at around 16 miles per hour (26 kilometers per hour).
They're High Jumpers
"Because jerboas are prey animals, they have evolved amazing escape behaviors that include jumping over 10 times hip height — that would be like us jumping over an Olympic high-dive platform — and their locomotion is really unpredictable," says Moore, in an email. "Being bipedal makes them better at escaping predators than their gerbil neighbors, so jerboas can forage in open areas where they are more likely to be seen by predators, and gerbils can forage near bushes where they are less likely to be seen."
According to Moore, one fascinating thing about jerboas that you might see in a drawing or taxidermied in a natural history museum is that they are incorrect!
"They show them totally stretched out and looking up, which they only do when they're curious about something up high," says Moore. "Most of the time, they are totally horizontal, with their hip as the highest point of their body. Using CT scans and high-speed X-ray videography, my colleagues and I drew the first posturally accurate reconstruction of their skeleton to help inform future museum specimen preparers."