Learn About Chevrotains, the Smallest Hoofed Mammals on Earth

Imagine an animal that seems to be assembled from various other creatures: it has large eyes, the round body of a rabbit, a rodent’s pointed snout, tiny pig-like hooves, and even fangs like those of a saber-toothed tiger. This strange mashup is the chevrotain, a quirky animal that continues to puzzle scientists with its unusual combination of features. As you can see in this YouTube video, this tiny creature is one of the world’s most intriguing — and elusive — animals.

An Unconventional, Ancient Animal

The name “chevrotain” is actually quite descriptive. It comes from French and means “kid,” “fawn,” or “goat,” which hints at the animal’s unique appearance, even though it isn’t any of those animals. You might also hear it called a “mouse-deer,” but again, it’s neither a mouse nor a deer. So, what exactly are chevrotains? They belong to a unique family called Tragulidae, which sets them apart from other hoofed mammals. These animals represent an evolutionary link between animals with simple stomachs, such as pigs or dogs, and those with four-chambered stomachs, like cows and deer. While chevrotains do have four stomach chambers, one of them (the omasum) is smaller and less developed than in other modern ruminants, making their digestive system somewhat intermediate.

Chevrotains are also classified as ungulates and ruminants. Ungulates are simply animals with hooves. This diverse group includes well-known animals like elk, giraffes, wild boars, rhinos, camels, and bison. Ruminants are a specific type of ungulate. They are even-toed hoofed animals that chew regurgitated food. Common examples of ruminants include sheep, cows, deer, and antelopes. Millions of years ago, chevrotains were more widespread and diverse, but today only 10 species remain. These surviving species still possess many ancient, primitive features that are rarely seen in more modern mammals.

The Smallest Hoofed Marvel

Chevrotains are remarkably small animals—about the size of a pet rabbit, cat, or small dog. In fact, they are the smallest hoofed animals on Earth. While the water chevrotain (Hyemoschus aquaticus) can weigh between 15 and 35 pounds, the Java mouse-deer (Tragulus javanicus) is a mere 2.2 to 4.4 pounds. Most chevrotain species fall within the 2- to 9-pound range. Chevrotains have short, slender legs with tiny hoofed feet. They aren’t particularly agile when turning, but their small legs are efficient for running straight and moving through dense vegetation and forests.

Their bodies are round, similar to those of a mouse or rabbit, with small, pointed snouts and large eyes. This unusual combination of features can cause people to mistake them for rodents. Their posture also adds to this confusion, as their longer hind legs make their hindquarters higher than their front. However, their thin legs, reddish or orange-brown coloring, and white markings make them closely resemble a deer. They also have small, pig-like hooves and long, sharp fangs.

No Horns, Just Fangs

Unlike other ruminants, chevrotains never developed horns or antlers. Instead, they have what look like fierce fangs, which are actually elongated canine teeth, also known as tusks. These tusks are especially long and needle-like in male chevrotains, and are used during fights with other males. Fortunately, their thick fur and strong muscles offer protection from bites during these epic conflicts.

Where to Find the Elusive Chevrotain

Chevrotains are shy and mainly solitary animals, making them extremely difficult to find. There are 10 known species, categorized into three genera: Hyemoschus, Moschiola, and Tragulus. While the terms “chevrotain” and “mouse-deer” are often used interchangeably, researchers are beginning to distinguish between them: “chevrotains” generally refer to Moschiola and Hyemoschus, while “mouse-deer” refers to Tragulus.

Nine of the 10 species live in South and Southeast Asia. Only one species, the water chevrotain, lives in Central and West Africa. Researchers struggle with studying these elusive animals because they live alone and are only active at night. Females typically have just one baby at a time, which is weaned quickly (around three months) and becomes sexually mature between five and ten months old.

Chevrotains are not only small but also incredibly good at navigating and hiding in dense forest vegetation. They are mostly silent as well, making them very difficult to detect. The silver-backed chevrotain (Tragulus versicolor), for example, is so elusive that it wasn’t officially seen alive between 1990 and 2017, when it was finally captured on camera for the first time.

These tiny creatures are hunted by large predators like crocodiles, snakes, cats, and raptors. Fortunately, their secretive nature and hiding skills help them survive. The water chevrotain, for example, can escape into rivers when chased. These small animals can press their bodies against the riverbed and walk along it, much like tiny hippos or submarines. They can stay submerged for up to four or five minutes, and when they surface for air, they do so stealthily in shaded or plant-covered areas.

Foraging and Chewing the Cud

Chevrotains are herbivores and eat leaves, berries, fruits, and aquatic plants. They are also ruminants, meaning they have a multi-chambered stomach similar to that of a cow. This allows them to “chew their cud.” They swallow their food, which is partially broken down in their stomachs, and then bring it back up to their mouth to chew a second time. This re-chewing helps them extract as many nutrients as possible from their plant-based diet. While most chevrotains stick to a plant-based diet, the water chevrotain is an exception. It primarily eats plants but will occasionally consume crabs, insects, or even dead fish if available.