The blue whale is the world’s largest living mammal: you’ve likely heard that fact so many times that you could recite it in your sleep. But have you ever stopped to wonder about the other end of the spectrum? What are the smallest mammals in the world?
Although most of them are not well-known to humankind, many amazing tiny mammals live on this planet. They adapt to harsh environments while dodging predators a hundred times their size. Although their miniature size can make life more challenging, it offers them ecological advantages, too: they can survive on less food and water than a larger animal can, and they can climb and hide in places larger animals could never go. Some tiny mammals even manage to be fierce and effective hunters!
Read on to learn more about the fascinating small worlds of these unusual mammals.
10. Pink Fairy Armadillo (Chlamyphorus truncatus) — above
The fabulous pink fairy armadillo is the smallest of all the armadillo species, at only 3.5–4.5 inches (90–115 mm) long. They live in central Argentina, where they spend most of their time underground. Their front claws allow them to dig through sandy earth freely, and they can completely bury themselves in seconds if frightened.
9. Least Weasel (Mustela nivalis)
The least weasel is the world’s smallest carnivore, occurring throughout Eurasia, North America and North Africa. They can weigh as little as 1.04 ounces (29.5 grams) or as much as 8.8 ounces (250 grams). Their size is also very variable, but they can be as small as 5 inches (131 millimeters) long, including the tail! Don’t let that fool you—despite their petite size, they are formidable and fierce hunters.
8. Madame Berthe’s Mouse Lemur (Microcebus berthae)
Madame Berthe’s mouse lemur is the tiniest primate in the entire world. Like all lemurs, they live in Madagascar; these mouse lemurs live in only one region, Kirindy Mitea National Park. They are a mere 3.6 inches (92 millimeters) long, with an average weight of 1.1 ounce (30 grams). The species is named after Madagascar’s famous conservationist Madame Berthe Rakotosamimanana.
Note: The photo above is of a Pygmy mouse lemur (Microcebus myoxinus), a closely related species.
Photo Credit: User:Bikeadventure [Public domain], via Wikimedia Commons
7. Eastern Pygmy Possum (Cercartetus nanus)
These marsupials live in habitats around southeastern Australia. They are 2.8–3.5 inches (7–9 centimeters) long, with a talented prehensile tail; at 3.1–4.3 inches (8–11 centimeters) long, that tail is even longer than the body itself! They are talented climbers, which serves them well, as they love to feed on nectar and pollen from tree flowers.
6. American Shrew Mole (Neurotrichus gibbsii)
The American shrew mole lives in forested or bushy areas in the northwestern United States, stretching up into southwest British Columbia. They weigh only 0.35 oz (10 grams), and are about 3.9 inches (10 centimeters) long. They prefer to dig through deep, loose soils, and they also frequently venture above ground, foraging for tasty earthworm and insect snacks.
Photo Credit: Jules Evens, Bay Nature
5. Long-Tailed Planigale (Planigale ingrami)
You may never have heard of planigales before, but these planigales are the smallest of all marsupial species. They live in plains, clay woodlands, and flooded grasslands in northern Australia. They weigh a miniscule 0.15 ounces (4.3 grams), and they average 2.3 inches (59 millimeters) long, not counting the tail. They are most notable for their unusual head shape: it’s long and wide but not very deep, which produces a shovel-like shape that allows the animal to squeeze through the smallest cracks in the soil.
Photo Credit: Richard King, WA Zoologist
4. Pygmy Jerboa (Salpingotulus michaelis)
The pygmy jerboa is one of the two smallest rodents in the world (tied with #3 on our list). They live exclusively in Pakistan’s sand dune deserts, where they travel by means of extraordinary kangaroo-like hops, balancing themselves on their tails when they pause. They are only 1.7 inches (4.4 centimeters) long, plus a 3.1-inch (8 centimeter) tail. They weigh 0.132 ounces (3.75 grams), and feed mostly on succulent desert leaves and wind-blown seeds.
Note: The photo above is of a Four-toed Jerboa (Allactaga tetradactyla), a closely related species.
Photo Credit: Syt55 (Own work) [Public domain], via Wikimedia Commons
3. African pygmy mouse (Mus minutoides)
Along with the pygmy jerboa (#4), the African pygmy mouse is the world’s smallest rodent. They weigh 0.11–0.42 ounces (3–12 grams), and are 1.2–3.1 inches (30–80 millimeters) long, not including the tail. They live in sub-Saharan Africa, so they have developed a very clever method of getting water: the mouse stacks pebbles in front of its burrow, the pebbles gather dew overnight, and the mouse can sneak out pre-dawn to drink the accumulated dew.
Photo Credit: AleXXw (Own work) [Public domain], via Wikimedia Commons
2. Etruscan Shrew (Suncus etruscus)
The Etruscan shrew has the smallest mass of any mammal known to mankind, weighing in at an astounding 0.063 ounces (1.8 grams). Since they are so tiny, they have a very fast metabolism, so they need to eat 1.5 to 2 times their body weight each day, which may mean as many as 25 feedings. If they are not asleep or hiding, then they are in constant motion. Their heart rate is 1,511 beats per minute! They live in warm, damp climates scattered throughout Eurasia.
1. Bumblebee Bat (Craseonycteris thonglongyai)
Last—and least!—the bumblebee bat is the smallest mammal in the entire world.* They live in limestone caves near rivers in Thailand and Burma, in colonies of about 100 bats. They are a petite 1.1–1.3 inches (29–33 mm) in length, and weigh 0.071 ounces (2 grams)—that’s roughly the same as a single raspberry! Their long-tipped wings allow them to hover in mid-air, and they have a handsome pig-like snout.
*While the Etruscan shrew has a lower mass, the bumblebee bat has a smaller skull and a shorter overall length.
Photo Credit: Daniel Hargreaves, EDGE Blog