99 Fun Facts About Mammal

Which of these features is found in mammals and in no other class of animal?

Mammary glands mark the class, while birds share the four-chambered heart and warm blood. The platypus has the glands but no teats, so its milk seeps out through pores in the skin.

What is the largest mammal on Earth?

Blue whale: the largest animal known ever to have lived reaches about 30 metres, yet it feeds almost entirely on krill, straining them from huge mouthfuls of sea water.

The platypus and the echidnas form which group of mammals, the only ones that lay eggs?

Monotremes means 'single opening' in Greek: unlike most mammals, they have one vent that serves for waste, mating and laying eggs.

Which land mammal is recognized as the fastest over short distances?

Cheetah: it reaches highway speed in about three seconds, but a full sprint lasts well under a minute, so it stalks close to its prey before it charges.

Echolocation is shared with whales and shrews, so which ability is unique to bats among mammals?

Sustained flight is theirs alone, since flying squirrels and sugar gliders only glide. Wings took bats where other land mammals never reached: they are New Zealand's only native land mammals.

Most of the world's living marsupial species are found on which continent and its nearby islands?

Australia is where they flourished, not where they began: DNA points to a single migration from South America, made while Antarctica still linked the two continents.

Which animal carries its young for around 22 months, the longest gestation of any mammal?

African elephant: after a pregnancy of nearly two years the calf is born so well developed that it is on its feet soon after birth.

Two of a mammal's three middle-ear bones began as bones of which body part?

The jaw once hinged on them: when early mammals evolved a new jaw joint, the two old hinge bones shrank and moved into the ear, becoming the hammer and anvil.

A whale's blowhole is the evolved form of which body part found on other mammals?

Nostrils: over millions of years they moved to the top of the head, so a whale can take a breath while almost all of its body stays under water.

Lemurs, tarsiers, monkeys, apes and humans all belong to which order of mammals?

Primates means 'of the first rank' in Latin, coined for what was seen as the highest order of mammals, and the group as first drawn up also included bats.

Llamas and alpacas of South America belong to the same family as which Old World animals?

Camels share the family, which first appeared in North America and only later spread over land bridges to Asia and South America.

A porcupine's quills are a modified form of which body covering?

Hair is what each quill is, thickened into a barbed spine. No porcupine can throw its quills, but they detach easily and the barbs work them deeper into an attacker.

Which is the largest order of mammals by number of species?

Rodents make up about 40% of all mammal species, and the name comes from the Latin for 'gnawing': their front teeth never stop growing, so they must keep wearing them down.

Which prehistoric animal, often mistaken for a dinosaur, was in fact an early relative of mammals?

Dimetrodon died out some 40 million years before the first dinosaurs appeared, and it belongs to the synapsids, the line that led to mammals rather than to reptiles.

A beaver's front teeth are orange because their enamel contains which metal?

Iron compounds colour the enamel and make it harder and more resistant to acid, which helps teeth that never stop growing stand up to a lifetime of cutting wood.

Which is the largest living ape?

Gorilla: for all its size and strength it is a quiet plant-eater, living mainly on leaves, stems and fruit.

Naturalists who saw the first platypus specimen suspected a fake, with which part sewn onto another animal's body?

Its bill looked so like a duck's that George Shaw, who first described the animal in 1799, wrote that it was impossible not to doubt it was genuine.

Where does the male platypus deliver its venom from?

A spur on each hind foot is wired to a venom gland in the leg; only males keep the spurs into adulthood, and the sting is strong enough to cause a person severe pain.

Which animal, at around two grams, is the world's smallest mammal by mass?

Etruscan shrew: to keep so small a body warm it burns energy at a furious rate, and its muscles contract faster than those of any other mammal.

Kitti's hog-nosed bat, a rival for the title of smallest mammal, lives in Myanmar and which neighbouring country?

Thailand: it roosts high in limestone caves there, and at about two grams it is no bigger than a large bumblebee, which is why it is also called the bumblebee bat.

The bat order name Chiroptera comes from Ancient Greek words meaning what?

Hand wing: a bat's wing is skin stretched across four greatly lengthened fingers, so the animal in effect flies on its hands.

Guinea pigs were first domesticated in which mountain range?

Andes villagers have bred guinea pigs for meat for thousands of years, and still do: the animal Europe adopted as a pet is neither a pig nor from Guinea.

True seals have only ear holes, so which of their relatives can be told apart by small external ear flaps?

Sea lions belong to the eared seals, and they can also turn their hind flippers forward to walk on all fours, while a true seal on land has to wriggle along on its belly.

An elephant's tusks are modified versions of which teeth?

Incisors: each tusk is an upper front tooth that keeps growing throughout the elephant's life, by several inches a year, and serves as a tool for digging, stripping bark and fighting.

Which mammal lives in underground colonies run like a beehive, with a single breeding queen?

Naked mole-rat colonies work like those of ants and bees: only the queen and one to three males breed, while every other member spends its life as a worker or soldier.

Which farm animal stands on the tip of a single toe on each foot?

Horse: each hoof caps the one toe it has left, the legacy of dog-sized ancestors that walked on four toes in front and three behind some 50 million years ago.

Which Arctic whale may be the longest-lived of all mammals, reaching more than 200 years?

Bowhead whales landed by Alaskan hunters have carried harpoon tips more than a century old, the first hard evidence of a lifespan that no other mammal is known to match.

A wild sloth's fur often looks green because what grows in it?

Algae grow in grooves that run along each strand, and the greenish tint helps hide the slow-moving sloth in the canopy from predators that hunt by sight.

Sloths are most closely related to which other animals, together making up the order Pilosa?

Anteaters and sloths look nothing alike, yet they share an order, and their next nearest relatives are the armadillos: all three groups arose in South America.

Which mammals, poached for their meat and scales, are the world's most trafficked?

Pangolins roll into a tight ball when threatened, their overlapping scales working as armour, but that armour is what poachers are after: the scales are sold for use in traditional medicine.

What are baby echidnas called?

Puggles hatch after about ten days and stay in the mother's pouch until their spines start to grow, when she moves them to a nursery burrow.

A popular myth says 'kangaroo' came from an Aboriginal phrase meaning what?

'I don't know' is the legend, supposedly the reply Captain Cook's party got in 1770, but gangurru was simply the Guugu Yimithirr name for one kind of kangaroo.

Which is the largest living marsupial?

Red kangaroo: its tendons work like springs, storing the energy of each landing for the next bound, so hopping fast costs it very little effort.

What are the closest living relatives of the koala?

Wombats are burrowers, yet they share with the tree-living koala a pouch that opens to the rear, a design that keeps soil off a wombat's young while it digs.

Koalas sleep up to 20 hours a day because which food gives so little energy?

Eucalyptus leaves are tough, poor in calories and toxic to most other animals, so a koala saves energy by moving little and sleeping most of the day.

The name 'armadillo' is Spanish for what?

Little armoured one is what Spanish speakers called it for its bony plates, yet, contrary to popular belief, only the three-banded armadillos can curl up into a ball.

Which North American mammal is famous for seeming to wash its food in water before eating it?

Raccoon: it is not really cleaning anything, as the belief comes from the way it hunts, feeling for food in or near water and handling it as it eats.

The world's largest bats, with wingspans of 1.5 metres or more, are known by what name?

Flying foxes feed on fruit and, unlike most bats, do not echolocate: they find their way by sight.

Besides being the tallest land animals, giraffes are the largest members of which group?

Ruminants chew the cud, so each ball of leaves a giraffe swallows travels all the way back up to its mouth for a second chewing before its four-part stomach finishes the job.

With its eyes shut underwater, a platypus finds prey by sensing what?

Electric signals from the twitching muscles of its prey are picked up by sensors in its snout, which takes over as the main sense organ once a dive begins.

Which animal has the largest brain on Earth, more than five times heavier than a human's?

Sperm whale: its huge square head makes up about a third of its length, yet most of that space holds not brain but spermaceti, the waxy oil the animal is named after.

Despite looking like pigs, hippos' closest living relatives are which animals?

Whales and dolphins are the hippo's nearest kin: DNA and fossils show the two lines parted more than 50 million years ago, when the earliest whales were still four-legged land animals.

The male narwhal's long spiral tusk is a tooth that grows out through which part of its head?

Its upper lip: the tooth spirals straight out through it to a length of up to three metres, and such tusks were once sold as the horns of unicorns.

Despite the Dracula legend, vampire bats live only in which part of the world?

Latin America is home to all three species, and none of them sucks blood: a vampire bat makes a small cut in a sleeping farm animal and laps up what flows.

The aye-aye taps on trees, then pulls grubs out of the wood using what?

A long, thin middle finger does both jobs: it drums on the bark while the aye-aye listens for hollow tunnels, then, once the animal has gnawed a hole, it hooks the grub out.

The okapi, a striped relative of the giraffe, lives wild only in the rainforests of which country?

DR Congo's dense Ituri rainforest hid the okapi from scientists until 1901, although the people of the forest had known the animal for generations.

The star-nosed mole's star of fleshy tentacles is an organ of which sense?

Touch: the tentacles tap up to a dozen spots a second, letting the mole find and swallow a morsel in as little as 120 milliseconds, the fastest eating known in any mammal.

Dugongs and manatees form which order of fully aquatic plant-eating mammals?

Sirenia is named for the sirens, because sailors' tales of mermaids are thought to have begun with glimpses of these slow, plant-eating animals, also known as sea cows.

When a blue whale dives deep to feed, what happens to its heartbeat?

It slows sharply, to as few as two beats a minute, which makes the oxygen in its blood last longer; back at the surface the heart speeds up to as many as 37 beats.

How much blood pressure does a giraffe's heart generate compared with a human's?

About double: a giraffe's head can be two metres above its heart, and pushing blood that far uphill against gravity takes thick heart walls and constant high pressure.

Which species is the largest living land carnivore by body mass?

Polar bear fur only looks white: the skin beneath is black, and each strand of the outer coat is a clear, hollow tube.

Which animal became the largest carnivorous marsupial after the thylacine died out?

Tasmanian devil: no bigger than a small dog, it has, pound for pound, one of the most powerful bites of any mammal and can eat a carcass bones, fur and all.

The last known thylacine, or Tasmanian tiger, died in 1936 at a zoo in which city?

Hobart's Beaumaris Zoo lost the last known animal on 7 September 1936, only two months after the species was finally given legal protection.

Cuvier's beaked whale holds the mammal diving record at nearly three kilometres down, where it hunts mainly what?

Squid are its main prey, caught by suction in the dark; one tagged whale reached 2,992 metres and another stayed under for 222 minutes, both records for any mammal.

Wombats pile up their cube-shaped droppings to do what?

Mark territory: the flat sides are thought to stop the droppings rolling away, and the corners are moulded in the last stretch of the wombat's intestine.

Often called the American antelope, which animal is the fastest land mammal in North America?

Pronghorn: despite the nickname it is no true antelope but the last survivor of a family found only in North America, and it can keep up a fast pace over long distances.

Almost every mammal, from a mouse to a giraffe, has exactly seven bones in which part of its body?

The neck holds seven bones in a mouse and a giraffe alike, the giraffe's being simply far longer; the rare rule-breakers are the manatees, with six, and the sloths.

Which is the largest living rodent?

Capybara: a barrel-shaped relative of the guinea pig, it has slightly webbed feet and can stay underwater for up to five minutes to hide from predators.

The rock hyrax looks like a large guinea pig, but its tiny tusks mark it as a close relative of which giants?

Elephants, hyraxes and sea cows share a common ancestor, and the likeness survives in the hyrax's tusk-like upper teeth and its stumpy toes with hoof-like nails.

The orca, or killer whale, is the largest member of which family?

Oceanic dolphins count the orca as their biggest member, and it is the ocean's top predator: nothing hunts it, while it takes seals, sharks and even other whales.

Which marine mammal keeps warm with the densest fur of any animal?

Sea otter: its coat traps a layer of air against the skin, and the animal spends hours every day grooming to keep that coat clean and waterproof.

The giant panda's 'false thumb' is really an enlarged what?

Wrist bone: covered by a fleshy pad, it works against the panda's five true fingers like a thumb, so the bear can grip a bamboo stalk while it eats.

Which wild animals were the first that humans ever domesticated?

Wolves came first: they had become the dog at least 15,000 years ago, among people who still lived by hunting and gathering, thousands of years before any farm animal was tamed.

Which small Arctic animals are wrongly believed to commit mass suicide by leaping off cliffs?

Lemmings do no such thing: the myth is old, but a 1958 Disney nature film faked the proof, with the crew throwing the animals off a cliff for the camera.

Which animal is the northernmost marsupial in the world, ranging into southern Canada?

Virginia opossum: it also gave English the phrase 'playing possum', because a badly frightened one drops limp and lies as if dead, sometimes for hours.

The saola, a forest bovid first described in 1993, was discovered in which country?

Vietnam's Vu Quang forest gave up the first evidence in 1992, a long-horned skull kept in a hunter's home, and no scientist has yet reported seeing a saola alive in the wild.

Steller's sea cow, a manatee cousin wiped out in the 1700s, lived in which sea?

Bering Sea: the naturalist Georg Steller described the animal in 1741 while sailing with Vitus Bering's expedition, and hunters had killed the last one less than 30 years later.

The quagga, wiped out by hunters in 1800s South Africa, was a kind of what?

Zebra: the quagga was striped only on its head and forequarters, fading to plain brown behind, and DNA from museum skins showed it was a form of the plains zebra.

The upper canines of a male babirusa grow out through which part of its body?

The skin of its snout is pierced from beneath by the tusks, which then curve back toward the forehead and, if never worn down, can in rare cases grow into the skull.

Qiviut, a fibre prized for its softness and warmth, comes from which animal?

Muskox: beneath its shaggy outer coat lies a fine underwool that the animal sheds every year, and this is gathered and spun into a yarn often compared with cashmere.

Hippos ooze a red fluid nicknamed 'blood sweat', which is neither blood nor sweat, to act as what?

Sunscreen: the fluid oozes out clear and turns red-orange within minutes, and its pigments both soak up ultraviolet light and slow the growth of bacteria on the hippo's skin.

Which of these big cats cannot roar, although it can purr?

Snow leopard: its throat is built more like that of a small cat, so instead of roaring it hisses, growls, yowls and greets others of its kind with a soft puffing sound called a chuff.

The numbat, a small striped marsupial, uses its long sticky tongue to eat almost nothing but what?

Termites: too weak to break into a mound, the numbat hunts by day, when the insects travel through shallow tunnels, which makes it one of the very few marsupials active in daylight.

How does the gerenuk antelope reach leaves above its rivals?

Standing on its hind legs at full stretch, the gerenuk browses above the reach of its rivals, and it takes in so much moisture with the leaves that it does not need to drink.

Merriam's kangaroo rat can survive without ever drinking; where does its water come from?

Oxidising the seeds it eats releases water inside its body, and almost none is wasted: the animal neither sweats nor pants, and its kidneys pass waste with very little water.

Which African mammal's name means 'earth pig' in Afrikaans?

Aardvark: the name fits its pig-like snout and its burrowing, yet it is not closely related to pigs and is the only living species in its whole order of mammals.

Which small, quick mammal of Africa and Asia is famous for fighting and killing cobras?

Mongoose: it relies on speed and agility, darting in to bite the snake's head, and its body also has a built-in resistance to the venom if a strike does land.

Which naturalist introduced the class name Mammalia in 1758?

Carl Linnaeus introduced the name in the tenth edition of his Systema Naturae, the book zoologists still treat as the starting point for the scientific naming of all animals.

Cloned sheep Dolly was named after Dolly Parton because her source cell came from a ewe's what?

Udder: born in Scotland in 1996, Dolly was the first mammal ever cloned from an adult cell, and she went on to have six lambs of her own.

Laika, the dog who in 1957 became the first animal to orbit Earth, had been a stray in which city?

Moscow: Soviet scientists picked strays from its streets because they believed dogs that had already survived hunger and bitter cold would cope best with the hardships of a flight.

The baiji, declared functionally extinct in 2006, was a dolphin from which river?

Yangtze: a six-week search of the river in 2006 failed to find a single baiji, making it probably the first dolphin species driven to extinction by human activity.

The vaquita, the world's most endangered marine mammal, lives only in which body of water?

Gulf of California, the narrow sea between Baja California and mainland Mexico, is its only home, and the porpoise is dying out as bycatch in illegal nets set for a fish called the totoaba.

Which rhino species survives only in one Indonesian national park, Ujung Kulon?

Javan rhinos all live on one peninsula near the volcano Anak Krakatau, so a single eruption or tsunami could wipe out the entire species.

Which river separates the ranges of bonobos and common chimpanzees?

Congo: bonobos live only in the rainforest south of the river and chimpanzees to its north, and the broad water is a barrier that neither ape crosses.

In which deer species do females normally grow antlers?

Reindeer: the bulls drop their antlers in late autumn or early winter, but the cows carry theirs right through the cold months, until their calves are born in spring.

Which is the tallest and heaviest living species of deer?

Moose: a bull can stand about two metres at the shoulder and carry antlers nearly as wide, and in Europe the very same animal goes by the name elk.

Born on drifting Arctic pack ice, which mammal is weaned after about four days, the shortest nursing period known?

Hooded seal: its milk is so rich that the pup can double its weight in those few days before its mother leaves for good.

Bracken Cave in Texas shelters the largest known bat colony on Earth each summer, made up of which species?

Mexican free-tailed bat: almost all of them are mothers, which fly up from Mexico each spring to give birth in the cave and raise millions of pups there.

Which hibernating mammal lets its body temperature fall below freezing, the lowest known in any mammal?

Arctic ground squirrel: its core can sink to about −3 °C, yet its blood holds no antifreeze and simply stays liquid below its normal freezing point, a state called supercooling.

Which popular pet routinely eats its own soft droppings so that its food gets digested twice?

Rabbit: it passes two kinds of droppings, and the soft, dark ones are eaten at once, because bacteria in its gut have by then broken the tough grass into nutrients it can absorb.

A camel's hump is really a store of what?

Fat: the hump is a food reserve, not a water tank, and when a camel goes hungry for long enough it shrinks and droops to one side until the animal can feed again.

Which animal became the national mammal of the United States in 2016?

American bison: millions once roamed the continent, but by the late 1800s hunting had left only a few hundred, which makes its recovery one of the great conservation comebacks.

Rhinoceros horns are made of which material, the same stuff as human hair and fingernails?

Keratin horn has no good evidence of any health benefit, yet demand in China and Vietnam keeps black-market prices high enough to drive poaching.

Which cat-like animal is the largest meat-eating mammal on Madagascar?

Fossa: it looks like a small cougar but is not a cat at all, and flexible ankles let it run down tree trunks head-first as it hunts lemurs, its main prey.

Where does the tube-lipped nectar bat store a tongue longer than its body?

Its rib cage holds the base of the tongue, which reaches so deep that one long-tubed flower, Centropogon nigricans, depends on this bat alone for pollination.

Which small nocturnal animal has eyeballs that are each about as large as its entire brain?

Tarsier: its eyes are so big that they cannot turn in their sockets, so instead the animal swivels its whole head, nearly 180 degrees in either direction, much as an owl does.

Which ape's name comes from Malay words meaning 'person of the forest'?

Orangutan joins the Malay words orang, 'person', and hutan, 'forest', and the name fits the only great ape of Asia, which spends most of its life in the trees and sleeps in a nest of branches.

Despite their dog-like build, hyenas are genetically closer to which animals?

Cats, civets and genets are all closer kin to the hyena than any dog is, and the spotted hyena is no mere scavenger but a strong hunter whose clans can bring down a full-grown wildebeest.

Colugos, gliding mammals of Southeast Asia, are better known by what name?

Flying lemurs are neither lemurs nor true fliers: a broad membrane of skin joining all four limbs and the tip of the tail lets a colugo glide some 70 metres between trees while losing little height.