50 Fun Facts About Animal Adaptations

What does a camel's hump actually store, going limp and drooping when the animal has gone without food?

Fat, not water, fills a camel's hump as a reserve of calories for when food is scarce. The idea that the hump is a water tank is a common myth.

What color is the skin hidden beneath a polar bear's thick fur?

Black skin under the coat helps a polar bear absorb heat. The hairs themselves have no pigment: they are hollow and transparent, and only look white because of the way they scatter light.

Which carnivorous plant snaps shut only after its trigger hairs are touched twice within about twenty seconds?

The Venus flytrap counts touches so that falling raindrops do not set it off. Two quick signals mean live prey, and the trap closes in about a tenth of a second.

Which African animal's coat pattern stops biting flies from landing, even when horses wear a copy of it?

Zebra stripes kept biting flies from landing in a 2019 study, both on the animals themselves and on horses dressed in printed coats. From a distance the insects were not put off at all.

Which sea animal sleeps with only one half of its brain at a time, staying alert enough to surface and breathe?

Dolphin sleep shuts down only one brain hemisphere at a time. The half that stays awake keeps the animal breathing and on the lookout for predators and other threats.

Which African mammal uses a grasping tongue about 45 cm long to pick leaves from acacia trees?

The giraffe's tongue is dark, perhaps to protect it from sunburn during long hours of feeding. It can grasp foliage and delicately pick off leaves at heights most other plant-eaters cannot reach.

Which winter survival strategy slows a groundhog's heart to as few as four beats a minute?

Hibernation also drops a groundhog's body temperature to as low as 2 °C and its breathing to one breath every six minutes. Running that slowly, the animal can last until spring without eating.

Which seabird sees two summers a year by flying from its northern breeding grounds to Antarctica and back?

The Arctic tern makes by far the longest yearly journey known in the animal kingdom. One tagged bird from England's Farne Islands covered 96,000 km in just ten months.

Which survival trick do a flounder matching the seabed and a ptarmigan turning white for winter both rely on?

Camouflage hides an animal by making it hard to see or by disguising it as something else. A peacock flounder can redraw its pattern within minutes of settling on a new patch of seabed.

Which metal in the enamel gives a beaver's tree-felling front teeth their orange color?

Iron compounds color the thick enamel on a beaver's incisors orange or reddish-brown. The four chisel-shaped teeth keep growing throughout the animal's life.

Which North American amphibian survives winter frozen, with no heartbeat, breathing or blood circulation?

The wood frog loads its tissues with urea and glucose, which limit how much ice forms and protect its cells. In the wild it has been recorded frozen for about 193 days in a row.

Which butterfly's eastern population flies up to 3,000 miles to spend the winter in Mexico?

Monarch journeys on this scale take more than one lifetime. It is the second, third and fourth generations that arrive back at the northern breeding grounds each spring.

Which sense lets bats hunt insects in total darkness and toothed whales find prey in murky water?

Echolocation, also called bio sonar, means calling out and listening for the echoes that bounce back. Some moths can hear the calls coming, so 'whispering' bats have evolved much quieter ones.

Which defense do harmless hoverflies use when their yellow stripes make birds mistake them for stinging wasps?

Mimicry lets a hoverfly borrow a wasp's reputation without having a sting of its own. This kind, where a harmless species copies a dangerous one, is named after naturalist Henry Walter Bates.

Which thick insulating layer beneath the skin keeps whales, seals and walruses warm in icy seas?

Blubber also adds buoyancy and streamlines the body of a marine mammal. On cold dives the blood vessels around it tighten, which makes it an even better insulator.

Tarsiers have enormous eyes for their body size, an adaptation to which daily pattern of activity?

Nocturnal animals are active at night, and outsized eyes make up for the low light. Most also lean on highly developed senses of hearing and smell.

Which process, set out by Charles Darwin in 1859, makes helpful inherited traits more common over generations?

Natural selection means that individuals whose traits suit their surroundings survive and breed more often. Darwin popularized the name as a contrast with the intentional choices of breeders.

Which Galápagos birds, collected by Charles Darwin on the Beagle voyage, have beaks shaped for different foods?

Finches on the Galápagos, about 18 species in all, differ most in the size and shape of their beaks. Darwin took some for grosbeaks and one for a wren until ornithologist John Gould examined them.

Which Antarctic bird survives 200 km/h winter winds by huddling tightly and taking turns in the warmer middle?

Emperor penguin colonies pack into a huddle of up to several hundred birds, each leaning forward on a neighbor. The arrangement is also known as the turtle formation.

Which small Sahara mammal has unusually large ears that shed body heat and pick up prey moving underground?

The fennec fox is the smallest member of the dog family, yet its ears are about 10 cm long. Its large, dense kidneys help it hold on to water when there is little to drink.

Which North American desert rodent never needs to drink, getting its water from the dry seeds it eats?

The kangaroo rat makes all the water it needs as a by-product of breaking down seeds. A lowered metabolic rate also cuts the moisture it loses through its skin and breath.

Which Australian reptile collects water on its skin, where channels between the scales carry it to the mouth?

The thorny devil can drink just by touching water with any part of its body, usually its legs. Capillary action does the rest, even pulling moisture out of damp sand.

Which reptiles walk up vertical glass on footpads carrying about 14,000 hair-like bristles per square millimeter?

Geckos cling without any liquid: their tiny bristles, called setae, grip through weak forces between molecules. About 60% of the species have these sticky toepads.

Which American snakes track warm-blooded prey using a heat-sensing pit between each eye and nostril?

Rattlesnakes, like all pit vipers, pick up the infrared given off by warm-blooded animals. The pits work only over about a foot, but that is a distinct advantage when hunting at night.

Which Australian mammal hunts underwater with eyes, ears and nostrils shut, sensing its prey's electric signals?

The platypus has about 40,000 electroreceptors in the skin of its bill. They pick up the tiny currents made by the twitching muscles of prey hidden in the stream bed.

Which birds of prey fly almost silently because serrated edges on their wing feathers muffle each wingbeat?

Owls also fly more slowly than other birds of prey. Those that hunt by day have less need of a silent approach, since their prey can usually see them coming.

Which tiny birds enter torpor at night, slowing their metabolism to one-fifteenth of its normal rate?

Hummingbirds drop into this deep-sleep state to stop their energy reserves falling to a critical level. They can also use it by day, whenever food is hard to find.

Which deep-sea fish attracts prey with a glowing lure that is really a modified ray of its dorsal fin?

Anglerfish are named for this fishing-rod trick. Their thin, flexible bones let the jaws and stomach stretch so far that they can swallow prey up to twice their own size.

Which big cat has blunt claws that only partly retract because they lack a protective sheath?

The cheetah's scientific name, Acinonyx, probably comes from Greek words meaning 'immobile nails'. Its sharp dewclaws do a different job, hooking the legs or rump of fleeing prey.

Which North American mammal swaps a short brown summer coat for a longer white one each winter?

The snowshoe hare is named for its outsized hind feet, which keep it from sinking into soft snow. Its other name, the varying hare, comes from the seasonal change of coat.

Which of these is a behavioral adaptation rather than a physical one?

Nut hoarding is an action, so it counts as behavior, while armor, fur and talons are structures. Squirrels that cache in the warmer months gain a real survival advantage in a harsh winter.

Which of these is a physical adaptation rather than a behavioral one?

A prehensile tail is a body part, which makes it a structural adaptation. Spider and howler monkeys grip branches with theirs, helped by a bare patch of touch-sensitive skin.

Which word describes inborn behavior, such as newly hatched sea turtles heading straight for the ocean?

Instinct covers complex behavior performed with no earlier experience or learning. It differs from a reflex, which is a simple response such as a pupil shrinking in bright light.

Which part of a cactus is a highly modified leaf, kept by most species after true leaves were lost?

Spines came first: even the few cacti that still grow true leaves have them. Botanists keep the word 'thorn' for a modified branch instead.

Which plant's clinging seed burrs, caught in a dog's fur, inspired George de Mestral to invent Velcro?

Burdock burrs hitch a ride on passing animals, an excellent way of spreading seeds. In German the fastener is still called a Klettverschluss, literally a 'burdock fastener'.

Which coastal trees send up root-like tubes that stick out of the mud like straws to take in air?

Mangroves grow in waterlogged mud with little oxygen, so these pneumatophores let them breathe straight from the atmosphere. Other species prop themselves above the water on stilt roots.

Which word describes trees such as maple and birch that shed their leaves to save water through winter?

Deciduous trees pay for the habit by regrowing all their foliage in the next growing season, a cost evergreens avoid. Bare branches may also suffer less damage from insects.

What does the titan arum's giant bloom smell of, a stench strongest in the middle of the night?

Rotting meat is the scent of choice because the plant's pollinators, carrion beetles and flesh flies, feed or lay their eggs on carcasses. The bloom heats itself to about 37 °C to spread the smell.

Which pattern, also called Thayer's law, gives sharks and many other animals a dark back and a pale belly?

Countershading cancels out the shadow that light from above casts on an animal's underside, so the body looks flat. Abbott Thayer, who gave the law its name, was an American painter.

Which summer dormancy lets African lungfish survive months of drought by burrowing into mud?

Estivation is entered in response to high temperatures and arid conditions. Land snails do it too, sealing their shells with a film of dried mucus to keep moisture in.

Which insect defends itself by ejecting a hot, noxious chemical spray from its abdomen with a popping sound?

The bombardier beetle sets off a chemical reaction inside its abdomen that heats the spray to near the boiling point of water. Some species can aim the jet in a wide range of directions.

Which North American reptile can squirt an aimed stream of blood from the corners of its eyes at predators?

The horned lizard restricts the flow leaving its head until the pressure bursts tiny vessels around its eyelids. The jet can travel up to 1.5 m.

Which tropical fish shoots down insects up to three meters above the surface with a jet of spat water?

The archerfish even corrects its aim for the way light bends where air meets water. It fires by squeezing its gill covers, forcing a stream out through a channel in its mouth.

Which eight-legged micro-animal can dry out into a dormant 'tun' and has survived exposure to outer space?

The tardigrade draws in its legs and stops its metabolism completely when its moss or pond dries out. In that state it can withstand temperatures from −272 °C to 149 °C.

Which Madagascan lemur taps on trees to find hollows, then hooks out grubs with a thin middle finger?

The aye-aye fills the niche of a woodpecker, reaching insects sealed inside tree trunks. It gnaws its way in with rodent-like teeth that never stop growing.

In which African desert do head-standing insects climb dunes in fog so droplets run down into their mouths?

The Namib's animals and plants rely on fog blowing in off the ocean as their main source of water. The trick is called fog-basking, and only two closely related beetles are known to do it.

Which bird crosses the Himalayas between Central Asia and India, sometimes nonstop in as little as seven hours?

The bar-headed goose is known for the extreme altitudes it reaches on the crossing. Even so, tagged birds spent 95% of their time below 5,800 m, choosing valleys and passes over peaks.

Which term describes insects, birds and bats each gaining the power of flight independently?

Convergent evolution gives unrelated animals similar answers to the same problem. A bat's wing and a bird's wing do the same job, yet the two are built quite differently.

Which principle, named for a German biologist, says warm-blooded animals tend to be larger in colder climates?

Bergmann's rule is named after Carl Bergmann, who described the pattern in 1847 but was not the first to notice it. A companion rule, Allen's, deals with body proportions instead of overall size.

Which insect performs a figure-eight 'waggle dance' to tell nestmates the direction and distance of flowers?

The honey bee's dance is a code: a waggle run straight up the comb points toward the sun, and any angle off vertical gives the bearing. Nobel laureate Karl von Frisch was among the first to decode it.