97 Animals That Start with M

Illustration with different animal species and text saying animals that start with M

No matter how many animals you learn about, there are always more creatures out there. It’s impossible to list every animal in existence, so focusing on certain species of every letter of the alphabet is a great method to expand your wildlife vocabulary.

So what animal species begin with the letter M? The variety of animals starting with this letter may amaze you!

List of Animals That Start with M

Here are 97 animal species that start with the letter M.

1. Macaroni Penguin

Group of macaroni penguins
  • Scientific Name: Eudyptes chrysolophus
  • Habitat: Rocky, water-bound areas in the Antarctic Peninsula
  • Size: 10 to 12 pounds
  • Diet: Crustaceans, fish, squid

Macaroni penguins gather in colonies that can have up to 100,000 birds. These large groups help the penguins survive predators. Each penguin has unique sounds, so they can find their relatives by listening carefully. When hunting, these birds may dive up to 200 feet below the water’s surface to find prey. On land, they may occasionally swallow small stones to help them digest hard-shelled crustaceans.

2. Madagascan Blue Pigeon

Madagascan blue pigeon sitting on branch
  • Scientific Name: Alectroenas madagascariensis
  • Habitat: Tropical moist forests of Madagascar
  • Size: 9.8 to 10.6 inches long
  • Diet: Fruits

These birds are the only blue pigeons on Madagascar. They only feed on fruit from fruit trees, and they forage in pairs or small groups of up to 12. They built their twig nests in trees 20 to 66 feet off the ground, and they only lay one egg per clutch. All their feathers are blue except for the deep red ones on the end of their tails. They may migrate to different areas of Madagascar during rainy seasons.

3. Madagascan Mantella

Madagascan mantella on leaf
  • Scientific Name: Mantella madagascariensis
  • Habitat: Forest of Madagascar
  • Size: About 1 inch long
  • Diet: Ants, termites, fruit flies

Madagascan Mantellas are a vulnerable species of Mantella frog that’s only native to Madagascar. Their brightly-colored skin lets predators know that they can release toxic skin secretions. They get their toxins from the invertebrates they eat, so when raised in captivity, they’re often not poisonous. Their toxins rarely kill animals, but they can make creatures ill, and the toxins taste foul. These frogs spend most of their time on the ground in moist forests.

4. Madagascar Hissing Cockroach

Madagascar hissing cockroaches
  • Scientific Name: Gromphadorhina portentosa
  • Habitat: Forest floors of Madagascar
  • Size: 2 to 4 inches long
  • Diet: Decaying plant matter

These are one of the largest cockroach species, and they’re known for making loud hissing sounds. They usually hiss when they’re disturbed. These critters can distinguish one cockroach’s hissing sound from another’s. They’re only native to Madagascar, but they’re also commonly kept as exotic pets. While most cockroaches lay eggs, these insects incubate the eggs inside their bodies and have live births.

5. Madagascar Nightjar

Pair of Madagascar nightjars
  • Scientific Name: Caprimulgus madagascariensis
  • Habitat: Subtropical or tropical forests of Madagascar
  • Size: 8.2 to 9 inches long
  • Diet: Insects

The unique brown patterns on these birds’ feathers allow them to blend into trees and leaf litter when resting. They can flatten themselves on the ground and close their eyes to make themselves look almost invisible. They usually forage alone, but they may roost right beside another Madagascar nightjar to help them blend in. These birds are monogamous when breeding, and they’re highly territorial toward unfamiliar birds.

6. Madagascar Tree Boa

Madagascar tree boa close-up
  • Scientific Name: Sanzinia madagascariensis
  • Habitat: Forests of Madagascar
  • Size: 4 to 5 feet long
  • Diet: Birds, bats, small mammals

Madagascar tree boas change colors throughout their lives. They start out with bright red scales, but they turn green as they age. Pregnant boas have scales that are almost black. These reptiles are nocturnal, so even though they live near humans, they’re not commonly seen. They’re not venomous or aggressive, so they don’t pose a threat. These snakes may sleep in trees, but they hunt on the ground.

7. Magellanic Penguin

Group of magellanic penguins
  • Scientific Name: Spheniscus magellanicus
  • Habitat: Coasts of southern South America
  • Size: 6 to 14 pounds
  • Diet: Small fish, squid, crustaceans

Like other penguin species, these birds are social. They may be found in groups of up to 400,000 penguins. They can survive in warm areas where temperatures reach 68 degrees Fahrenheit. If they get too hot, they can shed some of their feathers to help them cool down. Each penguin has a unique call, so females can listen to the calls of their mates to find them in a crowd. When hunting, they can swim up to 15 miles per hour underwater.

8. Magellanic Woodpecker

Magellanic woodpecker foraging
  • Scientific Name: Campephilus magellanicus
  • Habitat: Forests of southern Chile and southwestern Argentina
  • Size: 14 to 18 inches long
  • Diet: Insects, insect larvae, nuts, seeds, sap

Males of this species have vibrant red feathers on their heads while females have mostly black feathers with a few red-orange ones near their beaks. They’re often seen hitting their beaks on wood in search of grubs. They usually forage on live trees, but they can sometimes find food in broken branches and rotting wood too. They build nests in tree cavities that they dug.

9. Magnificent Rabbitfish

Magnificent rabbitfish by coral reef
  • Scientific Name: Siganus magnificus
  • Habitat: The eastern Indian Ocean
  • Size: 7.9 to 9.4 inches
  • Diet: Algae, small invertebrates

These fish can use fin movements to express themselves. Their dorsal and anal fins lie flat when the fish is swimming, but the fish can raise the fan-like fins to threaten other creatures. They typically stay near coral reefs so it’s easy for them to find shelter when needed. Juvenile magnificent rabbitfish usually keep to themselves, but adults often travel in pairs.

10. Magnificent Tree Frog

Magnificent tree frog clinging to branch
  • Scientific Name: Litoria splendida
  • Habitat: Caves and rock crevices of northwestern Australia
  • Size: 4 to 4.2 inches long
  • Diet: Large insects, earthworms, spiders

Magnificent tree frogs often have a lump on their heads, which is a secret defense against predators. They can hold a poisonous liquid in a sac inside their heads to deter large animals. However, their poison isn’t harmful to humans. Despite being called tree frogs, these amphibians spend more time climbing on rocks than trees. They’re nocturnal, so during the day, they seek out dark, moist areas to hide in.

11. Magnolia Warbler

Magnolia warbler on tree branch
  • Scientific Name: Setophaga Magnolia
  • Habitat: Across eastern North America
  • Size: 4.3 to 5.1 inches long
  • Diet: Insects, insect larvae, fruit

Magnolia warblers love eating caterpillars, which they look under leaves to find. They can thrive in a variety of habitats, but they prefer areas with dense vegetation so it’s harder for predators to find them. Males are very vocal, and they can be heard best during dusk and dawn. Males and females usually live separately, but they come together during their breeding season. Their nests are usually built quickly, causing them to look messy.

12. Magpie Goose

Magpie goose standing in the grass
  • Scientific Name: Anseranas semipalmata
  • Habitat: Open wetlands of Australia
  • Size: 4.4 to 6.6 pounds
  • Diet: Grass, seeds, bulbs

Magpie geese are the last living species of the family Anseranatidae. They used to be widespread across Australia, but the drainage of wetlands has decreased their breeding areas. They’re unique from other geese species because they have a knob on their heads and only semi-webbed feet. These geese mate for life, but some males mate with two female geese that are related. Those two females may share the nest that the male constructed for them.

13. Mahi Mahi

Mahi Mahi fish underwater
  • Scientific Name: Coryphaena hippurus
  • Habitat: Tropical, subtropical, and temperate seas worldwide
  • Size: 2.8 to 4.6 feet long
  • Diet: Fish, crabs, squid

Mahi Mahi, also known as dolphin fish, are beautiful creatures to encounter due to their shimmering scales. They’re not related to dolphins, but their appearance and behaviors sometimes resemble the intelligent mammals. They often swim in front of ships like dolphins do, and they can swim almost 60 miles per hour. These fish are often caught by humans because their meat is known for being flavorful and healthy.

14. Maine Coon

Maine coon cat close up
  • Scientific Name: Felis catus
  • Habitat: Domesticated
  • Size: 8 to 18 pounds
  • Diet: Domestic cat food

Maine Coons are the largest domesticated cats, but they’re described as “gentle giants.” In some ways, they have a personality closer to a dog than a cat. They love playing, and some even enjoy walking on a leash. Unlike most domestic cats, they rarely meow, but instead, they make a chirping sound. They have water-resistant fur, so they’re not as bothered by water as other felines are.

15. Malabar Gliding Frog

Malabar gliding frog close-up
  • Scientific Name: Rhacophorus malabaricus
  • Habitat: Across the Western Ghats of India
  • Size: About 4 inches long
  • Diet: Insects

Malabar gliding frogs spend most of their time in trees. As the species name implies, these frogs can glide between trees by extending the webbing between their toes when jumping. They can glide distances up to 115 times the length of their bodies. They communicate with a wide variety of croaking vocalizations, but they make the most calls during their mating season. Breeding is the one time each year these frogs move from the trees to stagnant water.

16. Malawi Eyebiter

Malawi eyebiter in open waters
  • Scientific Name: Dimidiochromis compressiceps
  • Habitat: Shallow waters of Lake Malawi, Lake Malombe, and the upper Shire River
  • Size: Up to 9.8 inches long
  • Diet: Small fish, krill, mussels, shrimp

The Malawi eyebiter gets its unique name from its hunting tactics. These fish hide in crevices while they wait for smaller fish to swim past. Then, they ambush their prey while aiming for the eyes in an attempt to weaken it. When they eat their prey, they usually swallow it tail-first. Despite ambushing small creatures, they’re not territorial toward fish of the same size or larger.

17. Malayan Civet

Malayan civet walking
  • Scientific Name: Viverra tangalunga
  • Habitat: Rainforests and tropical jungles of Malay Peninsula
  • Size: 7 to 24 pounds
  • Diet: Rodents, snakes, frogs, insects

Malayan civets communicate using scents, so they can release a musk from their perianal glands. They may also release the musk when threatened. People seek out this musk because it can be used for medicinal purposes and perfumes. Instead of killing the civets, people can tame them to collect their musk. Malayan civets spend most of their time on the ground, but they can climb trees if needed.

18. Malayan Flying Lemur

Malayan flying lemur clinging to tree
  • Scientific Name: Galeopterus variegatus
  • Habitat: Tropical rainforests of southeastern Asia
  • Size: 2 to 2.9 pounds
  • Diet: Fruits, flowers, buds, nectar, sap

Malayan flying lemurs, also known as Sunda flying lemurs, are a mysterious species. Little research has been done on them because they’re difficult to raise and breed in captivity. They spend most of their time in tree canopies, and they may lick the bark to obtain essential nutrients. They’re excellent climbers, but they struggle to move on the ground. So, they glide to get from one tree to another. They can glide up to 330 feet without descending too much.

19. Malayan Krait

Malayan krait slithering
  • Scientific Name: Bungarus candidus
  • Habitat: Moist forests of southeastern Asia
  • Size: About 3.5 feet long
  • Diet: Smaller snakes, lizards, frogs, mice

Malayan kraits are one of the world’s most dangerous snakes. They have venom that’s made up of neurotoxins, so the venom attacks the nervous system. Without treatment, a person will likely die within 24 hours of being bitten. These snakes are nicknamed “five-step snakes” because people claim that someone can’t walk more than five steps after getting bitten. In reality, the bite itself is nearly painless, so the venom can do a lot of damage before the person realizes it.

20. Malayan Night Heron

Malayan night heron in forest
  • Scientific Name: Gorsachius melanolophus
  • Habitat: Forested areas from India to the east Indies
  • Size: About 19 inches long with a 38-inch wingspan
  • Diet: Earthworms, frogs, fish

These are medium-sized herons that are usually solitary in moist forests. Their feathers are mostly light brown, but when they’re ready to breed, they will develop a bright blue patch around their eye. Immature herons and non-breeding adults will not have any blue on their faces. They’re most active at night, but they may forage during the day too. They prefer prey with soft exteriors that they can swallow whole.

21. Malayan Porcupine

Malayan porcupine standing still
  • Scientific Name: Hystrix brachyura
  • Habitat: Forests of southeastern Asia
  • Size: About 18 pounds
  • Diet: Roots, tubers, bark, fruits

Malayan porcupines eat a plant-based diet, so they have strong jaws for breaking seeds and nuts. Even though they don’t eat meat, they’ve been observed gnawing on bones. They live with up to 10 family members in a series of underground burrows. The same burrows may be used for generations. Not many animals hunt these porcupines because if they’re threatened, they will charge backward with their quills raised.

22. Malayan Softshell Turtle

Malayan softshell turtle laying in water
  • Scientific Name: Dogania subplana
  • Habitat: Rocky streams of southeastern Asia
  • Size: About 14 inches long
  • Diet: Mollusks

Despite having soft exteriors, these turtles have powerful jaws that they can use to break through the shells of mollusks. Thus, they can also deliver a powerful bite if threatened. They spend time laying in shallow water with their heads sticking out because their coloring helps them camouflage. When they’re young, these turtles have a few round spots on their shells, but those markings disappear as they age.

23. Malayan Tapir

Malayan tapir sniffing grass
  • Scientific Name: Tapirus indicus
  • Habitat: Swamps and forests of southeastern Asia
  • Size: 550 to 700 pounds
  • Diet: Leaves, shoots, aquatic plants, buds

Malayan tapirs are sometimes nicknamed “Oreo” tapirs due to their white patch surrounded by black. Their unique coloring helps them hide from predators because the white breaks up the tapir’s outline when hiding in the forest’s shadows. The barrel-shaped bodies of these mammals help them crash through branches to escape predators. Their unique snout is similar to a short version of an elephant trunk. It can be used for following scents and grabbing leaves.

24. Malayan Tiger

Malayan tiger surrounded by plants
  • Scientific Name: Panthera Tigris Jacksoni
  • Habitat: Jungles of the Malayan Peninsula
  • Size: 176 to 330 pounds
  • Diet: Deer, wild boar

Every Malayan tiger has a unique stripe pattern, similar to how every human has a unique fingerprint. These felines are fierce predators that mostly hunt at night. Their only predators are humans, but male tigers may harm each other if they fight over territories. Tigers will leave claw marks and a unique scent behind to mark their territories. When other tigers smell that scent, they will avoid it. Malayan tigers can communicate with each other by making puffing, growling, and roaring sounds.

25. Mallard

Male and female mallard ducks
  • Scientific Name: Anas platyrhynchos
  • Habitat: Freshwater across North America, Europe, and Asia
  • Size: 1.6 to 3.5 pounds
  • Diet: Vegetation, insects, worms, snails

Mallards are what most people think of when they imagine a duck because these birds can be found near freshwater around the world. They’re one of the few duck species that can be domesticated, and almost all domestic duck breeds are descended from them. They sometimes breed with ducks of other species, causing an excess of hybrids. This is a concern for rare species like the Hawaiian duck, which may be replaced by hybrids in the near future.

26. Maltese

Maltese with bows in hair
  • Scientific Name: Canis familiaris
  • Habitat: Domesticated
  • Size: 5 to 9 pounds
  • Diet: Domestic dog food

Maltese are one of the oldest dog breeds, existing for over 2,500 years. These little dogs were bred as companions, and like many similar breeds, they were known for warming the laps of royalty. While most Maltese show dogs have white hair that drags on the ground like a mop, it’s more common for pet Maltese to have short coats. They’re popular for families with dog allergies because they barely shed. However, they require a lot of brushing to keep their coats silky.

27. Mamushi Snake

Mamushi snake curled up
  • Scientific Name: Gloydius blomhoffii
  • Habitat: Woodlands, meadows, and marshes of Japan
  • Size: 17 to 32 inches long
  • Diet: Rodents, frogs, birds, lizards, insects

The Mamushi snake is also known as the Japanese moccasin or the Japanese pit viper. They’re highly venomous and dangerous because they have highly potent venom that can cause severe swelling. These snakes usually stay away from humans, but they may go after fingers and toes if they mistake them for prey. Even with treatment, some people don’t survive these bites. Mamushi snakes are ambush predators that will hide among leaf litter and then lunge at animals that pass.

28. Mandarin Rat Snake

Mandarin rat snake close up
  • Scientific Name: Euprepiophis mandarinus
  • Habitat: Forests and farmlands of China, Taiwan, Burma, and Vietnam
  • Size: 3 to 5 feet long
  • Diet: Rodents

Mandarin rat snakes are calm, docile reptiles without any venom. Thus, they’re commonly kept as pets. However, they’re a big commitment because they can live up to 21 years and need to be fed mice. In the wild, these snakes are shy and avoid people whenever possible. They’re active during the day and hide in burrows at night. Even though they’re not venomous, they still have sharp teeth that can break skin if they’re threatened.

29. Mandrill

Colorful mandrill face
  • Scientific Name: Mandrillus Sphinx
  • Habitat: Rainforests of west central Africa
  • Size: 25 to 80 pounds
  • Diet: Fruit, roots, insects

Mandrills are one of the few colorful primates. They stand out because of the blue and red pigments around their nose. During mating season, females are most likely to be attracted to the males with the most vibrant colors. These mammals usually feed on plants, and they can store extra food in their cheek pouches like a chipmunk can. When mandrills open their mouths, they show off their sharp canine teeth, which they can use for self-defense.

30. Maned Sloth

Maned sloth climbing in tree
  • Scientific Name: Bradypus torquatus
  • Habitat: The Atlantic coastal rainforest of Brazil
  • Size: 9 to 22 pounds
  • Diet: Tree leaves

These creatures are a species of three-toed sloth. They spend most of their time in the trees because they only feed on leaves. When they eat leaves, it benefits the ecosystem because they help disperse seeds. They only climb down from the trees to defecate, and their slow motions prevent predators from detecting them as they climb up and down. They can rotate their necks up to 270 degrees to look for food.

31. Maned Wolf

Maned wolf standing in grass
  • Scientific Name: Chyrsocyon brachyurus
  • Habitat: Grasslands and forests across South America
  • Size: 44 to 66 pounds
  • Diet: Fruits, vegetables, rodents, rabbits, insects

Maned wolves have much longer legs than any other canines, likely to help them see above tall grass. They’re solitary creatures, so they don’t hunt in packs like similar-looking species. These creatures aren’t true wolves or true foxes, but instead, they’re their own unique species. They mark their territories with urine, but their urine has a strong odor that humans compare to a skunk’s stench. A big portion of their diet consists of fruits and vegetables, so they only hunt small animals for meat.

32. Mangrove Snake

Mangrove snake ready to attack
  • Scientific Name: Boiga dendrophila
  • Habitat: Forests of southeastern Asia
  • Size: 6 to 7 feet long
  • Diet: Small mammals, reptiles, birds

Mangrove snakes are venomous, but their venom isn’t very strong. It takes time for venom to be released, so these snakes have to chew on their victims to release more venom. Thus, most humans walk away with minor swelling. However, these snakes look like banded kraits, which are very dangerous snakes. Despite their name, mangrove snakes are more common in lowland forests than mangrove forests.

33. Mantled Howler Monkey

Mantled howler monkey clinging to tree
  • Scientific Name: Alouatta palliata
  • Habitat: Lowland and montane rainforests from southern Mexico to northern South America
  • Size: 11 to 15 pounds
  • Diet: Fruits, flowers, buds, leaves

Mantled howler monkeys live up to their name by producing howling calls that can be heard up to three miles away. These sounds usually occur at dusk and dawn. Despite living in rainforests, these monkeys rarely drink water directly. Instead, they get all the moisture they need from the plants they eat. They spend almost all their time in the trees, and they can use their prehensile tail to grab onto branches if needed.

34. Marabou Stork

Marabou stork surrounded by plants
  • Scientific Name: Leptoptilos crumenifer
  • Habitat: Savannas, grasslands, and swamps of Sub-Saharan Africa
  • Size: 10 to 20 pounds, about 5 feet tall
  • Diet: Fish, insects, carrion, frogs, lizards, rodents

Marabou storks are the world’s largest storks. These massive birds aren’t afraid to live near people because they will sometimes eat the garbage humans leave behind. However, if people invade their personal space, they may act aggressively. These birds don’t have voice boxes, so they click their bills to communicate. They will eat almost anything that will fit in their bills, especially smaller animals.

35. Marbled Electric Ray

Marbled electric ray on rocky ocean floor
  • Scientific Name: Torpedo marmorata
  • Habitat: Rocky reefs of the eastern Atlantic Ocean
  • Size: Up to 39 inches long
  • Diet: Small fish

Marbled electric rays are ambush predators that usually stay along the ocean floor. They don’t have venomous barbs like other rays, but instead, they can use specialized organs to produce an electric discharge. When small fish swim past, the ray might jump out at them and stun them with its shocks. The rays can produce up to 200 volts, which can kill some fish. They can use their electric organs the moment they’re born.

36. Marbled Newt

Marbled newt on rocks
  • Scientific Name: Triturus marmoratus
  • Habitat: Near water in southern Europe
  • Size: 5 to 6.5 inches long
  • Diet: Insects, insect larvae, worms

Marbled newts spend their time switching between land and water, so they’re highly adaptable. When rainfall is high, they spend more time in the water, but during droughts, they’re primarily terrestrial. These newts always return to the water to breed because females deposit their eggs on aquatic leaves. During the mating season, males prefer large females and females prefer males with large crests.

37. Marbled Polecat

Marbled polecat hiding behind plant
  • Scientific Name: Vormela peregusna
  • Habitat: Open deserts and rocky areas from southeastern Europe to China
  • Size: 13 to 14 inches long
  • Diet: Small mammals, birds, lizards, insects

Marbled polecats will hunt just about any animal that’s small enough for them to eat. However, they have bad eyesight, so they rely on their sense of smell to locate prey. They’re usually very quiet, but they will shriek if they think they’re in danger. They can also release a foul-smelling substance from their anal glands to defend themselves. These creatures are always on the move, so they rarely stay in the same shelter more than once.

38. Marbled Salamander

Marbled salamander on moss
  • Scientific Name: Ambystoma opacum
  • Habitat: Deciduous woodlands of southeastern United States
  • Size: 3.5 to 4.75 inches long
  • Diet: Worms, slugs, snails, spiders, insects

Marbled salamanders are a type of mole salamander, meaning they’re stocky salamanders that spend most of their time underground. They will dig their own burrows and protect their space from other salamanders. They have poison glands on their stubby tails that will release a foul taste if a predator tries to eat them. Their poison can make small animals sick, but it will not harm humans. Thus, these amphibians are sometimes kept as pets.

39. Margay

Margay cat curled up
  • Scientific Name: Leopardus wiedii
  • Habitat: Tropical forests from central Mexico to central South America
  • Size: 5 to 9 pounds
  • Diet: Birds, small mammals, reptiles, eggs, fruit

Margays are the size of domesticated cats, but they’re colored like big cats. They have visible spots on their fur as soon as they’re born. They’re agile wild felines, and their ankles can rotate up to 180 degrees to help them climb and jump on trees. Their extra flexibility allows them to climb down trees head-first if needed. These felines don’t stalk prey, but instead, they hide and wait to ambush it.

40. Marginated Tortoise

Marginated tortoise sitting on rock
  • Scientific Name: Testudo marginata
  • Habitat: Dry habitats of Greece, Italy, and the Balkan Islands
  • Size: 10 to 15.7 inches long
  • Diet: Grass, flowers, fruits

Marginated tortoises are the largest tortoises in Europe, even though they only weigh up to 11 pounds. They usually live anywhere from 100 to 140 years. These reptiles are solitary creatures, and they can be territorial around other tortoises in the wild. When kept as pets, they’re often described as calm. They have dark shells so they can absorb enough heat to stay warm. During the coldest parts of winter, they go into hibernation.

41. Marine Iguana

Marine iguana by the water
  • Scientific Name: Amblyrhynchus cristatus
  • Habitat: Rocky shorelines of the Galapagos Islands
  • Size: 2 to 4 feet long, 3 to 24 pounds
  • Diet: Marine algae, seaweed

Marine iguanas can vary greatly in size because the ones living on the larger islands grow much longer than the ones living on smaller islands. If there’s a lack of food available, these reptiles can shrink their body size up to 20% to survive. As their name implies, marine iguanas swim in shallow water to find food. They’re the only lizard species known to spend time in the ocean. They can stay underwater for up to 10 minutes at a time.

42. Marine Otter

Marine otter resting on land
  • Scientific Name: Lontra felina
  • Habitat: Pacific Ocean’s coast on North and South America
  • Size: 7 to 13 pounds
  • Diet: Fish, crabs, shrimp, mollusks

Marine otters are the only members of the weasel family, besides sea otters, that spend time in the ocean. Sea otters spend their whole lives in saltwater, but marine otters regularly come to the shore. Marine otters primarily head into the ocean to hunt, diving 98 to 131 feet to catch prey. When they dive, they can seal their noses and ears for protection. Their fur is thicker than almost any other mammal, with up to a million hairs per square inch.

43. Markhor

Markhor standing on mountain
  • Scientific Name: Capra falconeri
  • Habitat: Forested areas of the Himalayan Mountain Range
  • Size: 71 to 240 pounds
  • Diet: Grass, leaves, herbs

Markhors are the largest animals in the goat family, and they can be distinguished by their long, twirly horns. Males have significantly longer horns than females. Their horns have several purposes, including digging for food, scraping bark off trees, and fighting with other markhors. You can tell how old a markhor is by looking at how many rings are in their horns, similar to a tree. They live at high altitudes, anywhere between 1,600 and 11,000 feet.

44. Marsh Deer

Marsh deer wading in swamp
  • Scientific Name: Blastocerus dichotomus
  • Habitat: Marshy areas of central South America
  • Size: 220 to 330 pounds
  • Diet: Aquatic plants

This is the largest deer species in South America. Their wide hooves have elastic tissue to make swimming easier for them. They usually seek out marsh areas with dense vegetation because it provides them with food and protection from predators. During dry seasons, marsh deer may migrate to find more suitable environments. Most of them are solitary, but some form groups of up to six deer.

45. Marsh Frog

Marsh frog on lilypad
  • Scientific Name: Pelophylax ridibundus
  • Habitat: Marshes, ponds, and streams of Europe and parts of Asia
  • Size: 4.7 to 7 inches long
  • Diet: Insects, spiders, slugs

Marsh frogs spend most of their time in or near water. If they sense danger, they will swim out to deeper water if possible. They’re active both day and night, but they hibernate in the winter. When hibernating, they burrow in the mud in a body of water to prevent them from freezing during cold temperatures. They’re excellent at swimming and jumping, making it difficult for predators to catch them. They can jump as far as ten feet.

46. Marsh Owl

Marsh owl perched on branch
  • Scientific Name: Asio capensis
  • Habitat: Moist grasslands of southern Africa
  • Size: 12 to 15 inches long
  • Diet: Small rodents, birds, insects

Marsh owls spend most of their time alone or in pairs. They’re highly territorial, especially during their breeding season. Like most owl species, they’re nocturnal, but they may be active during cloudy days. They are fairly quiet, but you may hear them make soft, hoarse calls. When hunting, they fly close to the ground and scoop up whatever small animals they can find. They may catch flying insects in mid-air.

47. Marsh Rabbit

Marsh rabbit sitting in the grass
  • Scientific Name: Sylvilagus palustris
  • Habitat: Fresh and brackish marshes of southeastern United States
  • Size: 14 to 16 inches long
  • Diet: Woody and semi-woody plants

Marsh rabbits are strong swimmers, so they’re usually found near water. If threatened, they may dive underwater to escape predators. They feed on the plants that grow in wetlands, and they’re most active at night. Young marsh rabbits can forage by themselves at only four weeks old. These rabbits are often confused with eastern cottontails, but marsh rabbits are smaller with less fur.

48. Martial Eagle

Martial Eagle perched on branch
  • Scientific Name: Polemaetus bellicosus
  • Habitat: Open grasslands of Sub-Saharan Africa
  • Size: About 14 pounds, over 6-foot wingspan
  • Diet: Medium-sized mammals, birds, reptiles

Martial eagles are the largest and strongest eagle species in Africa. It’s believed that these birds can knock a grown man off his feet or break his arm. They spend most of their time soaring so high in the sky that you can’t see them without binoculars. They can fly so far away because their eyesight is four times better than a human’s. These massive birds bathe themselves daily to keep their feathers clean.

49. Masked Palm Civet

Masked palm civet in grass
  • Scientific Name: Paguma larvata
  • Habitat: Forests of southern Asia
  • Size: 3 to 10 pounds
  • Diet: Rodents, birds, snakes, fruit

Masked palm civets spend most of their time in trees, and they’re most active at night. They mostly keep to themselves, but they will act aggressively if needed. If they feel threatened, they can spray a foul-smelling substance to drive predators away. They build nests in the highest levels of trees and sleep there during the day. They can use their long tails to help them cling to tree branches.

50. Masked Shining Parrot

Masked shining parrot perched on plant
  • Scientific Name: Prosopeia personata
  • Habitat: Tropical or subtropical moist lowland forests of Fiji
  • Size: 18.3 to 19 inches long
  • Diet: Seeds, fruits

Masked shining parrots go by many names, including masked musk parrots and yellow-breasted shining parrots. Juvenile parrots have similar coloring to adults, but their face masks darken as they age. These birds are very talkative, making a variety of squawks and shrieks. They often repeat their high-pitched notes to warn others of danger. When roosting, they also make a series of cackling sounds.

51. Massasauga

Massasauga snake curled up
  • Scientific Name: Sistrurus catenatus
  • Habitat: Open canopy wetlands in parts of North America
  • Size: About 2 feet long
  • Diet: Small mammals, lizards, frogs

These are venomous rattlesnakes, but they’re shy, so humans are rarely bitten by them. They only act aggressively if they’re unable to escape a threat. However, males may also fight each other over a female. They rarely make rattling sounds because they prefer to stay as still as possible to avoid danger. How often they reproduce depends on how much food they have access to, but they usually produce young every one to three years.

52. Mealworm

  • Scientific Name: Tenebrio molitor
  • Habitat: Dark, moist areas worldwide
  • Size: Up to 1.5 inches
  • Diet: Decaying plants, stored grains, dead insects

Most people recognize mealworms as food to give to reptiles and amphibians, but those worms actually turn into beetles. Keeping mealworms refrigerated prevents them from transitioning to their final stage. In the wild, these insects are pests because the beetles lay their eggs in grain containers, making them hard to spot. The beetles can fly, which is how their population spread so quickly.

53. Mediterranean House Gecko

Mediterranean house gecko up close
  • Scientific Name: Hemidactylus turcicus
  • Habitat: Coastal areas of Mediterranean countries
  • Size: 4 to 5 inches long
  • Diet: Insects

Mediterranean house geckos are native to the Mediterranean region, but they have become an invasive species in other areas of the world, such as the southern United States. They’re most active at night, and they retreat to shaded areas during the day to rest. They lay their eggs in dark, moist areas, such as under stones or in wood crevices. When threatened, these reptiles may let out a high-pitched call that resembles a bird chirping.

54. Mediterranean Monk Seal

Mediterranean monk seal underwater
  • Scientific Name: Monachus monachus
  • Habitat: The Mediterranean Sea and eastern Atlantic Ocean
  • Size: 550 to 700 pounds
  • Diet: Bony fish, cephalopods, crustaceans

Sadly, Mediterranean monk seals are a critically endangered species. There are less than 600 individuals remaining today. These seals used to give birth on open beaches, but due to human disturbances, they were forced to raise their young in remote marine caves instead, where the moms can keep their pups out of sight. They primarily stay in shallow areas, and they’re opportunistic hunters that will capture whatever prey is accessible.

55. Mediterranean Moray

Mediterranean moray face
  • Scientific Name: Muraena helena
  • Habitat: Coastal waters of the eastern Atlantic Ocean
  • Size: Up to 4.9 feet long
  • Diet: Fish, crayfish, cephalopods

Mediterranean morays are solitary and highly territorial. They hide in crevices anywhere from 16 to 262 feet below the water’s surface. They usually hunt at night, and they will snatch any small sea creatures that swim by. If necessary, they will also feed on dead animals. They can cause a dangerous bite for humans because of their sharp teeth and mildly toxic skin.

56. Meerkat

Group of meerkats on rock
  • Scientific Name: Suricata suricatta
  • Habitat: Deserts of southern Africa
  • Size: 1.4 to 2.1 pounds
  • Diet: Insects, spiders, centipedes

Meerkats are social animals that live in groups of up to 30. They will often stand on their hind legs to look for danger so they can warn the others. They have great eyesight, so they can see a predator coming from miles away. Meerkats have a lot of adaptations to help them survive in desert habitats. First of all, they don’t need to drink any water because they get enough moisture from the food they eat. They’re also immune to the venom of many snake species.

57. Mekong Giant Catfish

Mekong giant catfish up close
  • Scientific Name: Pangasianodon gigas
  • Habitat: The Mekong River
  • Size: Up to 10 feet long
  • Diet: Zooplankton, algae, aquatic plants

The Mekong giant catfish is the largest fish that exists in only freshwater. They have huge mouths with eyes below their mouths to help them forage for zooplankton and plant matter. Their skin is completely smooth with no scales at all. These fish used to be popular for human consumption, but overfishing threatened their population, so now it’s illegal to hunt this species in certain areas.

58. Merriam’s Chipmunk

Merriam's chipmunk on tree branch
  • Scientific Name: Tamias merriami
  • Habitat: Forests of central and southern California
  • Size: 5.5 to 9 inches long
  • Diet: Seeds, nuts

Most of these chipmunks don’t hibernate because of California’s warm weather, but individuals living at high elevations may be an exception. They spend most of their time alone, but they make a variety of different sounds to communicate with each other, including warning calls. These rodents mostly eat seeds, nuts, and other plant parts, but they may consume insects and small lizards in rare cases.

59. Messmate Pipefish

Messmate pipefish face close up
  • Scientific Name: Corythoichthys haematopterus
  • Habitat: Tropical waters of the Indo-west Pacific region
  • Size: Up to 7.8 inches long
  • Diet: Plankton, small crustaceans, worms

Messmate pipefish spend most of their time in shallow, sandy areas. Their stripes and tan skin help them blend into the substrate below them. They can emit unique colors when exposed to different types of light, which is a process known as biofluorescence. Researchers believe these creatures may use that trait to camouflage or communicate with other pipefish.

60. Mexican Alligator Lizard

Mexican alligator lizard on rock
  • Scientific Name: Abronia graminea
  • Habitat: Cloud forests of Mexico
  • Size: 6 to 12 inches long
  • Diet: Insects, worms

Mexican alligator lizards live in trees, and they can be found as far as 130 feet above the ground. As juveniles, these lizards have tan scales, but they gradually turn vibrant green as they age. In captivity, the lizards become teal instead of green, but researchers are unsure why. One prediction is that they need natural sunlight to maintain their vibrant green color. Sadly, these reptiles are currently endangered because of illegal poaching.

61. Mexican Black Kingsnake

Mexican black kingsnake in the grass
  • Scientific Name: Lampropeltis getula nigrita
  • Habitat: Desert areas from Mexico to Arizona
  • Size: 3 to 4 feet
  • Diet: Rodents, eggs, lizards, snakes

These snakes are a subspecies of the common kingsnake, and they’re a common pet because of their beautiful black scales. They don’t have venom, so they rarely harm humans. They’re docile snakes that don’t bite unless it’s their only option. When hunting, they kill their prey by constricting it until it dies. These snakes are capable of climbing trees and gliding across water.

62. Mexican Fireleg Tarantula

Mexican fireleg tarantula standing still
  • Scientific Name: Brachypelma boehmei
  • Habitat: Dry scrublands of southern Mexico
  • Size: 5 to 6 inches long
  • Diet: Large insects, small lizards

Mexican fireleg tarantulas don’t build webs to catch their prey, but instead, they hunt it down. If they feel threatened, they will flick their hairs at a creature, which can cause a stinging sensation. They’re also venomous, but they rarely bite. Despite their dangerous defense mechanisms, many people keep these critters as pets due to their bold coloring and docile behaviors. Some people describe them as “living rocks” because they sometimes stand in the same spot for days.

63. Mexican Hairy Dwarf Porcupine

Mexican hairy dwarf porcupine climbing tree
  • Scientific Name: Sphiggurus mexicanus
  • Habitat: High-elevation forests of Mexico and Central America
  • Size: 12.6 to 18 inches long
  • Diet: Seeds, fruits, leaves, flowers

Mexican hairy dwarf porcupines, also known as Mexican tree porcupines, live in forest canopies. They use their prehensile tails to help them grab onto branches as they climb. They almost always retreat to the same hollow tree for shelter. Thus, they often have a foul odor associated with them because their droppings accumulate in their hiding place. They’re usually solitary, but during their breeding season, they will scream and yowl to communicate with each other.

64. Mexican Musk Turtle

Mexican musk turtle swimming underwater
  • Scientific Name: Staurotypus triporcatus
  • Habitat: Slow-moving freshwater of Mexico and Central America
  • Size: Up to 15 inches long
  • Diet: Aquatic invertebrates, fish, carrion

Mexican musk turtles got their name because they can release a musky smell from the glands near the back of their shell. They use the unpleasant scent to deter predators. They don’t like to be handled by humans, and they may act aggressively if bothered. They have lots of blood cells in their shells, so they can feel when something is touching them. They have excellent vision, which helps them hunt down their prey while underwater.

65. Mexican Prairie Dog

Mexican prairie dog peeking out of burrow
  • Scientific Name: Cynomys mexicanus
  • Habitat: Plains of northern Mexico
  • Size: 3 to 7 pounds
  • Diet: Herbs, grass

These burrowing mammals are considered agricultural pests, so sadly, they’re endangered because humans have tried to control them too much. They live in areas with rock-free soil at elevations between 5,200 and 7,200 feet. They have an elaborate communication method, which consists of various high-pitched sounds. If they sense danger, they will make an alarm sound before running away at up to 35 miles per hour.

66. Mexican Tetra

Blind Mexican tetra underwater
  • Scientific Name: Astyanax mexicanus
  • Habitat: The lower Rio Grande, Pecos, and Nueces rivers
  • Size: Up to 4.7 inches long
  • Diet: Crustaceans, insects, worms

Mexican tetras are also known as blind cave fish. Research shows that these fish once had eyes, but cellular degeneration in the eye lens over time led to only blind fish being produced. The lack of sun exposure also caused them to lose skin pigment. Even with no sight, these fish can still find their way around using lateral line organs to detect movement and vibrations.

67. Midget Faded Rattlesnake

Midget faded rattlesnake hiding in wood
  • Scientific Name: Crotalus concolor
  • Habitat: Across the Green River Formation of Wyoming, Colorado, and Utah
  • Size: 2 to 3 feet long
  • Diet: Lizards, mice, birds

Despite their small size, these rattlesnakes are highly dangerous. They have highly potent venom, but they rarely bite unless provoked. Their venom can attack the nervous system and damage muscle tissue. Their bodies are the same color as the sand around them, so they can sneak up on prey and hide from predators at the same time. When the females are about to reproduce, they share basking spots and dens with each other.

68. Military Macaw

Military macaw by flowers
  • Scientific Name: Ara militaris
  • Habitat: Humid lowland forests from Mexico to Argentina
  • Size: 27.5 to 33.5 inches long
  • Diet: Seeds, nuts, fruits

Military macaws got their name because their mostly green plumage resembles a military parade uniform. These birds love to be the center of attention, so they’re very vocal and can mimic human voices. They’re social, living in groups of up to 20 birds, but bonded pairs stay closest together. These birds mate for life, and when they fly beside their partner, their wings often touch. They can fly up to 35 miles per hour.

69. Milk Snake

Milk snake on rock
  • Scientific Name: Lampropeltis triangulum
  • Habitat: Arid, rocky areas of eastern North America
  • Size: 2 to 3 feet long
  • Diet: Rodents, reptiles, eggs

Milk snakes look like they would be dangerous reptiles, but they’re generally harmless to humans because they’re not venomous. Their vibrant colors help deter predators. When it comes to food, they’re not picky. They’ll eat almost any animals smaller than them, including other snakes. There are 24 subspecies of milk snakes, each with a unique appearance.

70. Mimic Poison Frog

Mimic poison frog perched on leaf
  • Scientific Name: Ranitomeya imitator
  • Habitat: Rainforests of northeastern Peru
  • Size: About 0.5 inches long
  • Diet: Fruit flies, ants, mites, beetles

Mimic poison frogs are a species of poison dart frogs that can release toxic secretions when threatened. However, their toxins are only mild compared to similar species. So, they got their name because they’re often mistaken for more dangerous poison dart frogs. Like many poisonous frogs, they don’t produce toxicity when kept in captivity. They are skilled climbers, and they’re most active during the day.

71. Mink Frog

Mink frog resting in the water
  • Scientific Name: Lithobates septentrionalis
  • Habitat: Near lakes and rivers in the northeastern United States
  • Size: 2 to 3 inches long
  • Diet: Insects, spiders, snails, aquatic invertebrates

Mink frogs can be distinguished from similar species because of the dark blotches on their green skin. They have a musky smell similar to one a mink releases, which is how the species got its name. They spend most of their time in the water, and in the winter, they burrow in the muddy substrate at the bottom of lakes and rivers to hibernate. They most commonly make noise after midnight.

72. Mirror Butterflyfish

Mirror butterflyfish in dark waters
  • Scientific Name: Chaetodon speculum
  • Habitat: Coastal reefs of the Indo-Pacific region
  • Size: Up to 7 inches long
  • Diet: Coral polyps, small invertebrates

In the wild, these fish can be found near coral reefs between 10 and 100 feet below sea level. However, they’re often kept in captivity as well due to their unique coloring. They primarily feed on coral polyps, so there should be living corals in aquariums for them. If they’re given an alternate diet in captivity, health problems could arise. These fish are docile, so they shouldn’t be kept with larger, more aggressive fish.

73. Mississippi Kite

Mississippi kite in tree
  • Scientific Name: Ictinia mississippiensis
  • Habitat: Open woodlands from the United States to South America
  • Size: 13 to 15 inches long
  • Diet: Insects, rodents, snakes, small birds

Mississippi kites primarily catch flying insects, which they hunt down in mid-flight. They migrate long-distance, usually from the United States to northern South America. They have a unique call that can be mistaken for a high-pitched squeaky toy. They roost together in large flocks rather than securing their own territory. They usually migrate in groups of 20 to 30 birds.

74. Mojave Rattlesnake

Mojave rattlesnake close-up
  • Scientific Name: Crotalus scutulatus
  • Habitat: Desert mountain slopes in the Mojave Desert
  • Size: 2 to 4 feet long
  • Diet: Rodents, rabbits, lizards, toads, birds

Mojave rattlesnakes, also known as Mojave greens, are one of the most venomous rattlesnakes in the world. Their venom can shut down a person’s central nervous system, cause blood clotting, and damage tissues and organs with only one bite. They’re ambush predators with a great sense of smell, but they usually avoid human interactions. Prey can’t see them coming because the scales of these snakes blend into their environment.

75. Mona Monkey

Mona monkey eating
  • Scientific Name: Cercopithecus mona
  • Habitat: Rainforests of western Africa
  • Size: 2.3 to 3.4 feet long
  • Diet: Fruits, sprouts, leaves, insects

Mona monkeys are active during the day and spend their time in the trees. They forage quickly by storing food in cheek pouches and then eating it once they’re in a safer location. Their cheek pouches can hold the same amount of food as their stomachs. They live in large groups where one male usually leads 10 to 20 females. Males that aren’t part of a group live alone or spend time with other solo males.

76. Monarch Butterfly

Monarch butterfly on purple flowers
  • Scientific Name: Danaus plexippus
  • Habitat: Prairies, meadows, and grasslands of North America, South America, and Australia
  • Size: 3 to 4 inch wingspan
  • Diet: Nectar

Monarch butterflies feed on nectar from flowers while their larvae only feed on milkweed. The caterpillars eat enough to fuel themselves for migration once they become butterflies. When these butterflies migrate, they travel in large groups for thousands of miles. Some monarchs only live for two to six weeks, so they may never complete a full migration. Early in the migrating season, monarchs have longer and redder wings, but they become duller toward the end of the season.

77. Mongoose Lemur

Mongoose lemur sitting on branch
  • Scientific Name: Eulemur mongoz
  • Habitat: Dry forests of northwestern Madagascar
  • Size: 12 to 18 inches long with 16 to 25 inches of tail
  • Diet: Fruits, leaves, flowers, nectar

Mongoose lemurs are a critically endangered species that only inhabits a small area of Madagascar. They’re used to living in dry areas, so they can survive up to six months with no rainfall. They’re active at varying times during the day and night, but they’re more likely to favor nighttime during hot seasons. These lemurs usually live in family groups, including a monogamous mating pair and their offspring. The females are usually more dominant than the males.

78. Monk Saki

Monk saki perched in tree
  • Scientific Name: Pithecia monachus
  • Habitat: Rainforests of Brazil, Peru, Colombia, and Ecuador
  • Size: 2.5 to 5.5 pounds
  • Diet: Fruits, seeds, nuts, insects

Monk sakis live in family groups high in the trees. Each monkey has unique vocalizations that can be recognized by the other family members. They regularly bond with each other through social grooming. Pairs of monk sakis mate for life. However, these mammals are shy and cautious around unfamiliar creatures. They mostly eat plants, but on rare occasions, they may eat small mammals like bats and birds.

79. Monocled Cobra

Monocled cobra in the grass
  • Scientific Name: Naja kaouthia
  • Habitat: Across southeastern Asia
  • Size: 4.4 to 4.9 feet long
  • Diet: Small mammals, snakes, fish, amphibians

The monocled cobra, also known as the Indian spitting cobra, is common in Asia, but it’s highly dangerous. These snakes have venom that acts faster than the venom of any other snakes, and the venom attacks the nervous system. They’re highly aggressive, and they will hiss, rear up, and spread out their hoods before they strike. These snakes have few predators because of their venom, but they’re sometimes hunted by eagles and larger snakes.

80. Monte Iberia Eleuth

Monte Iberia Eleuth on human hand
  • Scientific Name: Eleutherodactylus iberia
  • Habitat: Rainforests of Cuba
  • Size: 0.37 to 0.4 inches long
  • Diet: Insects, moths, spiders

These are the smallest frogs in the Northern Hemisphere, but if you look closely, they have beautiful yellow stripes. Their vibrant coloring alerts predators that these amphibians are dangerous. If threatened, these frogs may release a poisonous toxin that will paralyze muscles if ingested. They’re one of the few frog species that don’t have a tadpole stage. Instead, they hatch out of eggs as even tinier versions of the adults.

81. Montezuma Quail

Montezuma quail with chick
  • Scientific Name: Cyrtonyx montezumae
  • Habitat: Forests on steep mountains of Mexico and the southwestern United States
  • Size: 8 to 9 inches long
  • Diet: Tubers, bulbs, seeds, insects

When searching for food, Montezuma quails use their long claws to dig up dirt and soil in search of plants and insects. Their claws are about half the length of their feet. If they sense danger while foraging, they may crouch and freeze. Their spotted feathers can help them blend into their surroundings while sitting still. On most days, these quails stay in the same territory of about 50 yards.

82. Moon Jellyfish

Moon jellyfish under blue light
  • Scientific Name: Aurelia aurita
  • Habitat: Temperate oceans
  • Size: 10 to 18 inches wide
  • Diet: Zooplankton, mollusk larvae, crustaceans, small fish

Moon jellyfish can be found across warm water of all oceans, especially near coastal areas. They’re the oldest multi-organ animal today, with evidence of them existing before dinosaurs. Underwater, they appear to glow when a substance inside them called luciferin reacts with oxygen. These creatures sometimes wash up on beaches, but they’re not dangerous because they don’t have enough stinging power to harm human skin.

83. Moose

  • Scientific Name: Alces alces
  • Habitat: Forested areas of northern North America
  • Size: 600 to 1,500 pounds
  • Diet: Leaves, twigs, grass

Moose are the largest members of the deer family and the tallest mammals in North America. Male moose grow antlers when they’re about a year old, but every winter, they shed their antlers and grow new ones. The massive antlers don’t serve any purpose outside of the mating season, which is when they compete with other males. Despite their large size, moose are strong swimmers. They can dive up to 20 feet below the surface and stay underwater for about 30 seconds.

84. Mount Lyell Salamander

Mount Lyell Salamander on stone
  • Scientific Name: Hydromantes platycephalus
  • Habitat: Rocky areas of the Sierra Nevada
  • Size: 1.7 to 3.5 inches long
  • Diet: Insects, insect larvae, spiders

Mount Lyell salamanders are surprisingly tolerant of cold weather, handling temperatures as low as 35 degrees Fahrenheit. When temperatures reach below freezing, the salamanders move to their below-ground habitats and often become inactive. These amphibians have adapted to survive on rocky mountains. They have webbed feet to help them climb, and they used their tails to help them balance.

85. Mountain Bluebird

Mountain bluebird sitting on log
  • Scientific Name: Sialia currucoides
  • Habitat: Plains and mountains of North America
  • Size: 6 to 7 inches long
  • Diet: Insects, spiders, berries, seeds

These birds have the brightest blue feathers of any bluebird species. Some Native Americans believed their feathers were sacred symbols. Mountain bluebirds are currently the official state bird of Nevada and Idaho. They’re capable of breeding with other bluebird species to produce hybrids. They can be aggressive, especially during their mating season. They may dive-bomb or snap at any creatures that get too close to their nests.

86. Mountain Lion

Mountain lion standing on rock
  • Scientific Name: Felis Concolor
  • Habitat: Forests and mountains of North and South America
  • Size: 65 to 220 pounds
  • Diet: Deer, elk, rabbits, turkeys, sheep

Mountain lions, also commonly called cougars or pumas, are large felines, but they’re just as agile as any other cat. They can jump as high as a two-story building and they can run up to 50 miles per hour. They make sounds similar to house cats, including, purring, hissing, and meowing. When they’re born, these felines have blue eyes, but their eyes change to yellow as they mature. They spend most of their time alone, and they will fight any animals that enter their territory.

87. Mountain Tapir

Mountain tapir foraging
  • Scientific Name: Tapirus pinchaque
  • Habitat: Across the Andes Mountains of northwestern South America
  • Size: 300 to 550 pounds
  • Diet: Leaves, twigs, fruit, aquatic plants

Mountain tapirs are the smallest tapir species, and they’re the only ones not native to tropical rainforests. Thus, they often grow thicker fur than other tapirs to help them stay warm at high elevations. They eat a variety of plants, including aquatic vegetation. They can stay underwater for several minutes while foraging because they can use their long noses as snorkels. In general, they rely heavily on their sense of smell because they have poor eyesight.

88. Mourning Dove

Mourning Dove perched on branch
  • Scientific Name: Zenaida macroura
  • Habitat: Open and semi-open habitats of North America
  • Size: 8.9 to 14.2 inches long
  • Diet: Seeds, grains, herbs, fruits

Mourning doves have a distinct call that sounds like “coo-woo-woo-woo,” so it’s sometimes mistaken for an owl. However, these calls are usually only made by males. These birds primarily feed on the ground, and they search for plant materials rather than insects. When they eat, they store the food they’ve collected in their crops, and then they fly to a nearby perch to digest it. They can eat up to 20% of their body weight per day.

89. Mozambique Spitting Cobra

Mozambique spitting cobra on the ground
  • Scientific Name: Naja mossambica
  • Habitat: Forests and savannas of southern Africa
  • Size: 3 to 3.5 feet long
  • Diet: Amphibians, small mammals, birds, other snakes

These reptiles are one of Africa’s most dangerous snakes because they can spit highly dangerous venom into the eyes of other creatures. The venom can shoot four to eight feet and destroy the victim’s tissue. They’re fast snakes that don’t shy away from danger, and they’ve even been known to bite people who are sleeping. Before they attack, these snakes will usually rear up and raise their hoods to get a better angle for spitting venom.

90. Mud Salamander

Bright red mud salamander
  • Scientific Name: Pseudotriton montanus
  • Habitat: Muddy habitats of the eastern United States
  • Size: 6 to 8 inches long
  • Diet: Insects, spiders, worms

The colors of these salamanders change during different life stages. Young salamanders have bright red skin, but it usually turns reddish-brown once they are fully mature. Like most brightly-colored amphibians, these salamanders are mildly poisonous. They can release toxic secretions from their bodies if predators try to eat them.

91. Mugger Crocodile

Mugger crocodile in swampy area
  • Scientific Name: Crocodylus palustris
  • Habitat: Freshwater of India and neighboring countries
  • Size: 90 to 440 pounds
  • Diet: Fish, frogs, snakes, turtles, medium-sized mammals

Mugger crocodiles, also called marsh crocodiles, have flat heads, so their eyes, nose, and ears are on top. Like other crocodiles, this allows them to see and hear above the water while the rest of their bodies are submerged underwater. They have webbed feet designed to help them make sudden movements in the water. The term “mugger” came from an Indian word meaning “water monster.”

92. Mule

Mule looking at camera
  • Scientific Name: Equus mulus
  • Habitat: Domesticated
  • Size: 800 to 1,000 pounds
  • Diet: Grass, weeds, vegetables

Mules are a hybrid species created by breeding a male donkey with a female horse. Breeding a female donkey with a male horse will give you a different species called a hinny. Mules were bred before 3000 BC as a way to combine the best traits of horses and donkeys. They’re known for being stronger and gentler than both species. Like most hybrid animals, mules are almost always infertile.

93. Mule Deer

Mule deer in field
  • Scientific Name: Odocoileus hemionus
  • Habitat: Mountains, forests, and scrublands of western North America
  • Size: 120 to 330 pounds
  • Diet: Flowers, leaves, twigs, fruit

Mule deer are named for their ears, which are large like mule ears. While most deer only have one offspring at a time, mule deer can give birth to two to four babies. These mammals aren’t picky when it comes to food because they’re known for eating over 800 different types of vegetation. They’re also agile creatures that can run up to 45 miles per hour to escape predators. However, they often jump around and keep their legs stiff as they land instead of running.

94. Muscovy Duck

Muscovy duck by water
  • Scientific Name: Cairina moschata
  • Habitat: Wetlands from Texas through South America
  • Size: 6 to 15 pounds
  • Diet: Insects, grass, weeds, slugs, snails

Muscovy ducks are a common domesticated duck species, but some can still be found in the wild in North and South America. These birds are easily distinguished by the red fleshy skin (called a caruncle) on their faces paired with black and white feathers. They have easygoing temperaments and they rarely make noise, which is why they’re so common on farms. They will wag their tails if they feel excited or threatened, similar to dogs. These birds may also hiss to scare away predators.

95. Muskox

Muskox standing in the snow
  • Scientific Name: Ovibos moschatus
  • Habitat: Snowy northern regions of North American and Eurasia
  • Size: 400 to 900 pounds
  • Diet: Grass, sedges, woody plants

The thick coat of the muskox makes them look soft and cuddly, but it’s actually an adaptation to protect them from dangerously low temperatures. They have a double coat of fur, and the bottom layer is dense wool against their skin known as “qiviut.” They also have strong hooves that they use to dig through ice to find plants to eat. These mammals have horizontal pupils to protect their eyes from the sun’s glare when it reflects off ice.

96. Muskrat

Muskrat sitting in wetlands
  • Scientific Name: Ondatra zibethicus
  • Habitat: Wetlands in parts of North America, Europe, and Asia
  • Size: 1.3 to 4.4 pounds
  • Diet: Aquatic vegetation, clams, mussels, snails, crayfish

Muskrats spend a lot of time in the water, and they can stay submerged for up to 20 minutes at a time. They don’t build dams like beavers, but they build houses out of sticks that are big enough to fit their whole families. Muskrat fossils have been traced back as far as four million years. Over time, muskrats grew in body, skull, and teeth size to adapt to their environment.

97. Mute Swan

Mute swan floating on the water
  • Scientific Name: Cygnus olor
  • Habitat: Aquatic habitats of Europe, Asia, Africa, and North America
  • Size: 19 to 26 pounds
  • Diet: Grains, aquatic vegetation

Mute swans are only native to the British Isles, northern Europe, and north central Asia, but they have been introduced to many other areas of the world over the years. They’re considered invasive in new places because of their aggression and destructive behaviors. These birds aren’t mute like their name implies, but instead, they make muffled trumpet sounds when defending their territories.

A Beautiful World Filled with Animals

There are so many incredible animals that start with the letter M. So, imagine how many other animals are under other letters of the alphabet. Don’t be afraid to let your curiosity take over, allowing you to research as many species as possible.