Humpback Whale

The plaintive song of the humpback whale can travel for great distances underwater.

Humpback whales are known for their magical songs, which travel for great distances through the world's oceans. These sequences of moans, howls, cries, and other noises are quite complex and often continue for hours on end. Scientists are studying these sounds to decipher their meaning. It is most likely that humpbacks sing to communicate with others and to attract potential mates.

These whales are found near coastlines, feeding on tiny shrimp-like krill, plankton, and small fish. Humpbacks migrate annually from summer feeding grounds near the poles to warmer winter breeding waters closer to the Equator. Mothers and their young swim close together, often touching one another with their flippers with what appear to be gestures of affection. Females nurse their calves for almost a year, though it takes far longer than that for a humpback whale to reach full adulthood. Calves do not stop growing until they are ten years old.

Humpbacks are powerful swimmers, and they use their massive tail fin, called a fluke, to propel themselves through the water and sometimes completely out of it. These whales, like others, regularly leap from the water, landing with a tremendous splash. Scientists aren't sure if this breaching behavior serves some purpose, such as cleaning pests from the whale's skin, or whether whales simply do it for fun.

Fast Facts

Type:

Mammal

Diet:

Omnivore

Size:

48 to 62.5 ft (14.6 to 19 m)

Weight:

40 tons (36 metric tons)

Group name:

Pod

Protection status:

Endangered

Size relative to a bus:

Jaguar

Jaguars, the largest of South America's big cats, once roamed much of the Americas. Today they are found in only a few remote regions.

Jaguars are the largest of South America's big cats. They once roamed from the southern tip of that continent north to the region surrounding the U.S.-Mexico border. Today significant numbers of jaguars are found only in remote regions of South and Central America—particularly in the Amazon basin.

These beautiful and powerful beasts were prominent in ancient Native American cultures. In some traditions the Jaguar God of the Night was the formidable lord of the underworld. The name jaguar is derived from the Native American word yaguar, which means "he who kills with one leap."

Unlike many other cats, jaguars do not avoid water; in fact, they are quite good swimmers. Rivers provide prey in the form of fish, turtles, or caimans—small, alligatorlike animals. Jaguars also eat larger animals such as deer, peccaries, capybaras, and tapirs. They sometimes climb trees to prepare an ambush, killing their prey with one powerful bite.

Most jaguars are tan or orange with distinctive black spots, dubbed "rosettes" because they are shaped like roses. Some jaguars are so dark they appear to be spotless, though their markings can be seen on closer inspection.

Jaguars live alone and define territories of many square miles by marking with their waste or clawing trees.

Females have litters of one to four cubs, which are blind and helpless at birth. The mother stays with them and defends them fiercely from any animal that may approach—even their own father. Young jaguars learn to hunt by living with their mothers for two years or more.

Jaguars are still hunted for their attractive fur. Ranchers also kill them because the cats sometimes prey upon their livestock.

Fast Facts

Type:

Mammal

Diet:

Carnivore

Average life span in the wild:

12 to 15 years

Size:

Head and body, 5 to 6 ft (1.5 to 1.8 m); tail, 27.5 to 36 in (70 to 91 cm)

Weight:

100 to 250 lbs (45 to 113 kg)

Protection status:

Near Threatened

Size relative to a 6-ft (2-m) man:

Kinkajou

Resembling a small primate but actually related to the raccoon, the Central and South American kinkajou uses its long tongue to remove honey from beehives and nectar from flowers.

Kinkajous live in the tropical forests of Central and South America, where they spend most of their time in the trees. They are able to turn their feet backwards to run easily in either direction along branches or up and down trunks. The kinkajou also has a prehensile (gripping) tail that it uses much like another arm. Kinkajous often hang from this incredible tail, which also aids their balance and serves as a cozy blanket while the animal sleeps high in the canopy.

Though many of its features and traits sound like those of a primate, the kinkajou is actually related to the raccoon.

Kinkajous are sometimes called honey bears because they raid bees' nests. They use their long, skinny tongues to slurp honey from a hive, and also to remove insects like termites from their nests. Kinkajous also eat fruit and small mammals, which they snare with their nimble front paws and sharp claws. They roam and eat at night, and return each morning to sleep in previously used tree holes.

Kinkajous form treetop groups and share social interactions such as reciprocal grooming. They are vocal animals—though seldom seen, they are often heard screeching and barking in the tropical forest canopy.

Female kinkajous give birth to one offspring in spring or summer. The baby is born with its eyes shut and cannot see for a month. It develops quickly, however, and by the end of the second month, it is already able to hang upside down from its tail.

Fast Facts

Type:

Mammal

Diet:

Omnivore

Size:

Head and body, 17 to 22 in (43 to 56 cm); Tail, 16 to 22 in (41 to 56 cm)

Weight:

3 to 7 lbs (1 to 3 kg)

Group name:

Troop

Size relative to a 6-ft (2-m) man:

Quetzal

Sacred to ancient Mesoamerican people, gorgeously plumed quetzals live in the mountains of Central America.

The resplendent quetzal is an aptly named bird that many consider among the world's most beautiful. These vibrantly colored animals live in the mountainous, tropical forests of Central America where they eat fruit, insects, lizards, and other small creatures.

During mating season, male quetzals grow twin tail feathers that form an amazing train up to three feet (one meter) long. Females do not have long trains, but they do share the brilliant blue, green, and red coloring of their mates. Male colors tend to be more vibrant.

Resplendent quetzal pairs use their powerful beaks to hollow hole nests in rotted trees or stumps. Inside, they take turns incubating two or three eggs—though males have such long tails that they sometimes stick outside the nest.

Young quetzals can fly at about three weeks of age, but males do not begin to grow their long tail plumes for three years.

Resplendent quetzals are also known as Guatemalan quetzals, and the birds are the symbol of that nation. Guatemala also trades in currency known as the "quetzal."

Unfortunately, these striking birds are threatened in Guatemala and elsewhere throughout their range. They are sometimes trapped for captivity or killed, but their primary threat is the disappearance of their tropical forest homes. In some areas, most notably Costa Rica's cloud forests, protected lands preserve habitat for the birds and provide opportunities for ecotourists and eager bird watchers from around the globe.

Such admirers continue a long history of adoration for the quetzal. The bird was sacred to the ancient Maya and Aztec peoples, and royalty and priests wore its feathers during ceremonies.

Fast Facts

Type:

Bird

Diet:

Omnivore

Size:

Body, 15 to 16 in (38 to 40.5 cm); tail, 24 in (61 cm)

Weight:

7 to 8 oz (200 to 225 g)

Protection status:

Threatened

Size relative to a 6-ft (2-m) man:

Macaw

Of the 17 species of macaws, several are endangered, including the beautiful hyacinth, seen here in flight.

Macaws are beautiful, brilliantly colored members of the parrot family.

Many macaws have vibrant plumage. The coloring is suited to life in Central and South American rain forests, with their green canopies and colorful fruits and flowers. The birds boast large, powerful beaks that easily crack nuts and seeds, while their dry, scaly tongues have a bone inside them that makes them an effective tool for tapping into fruits.

Macaws also have gripping toes that they use to latch onto branches and to grab, hold, and examine items. The birds sport graceful tails that are typically very long.

Macaws are intelligent, social birds that often gather in flocks of 10 to 30 individuals. Their loud calls, squawks, and screams echo through the forest canopy. Macaws vocalize to communicate within the flock, mark territory, and identify one another. Some species can even mimic human speech.

Flocks sleep in the trees at night, and in the morning they may fly long distances to feed on fruit, nuts, insects, and snails. Some species also eat damp soil, which may help to neutralize chemicals in their fruity diet and ease their stomachs.

Macaws typically mate for life. They not only breed with, but also share food with their mates and enjoy mutual grooming. In breeding season, mothers incubate eggs while fathers hunt and bring food back to the nest.

There are 17 species of macaws, and several are endangered. These playful birds are popular pets, and many are illegally trapped for that trade. The rain forest homes of many species are also disappearing at an alarming rate.

Hyacinth, red-fronted, and blue-throated macaws are seriously endangered. The glaucus macaw and Spix's macaw may already be extinct in the wild.

Fast Facts

Type:

Bird

Diet:

Omnivore

Average life span in the wild:

Up to 60 years

Size:

11.8 to 39.5 in (30 to 100 cm)

Weight:

4.5 oz to 3.75 lbs (129 to 1,695 g)

Group name:

Flock

Did you know?

The hyacinth macaw—the largest of all parrots—has an enormous wingspan of more than 4 ft (127 cm).

Size relative to a 6-ft (2-m) man:

Bobcat

Bobcats, named for their "bobbed" tails, have ears that resemble their feline cousin, the lynx.

Bobcats are elusive and nocturnal, so they are rarely spotted by humans. Although they are seldom seen, they roam throughout much of North America and adapt well to such diverse habitats as forests, swamps, deserts, and even suburban areas.

Bobcats, sometimes called wildcats, are roughly twice as big as the average housecat. They have long legs, large paws, and tufted ears similar to those of their larger relative, the Canada lynx. Most bobcats are brown or brownish red with a white underbelly and short, black-tipped tail. The cat is named for its tail, which appears to be cut or "bobbed."

Fierce hunters, bobcats can kill prey much bigger than themselves, but usually eat rabbits, birds, mice, squirrels, and other smaller game. The bobcat hunts by stealth, but delivers a deathblow with a leaping pounce that can cover 10 feet (3 meters).

Bobcats are solitary animals. Females choose a secluded den to raise a litter of one to six young kittens, which will remain with their mother for 9 to 12 months. During this time they will learn to hunt before setting out on their own.

In some areas, bobcats are still trapped for their soft, spotted fur. North American populations are believed to be quite large, with perhaps as many as one million cats in the United States alone.

Fast Facts

Type:

Mammal

Diet:

Carnivore

Average life span in the wild:

10 to 12 years

Size:

Head and body, 26 to 41 in (66 to 104 cm); tail, 4 to 7 in (10 to 18 cm)

Weight:

11 to 30 lbs (5 to 14 kg)

Did you know?

The bobcat is the most abundant wildcat in the U.S. and has the greatest range of all native North American cats.

Size relative to a 6-ft (2-m) man:

Mountain Lion

Mountain lions do not like to share their territory and are constantly on the lookout for invaders.

This powerful predator roams the Americas, where it is also known as a puma, cougar, and catamount. This big cat of many names is also found in many habitats, from Florida swamps to Canadian forests.

Mountain lions like to prey on deer, though they also eat smaller animals such as coyotes, porcupines, and raccoons. They usually hunt at night or during the gloaming hours of dawn and dusk. These cats employ a blend of stealth and power, stalking their prey until an opportunity arrives to pounce, then going for the back of the neck with a fatal bite. They will hide large carcasses and feed on them for several days.

Mountain lions once roamed nearly all of the United States. They were prized by hunters and despised by farmers and ranchers who suffered livestock losses at their hands. Subsequently, by the dawn of the 20th century, mountain lions were eliminated from nearly all of their range in the Midwest and Eastern U.S.—though the endangered Florida panther survives.

Today, whitetail deer populations have rebounded over much of the mountain lion's former range and a few animals have appeared in more eastern states such as Missouri and Arkansas. Some biologists believe that these big cats could eventually recolonize much of their Midwest and Eastern range—if humans allow them to do so. In most western U.S. states and Canadian provinces, populations are considered sustainable enough to allow managed sport hunting.

Mountain lions require a lot of room—only a few cats can survive in a 30-square-mile (78-square-kilometer) range. They are solitary and shy animals, seldom seen by humans. While they do occasionally attack people—usually children or solitary adults—statistics show that, on average, there are only four attacks and one human fatality each year in all of the U.S. and Canada.

Fast Facts

Type:

Mammal

Diet:

Carnivore

Size:

Head and body, 3.25 to 5.25 ft (1 to 1.6 m); Tail, 23.5 to 33.5 in (60 to 85 cm)

Weight:

136 lbs (62 kg)

Protection status:

Endangered

Size relative to a 6-ft (2-m) man:

Lynx

The lynx is known for the black tufts of fur on the tips of its ears, which function as hearing aids.

The lynx is a solitary cat that haunts the remote northern forests of North America, Europe, and Asia. Lynx are covered with beautiful thick fur that keeps them warm during frigid winters. Their large paws are also furry and hit the ground with a spreading toe motion that makes them function as natural snowshoes.

These stealthy cats avoid humans and hunt at night, so they are rarely seen.

There are several species of lynx. Few survive in Europe but those that do, like their Asian relatives, are typically larger than their North American counterpart, the Canada lynx.

All lynx are skilled hunters that make use of great hearing (the tufts on their ears are a hearing aid) and eyesight so strong that a lynx can spot a mouse 250 feet (75 meters) away.

Canada lynx eat mice, squirrels, and birds, but prefer the snowshoe hare. The lynx are so dependent on this prey that their populations fluctuate with a periodic plunge in snowshoe hare numbers that occurs about every ten years. Bigger Eurasian lynx hunt deer and other larger prey in addition to small animals.

Lynx mate in early spring or late winter. About two months later, females give birth to a litter of one to four young.

Humans sometimes hunt lynx for their beautiful fur. One endangered population, the Iberian lynx, struggles to survive in the mountains of Spain, far from the cold northern forests where most lynx live.

Fast Facts

Type:

Mammal

Diet:

Carnivore

Size:

Head and body, 32 to 40 in (80 to 100 cm); Tail, 4 to 8 in (10 to 20 cm)

Weight:

22 to 44 lbs (10 to 20 kg)

Protection status:

Threatened

Size relative to a 6-ft (2-m) man:

Loggerhead Sea Turtle

An endangered loggerhead turtle swims gracefully along the sea floor.

Loggerhead turtles are the most abundant of all the marine turtle species in U.S. waters. But persistent population declines due to pollution, shrimp trawling, and development in their nesting areas, among other factors, have kept this wide-ranging seagoer on the threatened species list since 1978.

Their enormous range encompasses all but the most frigid waters of the world's oceans. They seem to prefer coastal habitats, but often frequent inland water bodies and will travel hundreds of miles out to sea.

The largest of all hard-shelled turtles—leatherbacks are bigger but have soft shells—loggerheads have massive heads, strong jaws, and a reddish-brown shell, or carapace. Adult males reach about three feet (nearly one meter) in shell length and weigh about 250 pounds (113 kilograms), but large specimens of more than 1,000 pounds (454 kilograms) have been found.

They are primarily carnivores, munching jellyfish, conchs, crabs, and even fish, but will eat seaweed and sargassum occasionally.

Mature females will often return, sometimes over thousands of miles, to the beach where they hatched to lay their eggs. Worldwide population numbers are unknown, but scientists studying nesting populations are seeing marked decreases despite endangered species protections.

Fast Facts

Type:

Reptile

Diet:

Carnivore

Average life span in the wild:

More than 50 years

Size:

36 in (90 cm)

Weight:

253 lbs (115 kg)

Group name:

Flotilla

Protection status:

Endangered

Did you know?

Sea turtles can move through the water at speeds of up to 15 mi (24 km) per hour.

Size relative to a 6-ft (2-m) man:

Olive Ridley Sea Turtle

Olive ridleys get their name from the coloring of their heart-shaped shell, which starts out gray but becomes olive green once the turtles are adults. They have one to two visible claws on each of their paddle-like flippers.

The olive ridley turtle is named for the generally greenish color of its skin and shell, or carapace. It is closely related to the Kemp’s ridley, with the primary distinction being that olive ridleys are found only in warmer waters, including the southern Atlantic, Pacific and Indian Oceans.

Olive and Kemp’s ridleys are the smallest of the sea turtles, weighing up to 100 pounds (45 kilograms) and reaching only about 2 feet (65 centimeters) in shell length. The olive ridley has a slightly smaller head and smaller shell than the Kemp’s.

These turtles are solitary, preferring the open ocean. They migrate hundreds or even thousands of miles every year, and come together as a group only once a year for the arribada, when females return to the beaches where they hatched and lumber onshore, sometimes in the thousands, to nest.

Olive ridleys have nesting sites all over the world, on tropical and subtropical beaches. During nesting, they use the wind and the tide to help them reach the beach. Females lay about a hundred eggs, but may nest up to three times a year. The nesting season is from June to December.

The olive ridley is mostly carnivorous, feeding on such creatures as jellyfish, snails, crabs, and shrimp. They will occasionally eat algae and seaweed as well. Hatchlings, most of which perish before reaching the ocean, are preyed on by crabs, raccoons, pigs, snakes, and birds, among others. Adults are often taken by sharks.

Though the olive ridley is widely considered the most abundant of the marine turtles, by all estimates, it is in trouble. Rough estimates put the worldwide population of nesting females at about 800,000, but its numbers, particularly in the western Atlantic, have declined precipitously. The United States lists the western Atlantic population of olive ridleys as endangered and all other populations as threatened.

Many governments have protections for olive ridleys, but still, eggs are taken and nesting females are slaughtered for their meat and skin. Fishing nets also take a large toll, frequently snagging and drowning these turtles.

Fast Facts

Type:

Reptile

Diet:

Omnivore

Average life span in the wild:

50 years

Size:

2 to 2.5 ft (62 to 70 cm)

Weight:

Up to 100 lbs (45 kg)

Protection status:

Endangered

Did you know?

Male olive ridleys can be distinguished from females by their tails, which stick out beyond their carapace.

Size relative to a 6-ft (2-m) man:

Wood Stork

Wood storks fish with an unusual but effective method: Opening their bills underwater, they wait for a fish to pass by, then snap!, like a mousetrap, the bill is closed, and the fish is eaten.

Wood storks are tall, white denizens of freshwater or brackish wetlands and swamps. They can be identified by their long legs, featherless heads, and prominent bills.

These waders feed on minnows in shallow water by using their bills to perform a rare and effective fishing technique. The stork opens its bill and sticks it into the water, then waits for the touch of an unfortunate fish that wanders too close. When it feels a fish, the stork can snap its bill shut in as little as 25 milliseconds—an incredibly quick reaction time matched by few other vertebrates.

The storks prefer to employ this technique in isolated pools created by tides or falling freshwater levels, where fish congregate en masse. In some areas, such as Florida, breeding begins with the dry season that produces these optimal fishing conditions.

Though wood storks eat small fish, they eat a lot of them. An average nesting pair, with two fledglings, may eat over 400 pounds (181 kilograms) of fish during a single breeding season.

Wood storks are social animals. They feed in flocks and nest in large rookeries—sometimes several pairs to a single tree. Females lay two to five eggs, which both sexes incubate for about one month. Young fledge about two months after hatching.

Wood storks breed in the southeastern United States and are the only stork to breed in the U.S. They also breed in Central and South America from Mexico to Argentina. Though U.S. populations are endangered—probably because of the loss of optimal feeding habitat—the South American stork populations are in better shape.

Fast Facts

Type:

Bird

Diet:

Carnivore

Average life span in the wild:

11 to 18 years

Size:

Body, 33 to 45 in (85 to 115 cm); wingspan, 4.9 to 5.8 ft (1.5 to 1.8 m)

Weight:

4.5 to 5.8 lbs (2.1 to 2.6 kg)

Group name:

Colony or flock

Size relative to a 6-ft (2-m) man:

Sandhill Crane

Most sandhill cranes live in freshwater wetlands, feeding on plants, grains, mice, snakes, insects, and worms.

Sandhills are the most common of all the world's cranes. A fossil from the Miocene Epoch, some ten million years ago, was found to be structurally the same as the modern sandhill crane. Today, these large birds are found predominately in North America. They range south to Mexico and Cuba, and as far west as Siberia.

Migratory subspecies of sandhill cranes breed in the Northern U.S., Canada, Alaska, and Siberia. Each winter they undertake long southern journeys to wintering grounds in Florida, Texas, Utah, Mexico, and California. En route, more than three-fourths of all sandhill cranes use migratory staging areas in a single 75-mile (120-kilometer) stretch along Nebraska's Platte River.

Most sandhill cranes live in freshwater wetlands. They are opportunistic eaters that enjoy plants, grains, mice, snakes, insects, or worms. They often dig in the soil for tubers and can sometimes cause significant crop damage, which brings them into conflict with farmers.

The birds are naturally gray and their heads are topped with a crimson crown. Some cranes preen themselves by adding mud to their feathers and thus taking on a temporary brown hue. This may happen because the birds use their bills to probe for food in muddy wetland soil.

During mating, pairs vocalize in a behavior known as "unison calling." They throw their heads back and unleash a passionate duet—an extended litany of coordinated song. Cranes also dance, run, leap high in the air and otherwise cavort around—not only during mating but all year long.

Sandhill cranes usually nest in wetlands and create a structure from whatever plants may be at hand. Females typically lay two eggs, which both parents incubate. Males take responsibility for defending the nest.

Fast Facts

Type:

Bird

Diet:

Omnivore

Average life span in the wild:

20 years

Size:

Body, 31.5 to 47.2 in (80 to 120 cm); wingspan, 5 to 6 ft (1.2 to 1.3 m)

Weight:

6.5 to 14 lbs (3 to 6.5 kg)

Size relative to a 6-ft (2-m) man:

Ostrich

Portrait of an ostrich.

The flightless ostrich is the world's largest bird. They roam African savanna and desert lands and get most of their water from the plants they eat.

Though they cannot fly, ostriches are fleet, strong runners. They can sprint up to 43 miles (70 kilometers) an hour and run over distance at 31 miles (50 kilometers) an hour. They may use their wings as "rudders" to help them change direction while running. An ostrich's powerful, long legs can cover 10 to 16 feet (3 to 5 meters) in a single stride. These legs can also be formidable weapons. Ostrich kicks can kill a human or a potential predator like a lion. Each two-toed foot has a long, sharp claw.

Ostriches live in small herds that typically contain less than a dozen birds. Alpha males maintain these herds, and mate with the group's dominant hen. The male sometimes mates with others in the group, and wandering males may also mate with lesser hens. All of the group's hens place their eggs in the dominant hen's nest—though her own are given the prominent center place. The dominant hen and male take turns incubating the giant eggs, each one of which weighs as much as two dozen chicken eggs.

Contrary to popular belief, ostriches do not bury their heads in the sand. The old saw probably originates with one of the bird's defensive behaviors. At the approach of trouble, ostriches will lie low and press their long necks to the ground in an attempt to become less visible. Their plumage blends well with sandy soil and, from a distance, gives the appearance that they have buried their heads in the sand.

Ostriches typically eat plants, roots, and seeds but will also eat insects, lizards, or other creatures available in their sometimes harsh habitat.

Fast Facts

Type:

Bird

Diet:

Omnivore

Average life span in the wild:

30 to 40 years

Size:

7 to 9 ft (2.1 to 2.7 m)

Weight:

220 to 350 lbs (100 to 160 kg)

Group name:

Herd

Did you know?

The ostrich has the largest eye of any land animal. Its eye measures almost 2 in (5 cm) across.

Size relative to a 6-ft (2-m) man:

Green Basilisk Lizard

Green basilisk lizards can avoid danger by darting across water. They have specially designed feet and a unique running style that keeps them from sinking.

The green basilisk lizard is also called a plumed or double-crested basilisk; but its amazing ability to run on water gives this species its most recognizable moniker: the Jesus Christ lizard.

Abundant in the tropical rain forests of Central America, from southern Mexico to Panama, green basilisks spend much of their time in the trees and are never far from a body of water. When threatened, they can drop from a tree into the water and sprint, upright, about 5 feet (1.5 meters) per second across the surface.

To accomplish this, they have long toes on their rear feet with fringes of skin that unfurl in the water, increasing surface area. As they rapidly churn their legs, they slap their splayed feet hard against the water, creating a tiny air pocket that keeps them from sinking, provided they maintain their speed. They can move along the surface like this for 15 feet (4.5 meters) or more. When gravity eventually does take over, the basilisk resorts to its excellent swimming skills to continue its flight.

Part of the iguana family, green basilisks grow to about 2 feet (61 centimeters) in length, including their long, whip-like tail. Males have distinctive, high crests on their heads and backs, which they use to impress females.

Pregnant females prepare a shallow trench where they lay up to 20 eggs. The mother then leaves the eggs to hatch on their own. Hatchlings are born with the ability to run (on land and water), climb, and swim.

Green basilisks are omnivores, surviving on a diet of plant material, insects, fruit, and small vertebrates. They are common throughout their range and have no special status, but abundant natural predators like snakes and birds keep these amazing lizards on their toes.

Fast Facts

Type:

Reptile

Diet:

Omnivore

Average life span in captivity:

Up to 10 years

Size:

2 to 2.5 ft (61 to 76 cm) including the tail

Weight:

Up to 7 oz (200 g)

Did you know?

Basilisk lizards are excellent swimmers and are capable of remaining underwater for up to 30 minutes.

Size relative to a 6-ft (2-m) man:

Web-Footed Gecko

The web-footed gecko's salmon-colored skin and light-brown stripes help it stay camouflaged in the Namib Desert's reddish sands.

The ghostly web-footed gecko is nearly translucent with a pale, salmon-colored undertone and light-brown stripes. Their color provides perfect camouflage among the powdery reddish sands of the Namib Desert, their primary habitat.

These geckos have adapted their webbed feet not only to help them stay atop, but to bury beneath the dunes of the Namib Desert. Strictly nocturnal lizards, they spend the day in self-dug burrows and emerge at night to feed.

Their bloodshot-looking eyes are massively oversized to help them detect prey, which includes crickets, grasshoppers, and small spiders. They move surprisingly quickly across the sand, and adhesive pads on their toes make them excellent climbers.

Web-foots are considered medium-size geckos, reaching an average size of about four inches (ten centimeters) in length. Males are slightly smaller than females.

People sometimes hunt these tiny lizards for food, and human encroachment is destroying some of its habitat. Their estimated lifespan in the wild is about five years.

Fast Facts

Type:

Reptile

Diet:

Carnivore

Average life span in the wild:

5 years

Size:

4 to 6 in (10 to 15 cm)

Did you know?

Web-footed geckos communicate with a wide range of vocalizations, including squeaks, clicks, and even croaks.

Size relative to a tea cup:

Llama

A llama looks out over the ancient ruins of Machu Picchu, Peru.

The llama is a South American relative of the camel, though the llama does not have a hump. These sturdy creatures are domestic animals used by the peoples of the Andes Mountains. (Their wild relatives are guanacos and vicuñas). Native peoples have used llamas as pack animals for centuries. Typically, they are saddled with loads of 50 to 75 pounds (23 to 34 kilograms). Under such weight they can cover up to 20 miles (32 kilometers) in a single day. Pack trains of llamas, which can include several hundred animals, move large amounts of goods over even the very rough terrain of the Andes.

Llamas are willing pack animals but only to a point. An overloaded llama will simply refuse to move. These animals often lie down on the ground and they may spit, hiss, or even kick at their owners until their burden is lessened.

Llamas graze on grass and, like cows, regurgitate their food and chew it as cud. They chomp on such wads for some time before swallowing them for complete digestion. Llamas can survive by eating many different kinds of plants, and they need little water. These attributes make them durable and dependable even in sparse mountainous terrain.

Llamas contribute much more than transportation to the human communities in which they live. Leather is made from their hides, and their wool is crafted into ropes, rugs, and fabrics. Llama excrement is dried and burned for fuel. Even in death, llamas can serve their human owners—some people slaughter them and eat their meat.

Fast Facts

Type:

Mammal

Diet:

Herbivore

Size:

Height at the shoulder, 47 in (120 cm)

Weight:

250 lbs (113 kg)

Size relative to a 6-ft (2-m) man:

Wolf

Gray wolves once populated large portions of North America, Europe, and Asia, but were hunted to near extinction. Their numbers have rebounded due to conservation and reintroduction efforts.

Wolves are legendary because of their spine-tingling howl, which they use to communicate. A lone wolf howls to attract the attention of his pack, while communal howls may send territorial messages from one pack to another. Some howls are confrontational. Much like barking domestic dogs, wolves may simply begin howling because a nearby wolf has already begun.

Wolves are the largest members of the dog family. Adaptable gray wolves are by far the most common and were once found all over the Northern Hemisphere. But wolves and humans have a long adversarial history. Though they almost never attack humans, wolves are considered one of the animal world's most fearsome natural villains. They do attack domestic animals, and countless wolves have been shot, trapped, and poisoned because of this tendency.

In the lower 48 states, gray wolves were hunted to near extinction, though some populations survived and others have since been reintroduced. Few gray wolves survive in Europe, though many live in Alaska, Canada, and Asia.

Red wolves live in the southeastern United States, where they are endangered. These animals actually became extinct in the wild in 1980. Scientists established a breeding program with a small number of captive red wolves and have reintroduced the animal to North Carolina. Today, perhaps 100 red wolves survive in the wild.

The maned wolf, a distant relative of the more familiar gray and red wolves, lives in South America. Physically, this animal resembles a large, red fox more than its wolf relatives.

Wolves live and hunt in packs of around six to ten animals. They are known to roam large distances, perhaps 12 miles (20 kilometers) in a single day. These social animals cooperate on their preferred prey—large animals such as deer, elk, and moose. When they are successful, wolves do not eat in moderation. A single animal can consume 20 pounds (9 kilograms) of meat at a sitting. Wolves also eat smaller mammals, birds, fish, lizards, snakes, and fruit.

Wolfpacks are established according to a strict hierarchy, with a dominant male at the top and his mate not far behind. Usually this male and female are the only animals of the pack to breed. All of a pack's adults help to care for young pups by bringing them food and watching them while others hunt.

Fast Facts

Type:

Mammal

Diet:

Carnivore

Average life span in the wild:

6 to 8 years

Size:

Head and body, 36 to 63 in (91 to 160 cm); Tail, 13 to 20 in (33 to 51 cm)

Weight:

40 to 175 lbs (18 to 79 kg)

Group name:

Pack

Protection status:

Endangered

Size relative to a 6-ft (2-m) man: