North America is a continent of varied landscapes, stretching from the Arctic wastes of the far north to the narrow land bridge of Central America in the south and bounded by the Pacific Ocean to the west and the Atlantic Ocean to the east. Just like its habitats, the wildlife of North America is extremely diverse, ranging from hummingbirds to beavers to brown bears and all kinds of biological magnificence in between.
The American BeaverJeff R Clow / Getty Images
The American beaver is one of only two living species of beaver, the other being the Eurasian beaver. It's the world's second-largest rodent (after the capybara of South America) and can attain weights of up to 50 or 60 pounds (23-27 kg). American beavers are stocky animals, with compact trunks and short legs; webbed feet; and broad, flat tails covered with scales. American beavers are constantly building dams-aggregations of sticks, leaves, mud, and twigs that provide these oversized rodents with deep-water habitats in which to hide from predators. Dams also provide winter shelter for other species and create wetlands. Beavers are a keystone species to an ecosystem, with their presence greatly affecting the landscape and food web wherever they reside.
The Brown BearFreder / Getty Images
The brown bear is one of the largest and most powerful terrestrial carnivores of North America. This ursine has non-retractable claws that it uses primarily for digging, and it can run at a considerable clip despite its half-ton (454 kg) size-some individuals have been known to attain speeds of up to 35 mph (56 kph) in pursuit of prey. Befitting their name, brown bears possess a coat of black, brown, or tan fur with longer outer hair, often of a different color; they're also equipped with sizable muscles in their shoulders that give them the strength necessary to dig.
The American AlligatorMoelyn Photos / Getty Images
Not quite as dangerous as its reputation but still populous enough in the southeastern United States to make residents anxious (especially pond and pool owners), the American alligator is a true North American institution. Some adult alligators can attain lengths of more than 13 feet (4 m) and weights of half a ton (454 kg), but most are more modestly sized. It's never a good idea to feed an American alligator, which habituates it to human contact and makes fatal attacks more likely.
The American MooseScott Suriano / Getty Images
The largest member of the deer family, the American moose has a large, heavy body and long legs as well as a long head, a flexible upper lip and nose, large ears, and a prominent dewlap that hangs from its throat. The fur of the American moose is dark brown (almost black) and fades during the winter months. Males grow large antlers-the largest known of any extant mammal-in the spring and shed them in the winter. Their supposed habit of befriending flying squirrels, a la "The Adventures of Rocky and Bullwinkle," has yet to be observed in the wild.
The Monarch ButterflyKerri Wile / Getty Images
The monarch butterfly, also a keystone species, has a black body with white spots and bright orange wings with black borders and veins (some black areas are dappled with white spots too). Monarchs are poisonous to eat due to the toxins in milkweed-which monarch caterpillars ingest before they begin their metamorphosis-and their bright coloration serves as a warning to potential predators. The monarch butterfly is best known for its stunning annual migrations, from southern Canada and the northern United States all the way down to Mexico.
The Nine-Banded ArmadilloDanita Delimont / Getty Images
The world's most widespread armadillo, the nine-banded armadillo, ranges across the expanse of North, Central, and South America. Measuring 14 to 22 inches (36-56 cm) from head to tail and weighing 5 to 15 pounds (2-7 kg), the nine-banded armadillo is a solitary, nocturnal-which explains why it so frequently features as roadkill on North American highways-insectivore. When startled, the nine-banded armadillo can execute a 5-foot (1.5 m) vertical leap, thanks to the tension and flexibility of the armored scutes along its back.
The Tufted TitmouseH .H. Fox Photography / Getty Images
The amusingly named tufted titmouse is a small songbird, easily recognizable by the crest of gray feathers atop its head as well as its big, black eyes; black forehead; and rust-colored flanks. Tufted titmice are notorious for their fashion sense: If possible, they will incorporate discarded rattlesnake scales into their nests and have even been known to pluck the fur off live dogs. Unusually, too, tufted titmouse hatchlings sometimes choose to linger in their nest for an entire year, helping their parents to raise the next year's titmouse flock.
The Arctic WolfEnn Li Photography / Getty Images
The Arctic wolf is a North American subspecies of the gray wolf, the world's largest canid. Adult male Arctic wolves measure between 25 and 31 inches (64 cm-79 cm) tall at the shoulder and can attain weights of up to 175 pounds (79 kg); females tend to be smaller and lighter. Arctic wolves usually live in groups of seven to 10 individuals but will occasionally aggregate in packs of up to 30 members. Despite what you may have seen on TV, Canis lupus arctos is friendlier than most wolves and only rarely attacks humans.
The Gila MonsterJared Hobbs / Getty Images
The only venomous lizard (as opposed to a snake) indigenous to the United States, the gila monster doesn't deserve either its name or its reputation. This "monster" weighs in at only a couple of pounds soaking wet, and it's so sluggish and sleepy that you'd have to be especially crepuscular yourself to get bitten by it. Even if you would get nipped, there's no need to update your will: There hasn't been a confirmed human fatality from a gila monster bite since 1939, which, unfortunately, hasn't prevented many people from reacting disproportionately and deliberately killing any gila monsters they encounter.
The CaribouPatrick Endres / Design Pics / Getty Images
Essentially a North American species of the reindeer, the caribou consists of four variants, ranging from the small (200 pounds for males, or 91 kg) Peary caribou to the much bigger (400-pound males, or 181 kg) boreal woodland caribou. Male caribou are known for their extravagant antlers, with which they battle other males for the right to mate with females during breeding season. Human inhabitants of North America have been hunting Caribou for well over 10,000 years; populations are rebounding somewhat today after being on the decline for a decade, even as this even-toed ungulate is restricted to increasingly narrow slices of territory. Climate change and oil and gas drilling could affect their numbers in the future. Woodland caribou are considered a keystone species in their environment.
The Ruby-Throated Hummingbirdcglade / Getty Images
Ruby-throated hummingbirds weigh less than .14 ounces (4 grams). Both sexes have metallic green feathers along their back and white feathers on their belly; males also have iridescent, ruby-colored feathers on their throats. Ruby-throated hummingbirds beat their wings at an astonishing speed of more than 50 beats per second, enabling these birds to hover and even fly backward when necessary, all while producing a characteristic humming noise that makes this tiny, gentle nectar-eater sound like a giant mosquito.
The Black-Footed FerretWendy Shattil and Bob Rozinski / Getty Images
All the other North American animals on this list are relatively healthy and thriving, but the black-footed ferret hovers on the brink of extinction. In fact, the species was declared extinct in the wild in 1987, with the last 18 of them becoming breeders for their reintroduction into Arizona, Wyoming, and South Dakota. Today, there are 300-400 black-footed ferrets in the West today, which is good news for conservationists but bad news for this mammal's favorite prey, the prairie dog. The goal is 3,000 in the wild, but disease occasionally wipes out populations.