1. Education
Send to a Friend via Email

Animals / Wildlife: Most Popular Articles

These articles are the most popular over the last month.
The Big 6: The Basic Animal Groups
An introduction to the six basic groups of animals including amphibians, birds, fishes, invertebrates, mammals, and reptiles.
The 10 Largest Living Mammals
A list of the largest species in each group of mammals that inhabit our planet today.
Animal Profiles: An A to Z List By Scientific...
An A to Z list of animal profiles available in The Animal Encyclopedia, sorted alphabetically by scientific name.
Animal Profiles: An A to Z List By Common Name
An A to Z list of animal profiles available in The Animal Encyclopedia, sorted alphabetically by common name.
Give A Hoot: Learn 10 Fantastic Facts About Owls
Facts about owls, a group of birds known for their distinct calls, nocturnal habits, and silent flight.
Top 10 Wildlife Conservation Organizations
A list of my top ten favorite conservation organizations that work to protect animals and wildlife around the world.
Mammal Profiles - An A to Z List of Mammals
The following is an A to Z list of mammal profiles available, sorted alphabetically.
10 Simple Things You Can Do to Protect Animals
A list of simple things you can do to help protect animals and wildlife.
What's the Difference Between Prokaryote and...
All living organisms can be sorted into one of two groups depending on the fundamental structure of their cells. These two groups are the prokaryotes and the eukaryotes.
What Defines an Endangered Species?
Definition of endangered species, a term used to refer to a species in danger of extinction throughout all or a significant portion of its range.
10 Cool North American Animals
A list of some of the animals that inhabit North America including the nine-banded armadillo, tufted titmouse, caribou, monarch butterfly, and more.
10 Curious Creatures from the Amazon River Basin
A list of ten animals of the Amazon River basin in South America including harpy eagles, three-toed sloths, toucans, and more.
Beyond the Arms: 11 Facts about Octopi:
From clouds of ink to chromatophores, there's more to octopi than eight arms.
Turtle Tidbits: What Do Turtles Eat?
Turtle eating habits are varied--what they eat depends on the available food sources, the habitat in which the turtle lives and the turtle's behavior.
What Makes an Animal an Animal?
Learn about the key characteristics of animals including multicellularity, eukaryotic cells, sexual reproduction, movement, and more.
The 8 Key Characteristics of Mammals
Learn about the key characteristics of mammals including mammary glands, hair, endothermy, diphyodonty, and more.
Lion Pictures
Lions are the largest of all African cats. They are the second largest cat species worldwide, smaller than only the tiger. Lions range in color from nearly white to tawny yellow, ash brown, ochre, and deep orange-brown. They have a tuft of dark fur at the tip of their tail.
Lions, Tigers, Leopards, Cheetahs and Other Cats
In this photographic guide, find out more about cats, their classification, adaptations, and natural history.
Cool Facts About Bears
Facts about bears, a group of carnivores known for their burly build, impressive agility and, in some species, their winter sleep habits.
Facts You Should Know About Birds
Facts about birds, a group of vertebrates that includes nearly 10,000 species that are unique for their feathers and furculas, also know as wishbones.
Arthropods: Centipedes, Millipedes, Spiders,...
Profile of arthropods, a group of invertebrates that includes insects, spiders, crustaceans, scorpions, centipedes, and many others.
Basic Mammal Groups - Guide to Animal...
An introduction to the basic mammal groups including aardvarks, bats, carnivores, cetaceans, elephants, marsupials, primates, rodents, and many others.
What Is Evolution? The Fossil Record, Natural...
A brief overview of the history of life from the time the first life evolved until the present day. Page 2.
10 Little-Known Facts About Giraffes
Facts about giraffes, a group of mammals that are best known for their tall profile, long neck, and the distinct patchwork pattern of their fur.
What You Should Know About Molluscs
Profile of molluscs, a group of invertebrates that includes squid, octopuses, cuttlefish, nudibranchs, snails, slugs, limpets, mussels, and many more.
Why Mammals Are Amazing
Profile of mammal, a group of four-legged vertebrates that have hair, a four chambered heart and mammary glands.
7 Kinds of Animals Found at the Great Barrier...
A list of some of the animals that inhabit the Great Barrier Reef including sea birds, mollusks, marine mammals, marine reptiles, and more.
What You Probably Don’t Know About Dolphins
Learn interesting facts about dolphins and find out about the characteristics make them different from other animal groups, their life cycle and their evolutionary history.
How a Pride of Lions Operates
Definition of lion pride, a term that refers to a group of line that typically includes about five females and two males and their young.
Top 10 Cute Birds
Of all animals, birds are among the most varied in color, shape and size. In this gallery we'll catch a glimpse of a small handful of the many birds that can claim to be the cutest of their kind.
10 Facts About Jellyfish
Learn interesting facts about jellyfish and find out about the characteristics make them different from other cnidarian groups, their life cycle and their evolutionary history.
Do You Know What an Echinoderm Is?
Profile of echinoderms, a diverse group of marine invertebrates comprising approximately 6000 species.
What Life Is Like for a Jellyfish
The most recognized image of a jellyfish is that of the adult jellyfish, with its bell-shaped body and long tentacles.
How Many Animal Species Are There on Earth?
An article examining how scientists estimate and count the number of animals that live on our planet today.
The Basic Invertebrate Groups
An introduction to six basic groups of invertebrates including arthropods, cnidarians, echinoderms, mollusks, segmented worms, and sponges.
Fast Facts About Mammals
Learn interesting facts about mammals and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Fact Sheet: Carnivores - Racoons, Fur Seals,...
Profile of carnivores, a group of mammals that includes dogs and their relatives, bears, racoons, mustelids, civits, hyenas, aardwolf, and cats.
Learn About the Stages in a Frog's Life
The life cycle of a frog consists of three stages: egg, larva, and adult. As the frog grows it moves through these stages in a process known as metamorphosis. Page 4.
What's a Cnidarian?
Cnidarians are diverse and come in many shapes and sizes but there are some basic features of their anatomy that most members of the group share in common.
Why Habitat Destruction Is So Harmful
Definition of habitat destruction, a term that is used to describe the process by which natural habitat is damaged or destroyed.
Reptile Characteristics
What is a reptile? To answer this question, we must understand the characteristics of reptiles - such as amniotic eggs, scales and ectothermy.
Can You Define “Species”?
The term species can be defined as a group of individual organisms that are capable of interbreeding to produce fertile offspring in nature.
What You Probably Don’t Know About Reptiles
Learn interesting facts about reptiles and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Vertebrates Versus Invertebrates
One criteria by which all animals are described is whether or not they have a backbone. This article explores facts about vertebrates and invertebrates.
Endangered Animals
Endangered animals are species or populations that are at risk of becoming extinct.
Why Insects Are Fascinating
Profile of insects, a highly successful group of animals that accounts for more species of animals than any other class of animals.
Fast Facts About Invertebrates
Learn interesting facts about invertebrates and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Great Facts About Great Horned Owls
Learn interesting facts about great horned owls and find out about the characteristics make them different from other animal groups, their life cycle and their evolutionary history.
Fast Facts About Amphibians
Learn facts about frogs and find out about their diversity, evolutionary history and the characteristics make them different from other vertebrates.
Learn Your Basic Amphibian Groups
An introduction to the three basic groups of amphibians including salamanders and newts, caecilians, and frogs and toads.
Why Keystone Species Are So Important
A keystone species is a species that plays a critical role in maintaining the structure of an ecological community and whose impact on the community is greater than would be expected based on its relative abundance or total biomass.
Reptiles - Reptilia - The Animal Encyclopedia
Profile of reptiles, a group of vertebrates that colonized terrestrial habitats more extensively than their amphibian ancestors.
What’s a Chordate? You’re a Chordate
Profile of chordate, a group of animals that includes vertebrates, tunicates, lancelets.
Things You Probably Don’t Know About Zebras
Facts about zebras, a group of equids with a distinct black and white striping pattern.
30 Groups of Birdies: The Basic Bird Groups
An introduction to the 30 basic groups of birds including birds of prey, buttonquails, gamebirds, herons, hummingbirds, owls, rheas, and many others.
Animals: Arthropods, Chordates, Molluscs,...
Profile of animals, multicellular organisms that are capable of locomotion and that rely on other organisms to obtain their nourishment.
The Basics of Vertebrate Evolution
An overview of vertebrate evolution that explores the key developments in the evolution of mammals, birds, reptiles, amphibians, and fish.
Learn About Lions
Profile of the lion, a species of large cat that has a buff colored coat, white underparts, and a long tail that ends in a black tuft of fur.
Learn the Basics About Birds
Birds are vertebrates that have four limbs, wings, feathers, hollow bones and other adaptations for an aerial lifestyle.
Fast Facts About Frogs
Learn interesting facts about frogs and find out about their diversity, evolutionary history and the characteristics make them different from other amphibian groups.
What Is Descent with Modification?
Descent with modification refers to the passing on of traits from parent organisms to their offspring.
Classification of Cats
Cats belong to the group of vertebrates known as mammals. Within the mammals cats are classified with other meat eaters in the Order Carnivora (known commonly as 'carnivores'). Page 3.
How to Choose the Right Binoculars
A guide to the different kinds of binoculars and their many features. Page 2.
Why You’re a Heterotroph
A heterotroph is an organism that is unable to obtain its carbon from carbon dioxide. Instead, heterotrophs obtain carbon from organic material such as other organisms, living or dead.
Elephant Trunk
Elephants' trunks are muscular, flexible extensions of their upper lip and nose. The tip of an African elephant's trunk has two fingerlike growths that enables them to grasp food and other small objects.
Vipers
Profile of vipers, a group of snakes that include true vipers, bush vipers, rattlesnakes, pit vipers, adders and night adders.
What to Know About Elephants
Profile of elephants, a group of mammals that are noted for their large size, massive skull, and long muscular trunk.
Get the Facts on Marsupials
Learn interesting facts about marsupials and find out about the characteristics make them different from other animal groups, their life cycle and their evolutionary history.
Why Species Have Niches
Definition of a niche, a term used to describe the role an organism or population plays within its community or ecosystem.
10 Interesting Facts About Arthropods
In this article, you'll learn interesting facts about arthropods and find out about their unique characteristics, their life cycle and their evolutionary history.
What Makes a Bird a Bird?
Bird characteristics include numerous adaptations for flight such as feathers, a furcula and hollow bones. This article explores the key characteristics that together distinguish birds from other animal groups.
How Waves and Tides Work
Waves give rhythm to the ocean. They transport energy over vast distances. Where they make landfall, waves help to sculpt a unique and dynamic mosaic of coastal habitats.
Cats
Cats inhabit a wide variety of habitats including coasts, deserts, forests, grasslands, and mountains.
Get Educated About Amphibians
Profile of amphibians, a group of vertebrates that includes frogs and toads, caecilians, and newts and salamanders.
Tiger Pictures
Tigers are the largest and most powerful of all cats. They are extremely agile despite their bulk and can leap between 8 and 10 meters in a single bound. They are also among the most recognizable of cats thanks to their distinct orange coat, black stripes and white markings.
Learn the Basic Reptile Groups
An introduction to the four basic groups of reptiles including crocodilians, lizards, snakes and turtles.
Sponges: Glass Sponges, Demosponges, and...
Profile of sponges, a group of simple aquatic invertebrates that include glass sponges, demisponges, and calcareous sponges.
Cats of Africa - Caracal, Serval, Cheetah,...
The cats of Africa include the caracal, serval, cheetah, lion, and leopard. Page 8.
Learn Your Animal Facts
Learn interesting facts about animals and find out about the characteristics make them different from other groups of living organisms.
Why Males and Females Look Different
Sexual dimorphism is the difference in form between male and female members of the same species.
Understanding Population Biology
Populations are groups of individuals belonging to the same species that live in a shared region at the same time.
The Largest Organisms on Earth
Giant sequoias, blue whales, Komodo dragons. Find out more about these and other sizable creatures in this article.
Plankton
Plankton are microscopic organisms that drift on the oceans' currents. They include organisms such as diatoms, dinoflagillates, krill, and copepods as well as the microscopic larva of crustaceans, sea urchins, and fish.
Bats
Bats are the worlds only group of mammals that have wings. This profile explores basic facts about bats including how they are classified, what they eat, where they live and the characteristics that make them different from other mammal groups.
Organ Systems in Animals
Animals' bodies are made up of various organ systems, groups of organs that work together to perform a function.
Learn Your Fish Groups
An introduction to the basic fish groups including bony fishes and cartilaginous fishes.
How Animals Interact with Their Environment
A first step to understanding individual animals, and in turn populations of animals, is to understand the relationship they have with their environment.
The Biggest Threats to Animals and Wildlife
Living things face a constant barrage of external stresses or threats that challenge their ability to survive and reproduce. If a species is unable to successfully cope with these threats through adaptation, they may face extinction.
Lion Portrait
Lions are the largest of all African cats. They are the second largest cat species worldwide, smaller than only the tiger.
What Is an Invertebrate?
Definition of invertebrate, an animal that lacks a backbone. Invertebrates account for more than 97% of all species alive today.
What You Should Know About Jellyfish
Profile of jellyfish, a group of carnivorous cnidarians with a bell-shaped body and tentacles.
How Vertebrates Moved Out of the Oceans
The vertebrates that underwent the evolutionary transition from life in water to life on land faced four basic adaptive challenges
Fast Facts About Fish
Learn interesting facts about fishes and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
The Parts of a Feather
Feathers are a unique adaptation of birds. Feathers are made up of keratin, an insoluble protein that is also found in mammalian hair and reptilian scales.
Defining Zoology
Zoology is the study of animals; yet this definition implies a simplicity that does not exist; instead, zoology is a complex discipline, drawing upon a diverse body of scientific observation and theory.
What to Know About Tigers
Profile of tigers, the largest and most powerful of all cats that have a distinct orange coat, black stripes and white markings.
Fact Sheet: Mouse-Like Rodents - Hamsters,...
Profile of mouse-like rodents, a group of rodents that includes rats, mice, voles, hamsters, lemmings, dormice, harvest mice, muskrats, and gerbils.
Florida Panther Pictures
Pictures of Florida panthers, an endangered subspecies of panther that scientists believe are healthier and fitter than they were fifteen years ago. They have higher genetic diversity, better immunity to disease, and fewer genetic abnormalities. They suffer fewer heart defects, enjoy higher fertility and are better able to climb trees.
The Crazy Things Reptiles Eat
What reptiles eat differs from species to species but here you'll find out about some of the general dietary trends within the four subgroups of reptiles.
Owl Pictures
Pictures of owls, including owl photos such as snowy owls, northern saw whet owls, great horned owls, barn owls and more.
Endangered Species FAQs
Endangered species are species that face a significant risk of extinction. Such species may be declining in number due to things such as habitat destruction, climate change, threats from invasive species.
10 Interesting Facts About Molluscs
Molluscs are invertebrates that include animals such as squid, octopuses, cuttlefish, nudibranchs, snails, slugs, limpets, sea hares, mussels, clams, oysters, scallops, as well as many lesser known creatures.
Animal Pictures - An A to Z List of Animal Photos
The following is an A to Z list of animal pictures available at this site, sorted alphabetically by common name.
What’s a Deciduous Forest?
Profile of the deciduous forest, a type of forest in which the trees shed their leaves during the cold months of the year.
World Wildlife Fund
The World Wildlife Fund (WWF) is a global-scale conservation organization that works in 100 countries and consists of nearly 5 million members worldwide.
Why Do Fireflies Glow?
Fireflies, also known as lightning bugs, glow to lure prey, discourage predators, and most importantly to attract mates.
Animal Profiles from A to Z
The following is an A to Z list of animal profiles available, sorted by animal group.
Learn About Appalachian Mountain Habitat
Profile of the Appalachian Mountain Range, an ancient band of mountains that stretches in a southwestern arc from Newfoundland to Alabama.
Bony Fishes: Ray-Finned Fishes and Lobe-Finned...
Profile of bony fishes, a group of vertebrates characterized by having a bony skeleton unlike the cartilaginous fishes whose skeleton consists of cartilage.
Threatened Species
A threatened species is a native species that is at risk of becoming endangered in the near future.
What You Should Know About African Elephants
Profile of the African elephant, the largest living land mammal and one three species of elephants alive today.
Invertebrates: The Animal Kingdom's Spineless...
Profile of invertebrates, animals that do not have a backbone or a bony skeleton.
Interesting Facts About Snowy Owls
Learn interesting facts about snowy owls and find out about the characteristics make them different from other owls, their life cycle and their evolutionary history.
Reptile Pictures
Pictures of reptiles, including reptile photos such as anoles, chamelons, geckos, alligators, turtles, snakes and more.
Fact Sheet: Rodents - Kangaroo Rats, Gophers,...
Profile of rodents, a group of mammals that includes squirrels, dormice, mice, rats, gerbils, beavers, gophers, kangaroo rats, pocket mice, and many others.
About Cheetahs, Lynxes, Caracal and Other Small...
The Subfamily Felinae, or the small cats, are a diverse group of carnivores. Page 4.
Cartilaginous Fish - Chondrichthyes - The...
Profile of cartilaginous fishes, a group of fishes that includes the largest and most formidable marine predators alive today -- sharks.
Insectivores: Moles, Moonrats and More
Insectivores are a group of mammals that include hedgehogs, moonrats, shrews, and moles. This profile explores basic facts about insectivores including how they are classified, what they eat, where they live and the characteristics that make them different from other mammal groups.
Invertebrate Pictures
Pictures of invertebrates including horseshoe crabs, jellyfish, ladybugs, snails, spiders, octopus, chambered nautiluses, mantises, and more.
Learn About Tasmanian devils, Numbats,...
Marsupials are a group of mammals that give birth to their young at an early stage of their development.
Primates: Lemurs, Lorises, Galagos, Monkeys,...
Primates form a diverse group of mammals that includes about 233 species that are grouped into 13 families.
Apes
Apes are a group of primates that include gorillas, chimpanzees, orangutans and gibbons. This profile explores basic facts about apes including how they are classified, what they eat, where they live and the characteristics that make them different from other primate.
Amphibian Pictures
Pictures of amphibians including red-eyed tree frogs, axolotl, green tree frogs, California newts, leopard frogs, and more.
New World Monkeys - Platyrrhini - The Animal...
New World Monkeys are a group of primates endemic to Central and South America. New world monkeys include marmosets, tamarins, capuchins, squirrel monkeys, night monkeys, owl monkeys, titis, sakis, uakaris, howler monkeys, spider monkeys, woolly spider monkeys, and woolly monkeys.
How Communities and Ecosystems Interact
The natural world is characterized by many complex interactions. Individuals belong, in turn, to populations, species, communities, and ecosystems.
Perching Birds: Wagtails, Swallows, Crowas,...
Profile of perching birds, a group of birds known for their specialized feet and the complex vocalizations and songs.
Mammal Pictures
Pictures of mammals, including mammal photos such as pronghorn, meerkats lions, koalas, hippopotamuses, dolphins and more.
Facts About Molluscs
Molluscs are a group of invertebrates known for their remarkable diversity—both sheer number of species as well as variety of form. Learn interesting facts about mollusks and find out about the characteristics make them different from other animal groups.
Learn About Babirusas, Pigs, Warthogs, and More
Hogs and pigs, also known as suids, are a group of mammals that includes babirusas, pigs, warthogs, forest hogs, red river pigs, and bushpigs. The Family Suidae also includes the domestic pig, Sus scrofa. The Family Suidae is subdivided into eight genera containing a total of sixteen species of pigs.
Turtles: From Side-Necked Turtles to Hidden-Nec...
Profile of turtles, a group of reptiles best known for the hard shell which is a modification of their ribcage and vertebral column.
What Is Desertification?
Desertification is the development of desert-like conditions in regions that have experienced human disturbance such as deforestation, overgrazing, or poorly managed agriculture.
The Anatomy of a Cell
The cell is a fundamental component of our modern definition of life and living things. The cell is regarded as the basic building block of life and is used in the elusive definition of what it means to be 'alive'.
Polar Bear
The polar bear is among the largest land carnivores, comparable in size only to the brown bear. Polar bears weigh in the range of 400kg-680kg (880lb-1500lb) and are 2.1m-3.3m (7ft-11ft) in length.
From Forest Floor to Canopy: The Layers of a...
Mature forests often have several distinct layers including the forest floor, herb layer, shrub layer, understory, canopy, and emergents.
The Nature Conservancy
Profile of The Nature Conservancy, a conservation group that works with governments, communities, and others to solve conservation challenges.
How Animals and Wildlife are Classified
For centuries, the naming and classification of living organisms into groups has been an integral part of the study of nature.
Learn About the Arctic Wolf
Profile of the Arctic wolf, a subspecies of grey wolf that lives in the Canadian Arctic, Alaska, and northern Greenland.
Leopard
Profile of the leopard, a large cat that has a pale, cream-yellow coat with solid black spots.
Snow Leopard Pictures
Snow leopards are mountain-dwelling cats that live throughout the ranges of South and Central Asia at altitudes between 9,800 and 16,500 feet. Snow leopards are classified as endangered and their population is declining due to habitat destruction and a dwindling prey base.
Vertebrate - Zoology Glossary Definition
A vertebrate is an animal that has cartilaginous or bony vertebrae that surround a nerve cord and a skull that protects the brain.
Can You Define Evolution?
The term evolution is defined as simply change over time. But when applied to lifeforms, the term evolution--or more precisely biological evolution--takes on an added dimension of meaning. Biological evolution is defined as descent with modification.
Frogs and Toads: The Most Diverse Group of...
Frogs and toads are amphibians that have no tail, a large head, large eyes, and long, powerful hind legs. This profile explores basic facts about frogs and toads including how they are classified, what they eat, where they live and the characteristics that make them different from other amphibian groups.
The Wild Side of Animal Senses
Man-made radars and infrared detectors help humans to stretch beyond the five senses. However, animals had these extra senses first. Read about all of them.
Ostrich Pictures
The ostrich is the tallest and heaviest species of all living birds. Although its bulky body means that flying is out of the question, the ostrich has adapted to life on the ground with impressive agility.
An Overview of Events That Have Shaped Life on...
To better understand the animals that inhabit our present-day world, it helps to examine the organisms that have lived throughout the history of our planet.
Pigeons and Doves
This profile explores basic facts about pigeons and doves including how they are classified, what they eat, where they live and the characteristics that make them different from other bird groups.
Facts About Carnivores
Learn interesting facts about carnivores and find out about the characteristics make them different from other mammals, their life cycle and their evolutionary history.
Lion Silhouette
The life of a male lion is socially more precarious than that of a female lion. Males must win their way into a pride of females and once they do they must fend off challenges from males outside the pride who try to take their place. Page 5.
What Are Fish?
The term fish is used to refer to any aquatic vertebrate that has a skin covered with scales, two sets of paired fins, some unpaired fins, and a set of gills.
Aquatic Biome: Tropical Reefs, Brackish...
Profile of the aquatic biome, a biome that consists of habitats around the world that are dominated by water--from tropical reefs, to brackish mangroves, to Arctic lakes.
You can opt-out at any time. Please refer to our privacy policy for contact information.

©2014 About.com. All rights reserved.