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Animals/Wildlife: Most Popular Articles

These articles are the most popular over the last month.
10 Facts About Owls
Facts about owls, a group of birds known for their distinct calls, nocturnal habits, and silent flight.
The 6 Basic Animal Groups
An introduction to the six basic groups of animals including amphibians, birds, fishes, invertebrates, mammals, and reptiles.
Comparing Prokaryote and Eukaryote Cells
All living organisms can be sorted into one of two groups depending on the fundamental structure of their cells - prokaryotes or eukaryotes.
Top 10 Wildlife Conservation Organizations
A list of my top ten favorite conservation organizations that work to protect animals and wildlife around the world.
10 Simple Things You Can Do to Protect Animals
It's easy to feel overwhelmed in the face of species loss and habitat destruction. Here is a list of things you can do to help protect wildlife.
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.
Animals: Key Characteristics
Learn about the key characteristics of animals including multicellularity, eukaryotic cells, sexual reproduction, movement, and more.
Mammal Profiles: By Common Name
The following is an A to Z list of mammal profiles available, sorted alphabetically by common name.
The 6 Basic Invertebrate Groups
An introduction to six basic groups of invertebrates including arthropods, cnidarians, echinoderms, mollusks, segmented worms, and sponges.
10 Facts 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.
10 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.
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.
Animals of the Great Barrier Reef
A list of some of the animals that inhabit the Great Barrier Reef including sea birds, mollusks, marine mammals, marine reptiles, and more.
The Largest Mammals
A list of the largest species in each group of mammals that inhabit our planet today.
Mammals: Key Characteristics
Mammals display a remarkable array of adaptations, some of which (hair, mammary glands, specialized ear bones) are shared by no other animal groups.
10 Facts About Invertebrates
Learn interesting facts about invertebrates, a group of animals that accounts for 97 percent of all known species.
10 Facts 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.
Arthropods: Centipedes, Millipedes, Spiders,...
Profile of arthropods, a group of invertebrates that includes insects, spiders, crustaceans, scorpions, centipedes, and many others.
The 21 Basic Mammal Groups
An introduction to the basic mammal groups including aardvarks, bats, carnivores, cetaceans, elephants, marsupials, primates, rodents, and many others.
Animal Profiles: By Common Name
An A to Z list of animal profiles available in The Animal Encyclopedia, sorted alphabetically by common name.
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.
Facts About Great Horned Owls
Great horned owls are a large species of true owls that inhabits many parts of North and South America.
What's a Cnidarian?
Cnidarians are diverse and come in many shapes and sizes but there are some basic anatomical features that most members of the group share in common.
10 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.
10 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.
10 Facts About Amphibians
Learn facts about frogs and find out about their diversity, evolutionary history and the characteristics make them different from other vertebrates.
Molluscs: Fact Sheet
Molluscs are a group of invertebrates that includes squids, octopuses, cuttlefishes, nudibranchs, snails, slugs, limpets, mussels, and many more.
Amazon River Basin Animals
A list of animals of the Amazon River basin in South America including harpy eagles, three-toed sloths, toucans, and more.
What Is Descent with Modification?
Descent with modification refers to the passing on of traits from parent organisms to their offspring.
Mammals: The Furry Vertebrates
Mammals are a group of tetrapods that includes bats, carnivores, cetaceans, elephants, hoofed mammals, primates, monotremes, marsupials, and rodents.
10 Facts About Jellyfish
Jellyfish get a lot of negative press for the threats they can pose to swimmers and holiday makers visiting beaches around the world.
10 Facts About Reptiles
Reptiles are cold-blooded vertebrates that diverged from ancestral amphibians about 340 million years ago.
Reptiles: Key Characteristics
Explore the basic characteristics that are shared by all reptiles—from snakes and lizards to crocodiles and turtles.
11 Facts About Octopuses
Octopuses are known for their intelligence, their uncanny ability to blend into their surroundings and the unique way they get around.
Endangered Animals
Endangered animals are species or populations that are at risk of becoming extinct.
10 Facts About Arthropods
Learn interesting facts about arthropods, a group of invertebrates that have an exoskeleton and a segmented body.
Lions, Tigers, Leopards, Cheetahs and Other Cats
In this photographic guide, find out more about cats, their classification, adaptations, and natural history.
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.
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.
Learn About the Stages in a Frog's Life
The life cycle of a frog includes three stages: egg, larva, and adult. This article explores the developmental changes a frog experiences in its life.
Evolution: The Basics and Beyond
A brief overview of the history of life from the time the first life evolved until the present day. Page 2.
Interesting Facts About Snowy Owls
Snowy owls are large owls with white plumage and their extreme northerly range which includes tundra habitat throughout Alaska, Canada and Eurasia.
The Key to Keystone Species
A keystone species is a species that plays a critical role in the structure of an ecological community and whose influence is greater than expected.
The 4 Basic Amphibian Groups
An introduction to the three basic groups of amphibians including salamanders and newts, caecilians, and frogs and toads.
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.
Tiger: Fact Sheet
Tigers are the largest and most powerful of all cats. Tigers have a distinct orange coat, black stripes and white markings.
10 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.
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.
Organ Systems in Animals
Animals' bodies are made up of various organ systems, groups of organs that work together to perform a function.
Animals: Fact Sheet
Animals are multicellular organisms that are capable of locomotion and that rely on other organisms to obtain their nourishment.
A Guide to Vertebrates and 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.
How Communities and Ecosystems Interact
The natural world is characterized by many complex interactions. Individuals belong, in turn, to populations, species, communities, and ecosystems.
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.
How Many Animal Species Are There on Earth?
Find out how scientists estimate and count the many millions of animal species that live on our planet today.
Why Males and Females Look Different
Sexual dimorphism is the difference in form between male and female members of the same species.
Aquatic Biome: Tropical Reefs, Brackish...
The aquatic biome consists of habitats around the world that are dominated by water, from tropical reefs, to brackish mangroves, to Arctic lakes.
Carnivores: The Mammals That Hunt
Carnivores are a group of mammals that includes dogs and their relatives, bears, racoons, mustelids, civits, hyenas, aardwolf, and cats.
A Guide to Cats
Second page of 10-part introduction on cats. This part discusses traits, like claws, of the cat that make them adapt to many environments.
10 Facts About Animals
Learn interesting facts about animals and find out about the characteristics make them different from other groups of living organisms.
Chordates: Bilaterally Symmetrical Critters
Chordates are a group of animals that includes more than 75,000 species. Chordates are divided into three groups: vertebrates, tunicates, lancelets.
10 Facts About Zebras
Facts about zebras, a group of equids with a distinct black and white striping pattern.
Lion: Fact Sheet
The lion is 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.
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.
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.
Insects: The Most Diverse of All Animal Groups
Profile of insects, a highly successful group of animals that accounts for more species of animals than any other class of animals.
The 30 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.
10 Facts About 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.
Net Primary Production
Net primary production (NPP) is the total energy (or nutrients) accumulated by an ecological unit of interest (such as an organism, a population, or an entire community).
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.
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.
The 4 Basic Reptile Groups
An introduction to the four basic groups of reptiles including crocodilians, lizards, snakes and turtles.
Reptiles: Cold-Blooded Yet Charismatic
Reptiles are a group of vertebrates that colonized terrestrial habitats more extensively than their amphibian ancestors.
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.
Echinoderms: Famous For Their Five-Point Symmetry
Echinoderms are a group of marine invertebrates that includes star fish, sea lilies, feather stars, brittle stars, sea cucumbers and sea urchins.
Population Biology Basics
Populations are groups of individuals belonging to the same species that live in a shared region at the same time.
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.
Birds: Key Characteristics
Bird characteristics include numerous adaptations for flight such as feathers, a furcula and hollow bones.
10 Facts About Fishes
Learn interesting facts about fishes and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
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.
Sponges: Glass Sponges, Demosponges, and...
Sponges are a group of simple aquatic invertebrates that include glass sponges, demisponges, and calcareous sponges.
What You Should Know About Jellyfish
Jellyfish are a group of carnivorous cnidarians with a bell-shaped body and tentacles. Jellyfish are delicate, soft-bodied animals.
10 Facts About Carnivores
Canids are long-legged carnivores that include wolves, coyotes, jackals, foxes, wild dogs and domestic dogs.
Vipers: The Notorious, Venomous, Long-Fanged...
Vipers are a group of snakes that include true vipers, bush vipers, rattlesnakes, pit vipers, adders and night adders.
Feathers: Their Structure and Function
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.
What Do Reptiles Eat?
What reptiles eat differs from species to species but here you'll find out about some of the general dietary trends for various reptiles.
The Biggest Threats to Animals and Wildlife
Living organisms face a constant barrage of external stresses or threats that challenge their ability to survive and reproduce.
Mammal Pictures
Pictures of mammals, including mammal photos such as pronghorn, meerkats lions, koalas, hippopotamuses, dolphins 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.
Fast Facts About Frogs
Learn interesting facts about frogs and find out about their diversity, evolutionary history and the what make them different from other amphibians.
Invertebrate Pictures
Pictures of invertebrates including horseshoe crabs, jellyfish, ladybugs, snails, spiders, octopus, chambered nautiluses, mantises, and more.
Elephants: Fact Sheet
Elephants are a group of mammals that are noted for their large size, massive skull, and long muscular trunk.
Cats of Africa - Caracal, Serval, Cheetah,...
The cats of Africa include the caracal, serval, cheetah, lion, and leopard. Page 8.
The Nature Conservancy
The Nature Conservancy is a conservation group that works with governments, communities, and others to solve conservation challenges.
Endangered Species: Frequently Asked Questions
Endangered species are at risk of extinction due to threats such as habitat destruction, climate change, or the ill effects of invasive species.
Amphibians: The First Vertebrates to Venture...
Amphibians are a group of tetrapods that include modern-day frogs and toads, caecilians, and newts and salamanders.
Animals and Their Environment
A first step to understanding individual animals and populations of animals is to understand the relationship they have with their environment.
Cartilaginous Fish: Fact Sheet
Cartilaginous fishes are a group of fishes that includes the largest and most formidable marine predators alive today: the sharks.
Quiz - 6 Basic Animal Groups
Put your animal identification skills to the test in this quiz.
Learn About the Arctic Wolf
The Arctic wolf is a subspecies of grey wolf that lives in the Canadian Arctic, Alaska, and northern Greenland.
World Wildlife Fund
The World Wildlife Fund is a global-scale conservation organization that works in 100 countries and consists of nearly 5 million members worldwide.
The 5 Basic Biomes of the World
Biomes are large regions of the earth that share similar characteristics such as climate, soils, precipitation, plants, and animals.
Owl Pictures
Pictures of owls, including owl photos such as snowy owls, northern saw whet owls, great horned owls, barn owls and more.
Segmented Worms: More Than Merely Earthworms
Segmented worms are bilaterally symmetrical invertebrates that include more than 12,000 species such as earthworms, ragworms and leeches.
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.
Birds: Our Fine Feathered Friends
Birds are vertebrates that have four limbs, wings, feathers, hollow bones and other adaptations for an aerial lifestyle.
Cats of Asia - Snow Leopard, Clouded Leopard,...
Snow leopards live in mountainous habitat at elevations of between 2000 and 6000 meters. Their range extends from northwestern China to Tibet and the Himalayas. Page 10.
Owls
Owls are a group of birds that have strong talons, a downward-curved bill, acute hearing, and keen eyesight.
The 3 Basic Fish Groups
An introduction to the basic fish groups including bony fishes and cartilaginous fishes.
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.
Black Rhinoceros: Fact Sheet
The black rhinoceros is a critically endangered species of rhinoceros, It has poor eyesight but acute hearing and sense of smell.
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.
Wildlife Conservation Society
The Wildlife Conservation Society supports zoos and aquariums while promoting environmental education and conservation of wildlife and habitats.
Gross Primary Production
The total energy (or nutrients) assimilated by an ecological unit (such as an organism, a population, or an entire community).
The Cheetah - A Unique Cat
The Cheetah (Acinonyx jubatus) is a highly unusual cat that has numerous characteristics that set it apart from all other cats. Page 11.
Bats: Fact Sheet
Bats are the worlds only group of mammals that have wings.
Amphibian Pictures
Pictures of amphibians including red-eyed tree frogs, axolotl, green tree frogs, California newts, leopard frogs, and more.
Mammal Profiles - An A to Z List of Mammals
The following is an A to Z list of mammal profiles available, sorted alphabetically by scientific name.
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.
Starfish: The Stellar Echinoderms
Starfish are a group of echinoderms that include about 1500 living species. Starfish have five or more arms that radiate outward from a central body disc.
American Black Bear: Fact Sheet
The American black bear is a large carnivore that inhabits the forests, swamps, tundra throughout the more northerly reaches of North America.
About Elephants' Trunks
Elephants' trunks are muscular, flexible extensions of their upper lip and nose. To drink, elephants suck water up into their trunk
What Is a Rain Shadow?
A rain shadow is an area of dry land on the leeward side of a mountain. This profile explores the geography, habitat, and wildlife of rain shadows.
Invertebrates: The Animal Kingdom's Spineless...
Scientists have identified nearly one million living species of invertebrates, but this is only a small fraction of the invertebrates alive today.
How to Tell the Panthera Species Apart
The identification of the various panthera species (or 'roaring cats') can be confusing but armed with a few facts, you can quickly narrow down the possibilities when trying to place a name with a cat. Page 9.
How to Choose the Right Binoculars
A guide to the different kinds of binocular technology and their many features and how to select what you need for quality, comfort, ease, and price.
Mammalian Temperature Regulation
To maintain correct body temperature, mammals must conserve body heat in cold conditions and dissipate extra body heat in warmer conditions.
What Are the Largest Organisms on Earth?
Giant sequoias, blue whales, Komodo dragons, and African elephants all share the distinction of being among the world's largest organisms.
How Do Species Interact?
Wildlife species interact with each other in numerous, complex ways. Fortunately, we can make some general statements about these interactions.
Squamates: The Flexible-Jawed Reptiles
Squamates are a group of reptiles that sheds their skin periodically in patches and have uniquely jointed skulls and jaws.
European Robin: Fact Sheet
The European robin is a small perching bird that lives throughout Europe and is noted for its orange-red breast.
Pentaradial Symmetry
Definition of pentaradial, a term that describes a type of radial symmetry in which body parts are arranged along five rays of symmetry.
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.
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.
Black Jaguar
In some cat species, a melanistic or black color morph appears on occasion in a wild population. Although these melanistic individuals may look quite different from their kin, they are color variations, not separate species. Examples of such melanistic individuals include black leopards and black jaguars. This picture shows a black jaguar. Page 10.
Butterfly
Butterflies are a group of insects that include more than 15,000 species. Members of this group include swallowtail butterflies, birdwing butterflies, white butterflies, yellow butterflies, blue butterflies, copper butterflies, metalmark butterflies, brushfooted butterflies, and skippers. Page 2.
American Beaver: Fact Sheet
The American beaver is one of two living species of beavers and the world's second largest rodent, only the capybara of South America is larger.
Storming the Beaches: Tetrapods And The Tricky...
During the Devonian Period, about 375 million years ago, a group of vertebrates clamoured their way out of the water and onto land.
White Tiger
In addition to melanistic individuals, some cat species also exhibit white color varieties. White tigers and white lions are two such examples. Neither white tigers nor white lions are albinos, but instead are white due to the presence of a recessive gene which causes their coat background color to be almost white instead of yellow. Page 11.
Bivalves: Clams, Scallops, Cockles and More
Bivalves are a group of molluscs that include clams, scallops, oysters, mussels, borers, trough shells and many others.
The Amazing Jumping Spider
Jumping spiders are a group of arachnids that have eight eyes: four on the front of their head, two on the side, and two on the rear of their head.
Animal Cells, Tissues, Organs and Organ Systems
To understand animals and their biology, it helps to understand the cells, tissues, organs and organ systems that comprise them.
African Elephant: Fact Sheet
The African elephant is the largest living land mammal and one three species of elephants alive today.
Bird Pictures
Pictures of birds including vultures, puffins, jays, cranes, sandgrouse, robins, gannets, plovers and more.
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.
The Temperate Forests
Temperate forests evolved 65 million years ago when global temperatures dropped and, in areas further from the equator, cooler climates emerged.
North and South American Cats
Pumas, also known as mountain lions, catamonts, panthers or cougars, are a large cat whose former range extended from coast to coast across North America. By 1960, they were declared extinct in most midwestern and eastern ranges. Page 7.
Bony Fishes: Fact Sheet
Profile of bony fishes, a group of vertebrates characterized by having a bony skeleton unlike the cartilaginous fishes whose skeleton consists of cartilage.
Lion and Tiger Subspecies
There are numerous lion subspecies and there is disagreement among experts as to which subspecies are recognized. Page 6.
Why Are Amphibians in Decline?
In recent years, scientists and conservationists have been working to raise public awareness of a global decline in amphibian populations.
Prokaryote
Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles.
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