Animals / Wildlife: Most Popular Articles
An introduction to the six basic groups of animals including amphibians, birds, fishes, invertebrates, mammals, and reptiles.
A list of the largest species in each group of mammals that inhabit our planet today.
An A to Z list of animal profiles available in The Animal Encyclopedia, sorted alphabetically by scientific name.
An A to Z list of animal profiles available in The Animal Encyclopedia, sorted alphabetically by common name.
A list of my top ten favorite conservation organizations that work to protect animals and wildlife around the world.
Facts about owls, a group of birds known for their distinct calls, nocturnal habits, and silent flight.
The following is an A to Z list of mammal profiles available, sorted alphabetically.
A list of simple things you can do to help protect animals and wildlife.
A list of some of the animals that inhabit North America including the nine-banded armadillo, tufted titmouse, caribou, monarch butterfly, and more.
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.
Learn about the key characteristics of animals including multicellularity, eukaryotic cells, sexual reproduction, movement, and more.
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.
Learn about the key characteristics of mammals including mammary glands, hair, endothermy, diphyodonty, and more.
A list of ten animals of the Amazon River basin in South America including harpy eagles, three-toed sloths, toucans, and more.
A list of some of the animals that inhabit the Great Barrier Reef including sea birds, mollusks, marine mammals, marine reptiles, and more.
Facts about bears, a group of carnivores known for their burly build, impressive agility and, in some species, their winter sleep habits.
An introduction to the basic mammal groups including aardvarks, bats, carnivores, cetaceans, elephants, marsupials, primates, rodents, and many others.
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.
Profile of arthropods, a group of invertebrates that includes insects, spiders, crustaceans, scorpions, centipedes, and many others.
From clouds of ink to chromatophores, there's more to octopi than eight arms.
A brief overview of the history of life from the time the first life evolved until the present day. Page 2.
In this photographic guide, find out more about cats, their classification, adaptations, and natural history.
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.
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.
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.
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.
Profile of mammal, a group of four-legged vertebrates that have hair, a four chambered heart and mammary glands.
Animals' bodies are made up of various organ systems, groups of organs that work together to perform a function.
Profile of echinoderms, a diverse group of marine invertebrates comprising approximately 6000 species.
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.
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.
One criteria by which all animals are described is whether or not they have a backbone. This article explores facts about vertebrates and invertebrates.
An introduction to six basic groups of invertebrates including arthropods, cnidarians, echinoderms, mollusks, segmented worms, and sponges.
An article examining how scientists estimate and count the number of animals that live on our planet today.
Profile of molluscs, a group of invertebrates that includes squid, octopuses, cuttlefish, nudibranchs, snails, slugs, limpets, mussels, and many more.
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.
Profile of carnivores, a group of mammals that includes dogs and their relatives, bears, racoons, mustelids, civits, hyenas, aardwolf, and cats.
Definition of habitat destruction, a term that is used to describe the process by which natural habitat is damaged or destroyed.
Endangered animals are species or populations that are at risk of becoming extinct.
What is a reptile? To answer this question, we must understand the characteristics of reptiles - such as amniotic eggs, scales and ectothermy.
Learn interesting facts about mammals and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Profile of reptiles, a group of vertebrates that colonized terrestrial habitats more extensively than their amphibian ancestors.
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.
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.
The most recognized image of a jellyfish is that of the adult jellyfish, with its bell-shaped body and long tentacles.
Learn interesting facts about invertebrates and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Learn interesting facts about reptiles and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Profile of insects, a highly successful group of animals that accounts for more species of animals than any other class of animals.
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.
The term species can be defined as a group of individual organisms that are capable of interbreeding to produce fertile offspring in nature.
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.
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.
Profile of chordate, a group of animals that includes vertebrates, tunicates, lancelets.
Learn facts about frogs and find out about their diversity, evolutionary history and the characteristics make them different from other vertebrates.
Birds are vertebrates that have four limbs, wings, feathers, hollow bones and other adaptations for an aerial lifestyle.
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.
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.
Profile of sponges, a group of simple aquatic invertebrates that include glass sponges, demisponges, and calcareous sponges.
Profile of animals, multicellular organisms that are capable of locomotion and that rely on other organisms to obtain their nourishment.
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.
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.
The natural world is characterized by many complex interactions. Individuals belong, in turn, to populations, species, communities, and ecosystems.
Learn interesting facts about frogs and find out about their diversity, evolutionary history and the characteristics make them different from other amphibian groups.
The critically endangered black rhinoceros (Diceros bicornis) inhabits eastern and southern Africa. The black rhinoceros has poor eyesight but acute hearing and sense of smell. It has a hooked upper lip that enables it to grasp vegetation and strip leaves from stems and branches.
An introduction to the three basic groups of amphibians including salamanders and newts, caecilians, and frogs and toads.
Populations are groups of individuals belonging to the same species that live in a shared region at the same time.
An overview of vertebrate evolution that explores the key developments in the evolution of mammals, birds, reptiles, amphibians, and fish.
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.
A first step to understanding individual animals, and in turn populations of animals, is to understand the relationship they have with their environment.
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.
Profile of vipers, a group of snakes that include true vipers, bush vipers, rattlesnakes, pit vipers, adders and night adders.
Profile of elephants, a group of mammals that are noted for their large size, massive skull, and long muscular trunk.
Descent with modification refers to the passing on of traits from parent organisms to their offspring.
The vertebrates that underwent the evolutionary transition from life in water to life on land faced four basic adaptive challenges
Facts about zebras, a group of equids with a distinct black and white striping pattern.
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 interesting facts about fishes and find out about their diversity, evolutionary history and the characteristics make them different from other animal groups.
Definition of a niche, a term used to describe the role an organism or population plays within its community or ecosystem.
Profile of cartilaginous fishes, a group of fishes that includes the largest and most formidable marine predators alive today -- sharks.
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.
Profile of amphibians, a group of vertebrates that includes frogs and toads, caecilians, and newts and salamanders.
Profile of mouse-like rodents, a group of rodents that includes rats, mice, voles, hamsters, lemmings, dormice, harvest mice, muskrats, and gerbils.
An introduction to the 30 basic groups of birds including birds of prey, buttonquails, gamebirds, herons, hummingbirds, owls, rheas, and many others.
A guide to the different kinds of binoculars and their many features. Page 2.
Pictures of mammals, including mammal photos such as pronghorn, meerkats lions, koalas, hippopotamuses, dolphins and more.
Profile of tigers, the largest and most powerful of all cats that have a distinct orange coat, black stripes and white markings.
Cats inhabit a wide variety of habitats including coasts, deserts, forests, grasslands, and mountains.
In this article, you'll learn interesting facts about arthropods and find out about their unique characteristics, their life cycle and their evolutionary history.
Pictures of invertebrates including horseshoe crabs, jellyfish, ladybugs, snails, spiders, octopus, chambered nautiluses, mantises, and more.
Pictures of reptiles, including reptile photos such as anoles, chamelons, geckos, alligators, turtles, snakes and more.
Monotremes are a group of mammals that include echidnas and the platypus. This profile explores basic facts about monotremes including how they are classified, what they eat, where they live and the characteristics that make them different from other mammal groups.
An introduction to the four basic groups of reptiles including crocodilians, lizards, snakes and turtles.
Desertification is the development of desert-like conditions in regions that have experienced human disturbance such as deforestation, overgrazing, or poorly managed agriculture.
Profile of the deciduous forest, a type of forest in which the trees shed their leaves during the cold months of the year.
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.
To understand animals and their biology, it helps to understand the cells, tissues, organs and organ systems that comprise them.
Learn interesting facts about animals and find out about the characteristics make them different from other groups of living organisms.
Sexual dimorphism is the difference in form between male and female members of the same species.
The cats of Africa include the caracal, serval, cheetah, lion, and leopard. Page 8.
Profile of the Appalachian Mountain Range, an ancient band of mountains that stretches in a southwestern arc from Newfoundland to Alabama.
Profile of perching birds, a group of birds known for their specialized feet and the complex vocalizations and songs.
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.
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.
Pictures of amphibians including red-eyed tree frogs, axolotl, green tree frogs, California newts, leopard frogs, and more.
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.
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.
Charles Darwin was born in Shrewsbury, England on February 12, 1809, the fourth child of Robert Waring Darwin and Susannah Wedgwood.
Giant sequoias, blue whales, Komodo dragons. Find out more about these and other sizable creatures in this article.
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.
The following is an A to Z list of animal profiles available, sorted by animal group.
Profile of jellyfish, a group of carnivorous cnidarians with a bell-shaped body and tentacles.
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.
Profile of bony fishes, a group of vertebrates characterized by having a bony skeleton unlike the cartilaginous fishes whose skeleton consists of cartilage.
For centuries, the naming and classification of living organisms into groups has been an integral part of the study of nature.
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.
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'.
Lions are the largest of all African cats. They are the second largest cat species worldwide, smaller than only the tiger.
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.
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.
Profile of the African elephant, the largest living land mammal and one three species of elephants alive today.
An introduction to the basic fish groups including bony fishes and cartilaginous fishes.
Definition of the scientific method, a series of steps scientists take to acquire, test, and describe the natural world.
This profile explores basic facts about hares, rabbits and pike including how they are classified, what they eat, where they live and the characteristics that make them different from other mammal groups.
Profile of The Nature Conservancy, a conservation group that works with governments, communities, and others to solve conservation challenges.
Profile of turtles, a group of reptiles best known for the hard shell which is a modification of their ribcage and vertebral column.
Profile of bivalves, a group of molluscs that include clams, scallops, oysters, mussels, borers, trough shells and many others.
Pictures of owls, including owl photos such as snowy owls, northern saw whet owls, great horned owls, barn owls and more.
Profile of the Arctic wolf, a subspecies of grey wolf that lives in the Canadian Arctic, Alaska, and northern Greenland.
Marsupials are a group of mammals that give birth to their young at an early stage of their development.
Profile of armadillos, sloths, and anteaters, a group of mammals that are notable for the unique joints in their backbone.
Second page of 10-part introduction on cats. This part discusses traits, like claws, of the cat that make them adapt to many environments.
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.
The Wildlife Conservation Society (WCS) supports zoos and aquariums while promoting environmental education and conservation of wild populations and their habitats.
The World Wildlife Fund (WWF) is a global-scale conservation organization that works in 100 countries and consists of nearly 5 million members worldwide.
Learn interesting facts about carnivores and find out about the characteristics make them different from other mammals, their life cycle and their evolutionary history.
A threatened species is a native species that is at risk of becoming endangered in the near future.
The following is an A to Z list of animal pictures available at this site, sorted alphabetically by common name.
Primates form a diverse group of mammals that includes about 233 species that are grouped into 13 families.
Even-toed hoofed mammals include 225 species.
Profile of owls, a group of birds that have strong talons, a downward-curved bill, acute hearing, and keen eyesight.
Profile of invertebrates, animals that do not have a backbone or a bony skeleton.
Profile of the American beaver, one of two living species of beavers and the world's second largest rodent, only the capybara of South America is larger.
Vertebrates are a group of chordates that includes lampreys, mammals, birds, amphibians, reptiles and fishes.
Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles.
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.
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.
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.
Gorillas are a group of great apes that includes two species, the eastern gorilla and the western gorilla. Learn interesting facts about gorillas and find out what makes them unique.
Segmented worms are bilaterally symmetrical invertebrates that include more than 12,000 species such as earthworms, ragworms and leeches. This profile explores basic facts about segmented worms including how they are classified, what they eat, where they live and the characteristics that make them different from other invertebrate groups.
Mature forests often have several distinct layers including the forest floor, herb layer, shrub layer, understory, canopy, and emergents.