What Are Habitats? A habitat is the immediate environment in which a living organism (an animal or plant), exists. A habitat can exist in any size and can even be as small as a rock pool or a log that is decaying on the forest floor. The word habitat however, generally refers to the grouping of animals and plants, together with their surroundings. Habitats contain both living organisms and non-living objects and can contain anywhere from just a few species to thousands of them, all coexisting in a very small space. Factors That Shape Habitats Geology has the most fundamental influence on the creating of habitats, along with climate. Mountain ranges, deserts and rainforests are all shaped by the changes beneath the surface of the earth and then rely on the climate to make them come alive. Habitats can vary from the enormous wet oceans, to the arid, dry deserts and are found everywhere you look on Earth. Temperature and rainfall are two of the biggest climatic factors that help to shape habitats, and changes in these factors can have devastating effects on habitats and animals all around the world (such as
the ice melting in the polar regions).
Biodiversity For years now, the incredible variety of species (and the variety within species) has fascinated scientists all around the world. It has been noted that the greatest levels of species richness are in the regions surrounding the Equator, and the lowest levels of biodiversity are found at the poles.
Animal Distribution Habitats are spread across enormous areas of the world such as the South American Amazon Rainforest which covers 5,500,000 km2, while the African Sahara Desert covers 8,600,000 km2 both of which are enormous regions of the planet. Animals however, are not spread out across the earth so evenly as many are still inhabiting the same regions where they first evolved millions of years ago. The colder parts of the world, such as the polar regions have little in the way of species variation as animals inhabiting these areas must be specially adapted to the cold. However, what the polar regions lack in biodiversity they make up for in population numbers as the Antarctic Ocean is home to millions and millions of crab-eater seals, which are the most numerous large mammals on the planet. Some animals are also distributed around the world in accordance with the plants that grow there, as certain species of animal must eat certain species of plant (like a giant panda needing to inhabit areas where bamboo grows). Animals have basic needs for air, water, food, shelter, and space. Plants, animals, and even humans choose habitats for many different reasons, depending on their needs. The picture to the right shows different animals and the
habitat that best fits its needs. Animals live in habitats all over that are suited for them. Some of these habitats include: Grasslands, Rainforests, Deserts, and Arctic Tundra Humans help animals by providing habitats for them as well. Some people build dams in the water to create new habitats for fish, while others take in pets, like dogs and cats, and provide habitats for them in their homes.
Animals have a variety of similarities and differences; some are alike in what they look like, what they do, what they eat, and where they live; while others are very different from one another. Many animals share the same habitat because they are from the same group. The picture below shows different habitats with different
animals in each one.
Scientists divide animals into groups, depending upon how they are alike and different. Six common groups of animals are: Birds: Found across the world, birds range from small and difficult-to-spot songbirds to the majestic bald eagle. Fish: Fish have more recognized species than any other vertebrate and their habitats range from the smallest freshwater streams to the deepest seafloor canyons. Reptiles: The majority of reptiles are unable to internally regulate their body temperature and so live in temperate and tropical climates. Amphibians: The first vertebrates to colonize terrestrial habitats, amphibians remain closely tied to water. Mammals: after the extinction of dinosaurs around 65 million years ago, mammals diversified to fill the many vacated niches in a wide range of habitats. Insects: Insects are the most diverse group of animals on the planet.