A habitat is a special place where a plant or animal lives. Just like you have a home or place to live, so do animals and plants. When we talk about an animal's or a plant's home it is more like a neighborhood than a “house.” An animal needs five things to survive in its habitat:
Animals require different amounts of space. Habitats can be big like a forest or they can be much smaller like a burrow. Some animals defend a huge territory or roam over a large area. Some other animals need only a small amount of space and can put up with neighbors that live close by.
Just like you have to go to the store to get food, an animal leaves its “shelter” to get the things they need to live. If the animal's needs aren't met, it will move to a different habitat.
Different animals need different habitats. A fish, for example, needs clean water in which to live. A grasshopper, however, needs a big space where it can hop and a variety of leaves that it can eat.
There are many plants and animals that will share the same habitat. A single animal or plant is an organism. All the organisms of one species living together in an area form a population. The populations that interact together in a habitat form a community. The community of living things interacts with the non-living world around it to form an ecosystem. All the ecosystems make up the biosphere, the area of life on Earth.
Because resources like water and food may be limited, plant and animal species often compete with each other for food and water. The only way that they can all live together is if they occupy slightly different niches or hold different “jobs” in the community. Many species may share a habitat, but no two species can occupy exactly the same niche. They all have their own specific jobs or niches in the community. The habitat is the physical space occupied by the plant or animals, while the niche is the role the plant or animal plays in the community found in the habitat.
For example, the habitat of a squirrel tends to be trees, or a forest. Its niche is to consume nuts and seeds, to spread and bury seeds which later germinate into new trees, and to be a food source for predators such as great horned owls.
There are lots of different habitat types on Earth. Habitat examples include lakes, streams, forests, deserts, grasslands, or even a drop of water. All habitats on the Earth are part of the biosphere. Because the Earth is always changing, habitats are constantly changing. Global habitats that have similar climates and plants are called biomes.
So what's a critical habitat?
When a species is threatened — that is, likely to become an endangered species within the foreseeable future — it becomes important to protect its habitat. Certain areas become a critical habitat, regions that are protected by law to prevent destroying, removing or bothering those species so that they can produce young and continue to thrive.
In 1975, the grizzly bears of Yellowstone National Park were listed as a “threatened species.” Wildlife biologists estimated there were just over 130 grizzlies remaining in the Yellowstone area. But through protection of their habitat and efforts to make sure that they could survive, their numbers have increased and their territory has expanded. Things are definitely looking up for the bears!