What is an endangered species? It is a kind of plant or animal at risk of going extinct. Species become endangered for two main reasons. First, their habitat may disappear. The second way is if their population is too small.
Loss Of Habitat
A loss of habitat can happen naturally. For example, dinosaurs lost their habitat about 65 million years ago. Scientists believe an asteroid hit the Earth. It blasted dust into the air. Less sunlight reached plants, so they died. The air grew cooler. These changes killed off the dinosaurs, experts think.
Today, humans cause a lot of habitat loss. They cut down forests. They turn fields into farms. These changes affect wild species that live there. It may destroy the foods some animals need. There may not be safe places to raise young. Without a healthy habitat, some plants and animals may become endangered.
Loss Of Genetic Variation
A population that is too small can also make a species endangered. How? Genetic variation. Genetic variations are small differences within a species. They help a species survive. Say one oak tree needs less water than another oak tree. If there is less rain, the first oak tree is more likely to live. It may give its genetic information to its seeds. Then that oak's seedlings may need less water, too.
The more genetic variation the better. It helps species survive habitat changes. It helps them survive diseases, too.
The Red List
One environmental group keeps a "Red List of Threatened Species." This list has seven levels. It tells which species are in the most trouble. Maybe the population is shrinking fast. Maybe its habitat is disappearing.
Here are the different levels.
Least Concern And Near Threatened
Least concern is one level. Species of least concern have little chance of dying out. This level includes people as well as dogs and cats.
A near threatened species is one that may be in trouble soon. For instance, some violets are near threatened. These flowers grow in Africa and South America. Their forest habitat is disappearing.
Vulnerable, Endangered And Critically Endangered
These three levels include species facing bigger trouble.
Vulnerable Species: Ethiopian Banana Frog
This small frog lives in Africa. Its forest habitat is being cut down.
Endangered Species: Siberian Sturgeon
The Siberian sturgeon is a large fish. It lives in rivers and lakes in Russia. Its population has fallen sharply. Too much fishing and pollution are mostly to blame.
Critically Endangered Species: Bolivian Chinchilla Rat
This rat lives in South America. Its habitat continues to shrink. The big threat is the loss of its forest habitat.
Extinct In The Wild And Extinct
A species is extinct in the wild when it can no longer live in its natural home. An animal may still live in zoos, though. Or a plant may grow with special care.
Extinct in the Wild: Black Soft-shell Turtle
This Asian turtle only lives in one small pond. It is located in Bangladesh. Humans feed and care for them.
A species goes extinct when the last of its kind dies.
Extinct: Cuban Macaw
The Cuban macaw was a tropical parrot. They lived on the island of Cuba. People hunted them and made them pets. The last one died about 150 years ago.
Protecting Endangered Species
Why is it important to know if a species is endangered? If people know, they can take action. They can pass laws to stop hunting. They may stop people from destroying important habitats. Some species have survived because humans helped.
The brown pelican is a good example. This seabird lives on the coasts of North and South America. In 1970, there were only 10,000 left. It was listed as vulnerable.
People took action. They raised baby pelicans and released them into the wild. They banned chemicals that harmed the birds. The number of brown pelicans climbed. Today, it is safe from extinction.