Why Do Species Become Endangered?

Everyday between 50 and 150 plant and animal species become extinct. When you ask yourself “Why?” just think HIPPO.

   H abitat loss
         I ntroduced Species
                 P ollution
                          P opulation
                                   O ver-consumption

H abitat loss
Habitat refers to the place where an animal or plant species lives. This habitat consists of five elements: food, water, shelter, space and an appropriate mixture of these elements. All species must have adequate habitat in order to survive.
  • Habitat is the number one reason species become endangered.
  • Today, nearly every type of habitat is impacted by changes in land use and habitat loss.


  • In the United States, over half of our native prairies have been lost.
  • Grasslands have been cleared for agriculture and to make room for towns and cities.

  • Approximately 1 acre of rainforest is destroyed every second which equals 50 football fields every minute.
  • Destruction and severe damage is caused by logging, clearing for farming and cattle ranching, mining, dams and oil development.
Deciduous forests
  • Thousands of acres of deciduous forests have been destroyed throughout the world.
  • Deciduous forests are cleared for logging and to make room for expanding cities and towns.

  • Deserts are not vast empty spaces, but are delicate ecosystems teeming with life.
  • Deserts are destroyed or damaged by overgrazing by livestock, off-road vehicles, military equipment, mining and irrigation.
  • Each year between 300,000 and 500,000 acres of mangroves, salt marshes, freshwater marshes, bogs and swamps are destroyed.
  • Wetlands are drained for agriculture, development, industry and marinas.
I ntroduced Species
When non-native plants or animals are introduced into an area, they may disturb the natural balance of the ecosystem. Introduced species may over populate an area, compete for food, carry diseases for which native species may have no immunity, drive out other species and cause numerous other problems. They may prey on native species that have no defenses again the invader.

Animals and plants on islands seem to be particularly susceptible to destruction by introduced species. Hawaii has the greatest number of endangered species of any of the 50 states due to destruction of native species by introduced species.

P ollution
Pollution from pesticides, burning coal, oil and gas, industrial plants and automobile emissions all impact wildlife populations.
  • The Bald Eagle, our national symbol, is just one example of how pollution can cause a decline in wildlife populations. Bald Eagles became endangered largely due to the pesticide DDT. The pesticide caused the eagles and may other birds to lay thin-shelled eggs that could not survive. This pesticide is now banned in the United States.
  • Deformed frogs are being discovered around the world. Scientists have several theories to explain the malformations and declines in frog populations, including one implicating pollution. Damage to the earth’s ozone layer allows increased amounts of ultraviolet radiation to enter the earth’s atmosphere. Scientists fear that the additional UV light could be damaging not only to frogs but to humans as well.
P opulation
It took the entire history of humankind for the population to reach 1 billion around 1810. By 1930, this doubled to 2 billion people. Today there are over 6 billion people.
  • As the population continues to grow so does the need for space for housing and food.
  • Wild animals in the United States which were formerly isolated from the public, now must cross paths with humans who have moved into their former territories.

O ver-consumption
Because of over-consumption of the earth's resources, the world is losing wild places and species as the demand for food, minerals, lumber, and other resources increase.
  • Many species of animals, such as rhinos, tigers and bears, are endangered due to illegal hunting for their body parts. Animals are poached (hunted and killed illegally) and their body parts sold on the black market.
  • Some sources say that this black market is larger than illegal arms sales and second only to the drug black market.


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