What are the factors that are endangering the balance of life? Scientists are predicting that half of all our plants and animals will be extinct by Here are the reasons;. Habitat destruction is the number one driver of species extinction. When we demolish a forest in a certain area, we have doomed all the living things thriving in that environment.
When we cut off rivers with dams or build roads through a forest, we are destroying ecosystems. Where will they live? Do we bother to relocate them? Is that even possible?
Maybe the big animals which we can see, yes. Deforestation has killed off more species than we can identify. To date, we have destroyed around 13 million hectares of forest, home to thousands of species big and small. We are destroying forests to supply the ever growing needs of our civilization for wood, paper, and other materials that come from our trees. Due to deforestation, we are driving the Mountain Gorillas away from their habitat and they are unable to handle the stress of having to cope.
Hunting and harvesting are necessary activities of humans. We need to eat and survive. If this were our only reasons, the planet can probably sustain us. It can reproduce and sustain us with a steady supply. The disappearance of species from Earth is ongoing, and rates have varied over time. To some extent, extinction is natural. Humans also cause other species to become extinct by hunting, overharvesting, introducing invasive species to the wild, polluting, and changing wetlands and forests to croplands and urban areas.
Even the rapid growth of the human population is causing extinction by ruining natural habitats. Passenger pigeons, billions of which frequently blanketed North American skies when Europeans arrived on the continent, went extinct when the last one died at the Cincinnati Zoo in Fossils show that there have been five previous periods of history when an unusually high number of extinctions occurred in what are known as mass extinctions.
Those losses, however, also paved the way for dinosaurs to evolve into existence, as mass extinctions create a chance for new species to emerge. Dinosaurs met their end about 65 million years ago in another mass extinction at the end of the Cretaceous period.
Scientists believe that volcanic eruptions in India caused global warming that also may have contributed to the mass extinction. Scientists are debating whether Earth is now in the midst of a sixth mass extinction. If so, it may be the fastest one ever with a rate of 1, to 10, times the baseline extinction rate of one to five species per year.
Humans are largely responsible for the striking trend. But not all species will be able to adapt quickly enough to stave off extinction and many are expected to perish.
In the past years, we know of approximately 1, species that have gone extinct, from the woodland bison of West Virginia and Arizona's Merriam's elk to the Rocky Mountain grasshopper, passenger pigeon and Puerto Rico's Culebra parrot — but this doesn't account for thousands of species that disappeared before scientists had a chance to describe them [ 4 ].
Nobody really knows how many species are in danger of becoming extinct. Noted conservation scientist David Wilcove estimates that there are 14, to 35, endangered species in the United States, which is 7 to 18 percent of U. The IUCN has assessed roughly 3 percent of described species and identified 16, species worldwide as being threatened with extinction, or roughly 38 percent of those assessed.
In its latest four-year endangered species assessment, the IUCN reports that the world won't meet a goal of reversing the extinction trend toward species depletion by [ 5 ]. What's clear is that many thousands of species are at risk of disappearing forever in the coming decades. Scientists estimate that a third or more of all the roughly 6, known species of amphibians are at risk of extinction [ 6 ].
Frogs, toads, and salamanders are disappearing because of habitat loss, water and air pollution, climate change, ultraviolet light exposure, introduced exotic species, and disease. Because of their sensitivity to environmental changes, vanishing amphibians should be viewed as the canary in the global coal mine, signaling subtle yet radical ecosystem changes that could ultimately claim many other species, including humans.
BIRDS Birds occur in nearly every habitat on the planet and are often the most visible and familiar wildlife to people across the globe. As such, they provide an important bellwether for tracking changes to the biosphere. Declining bird populations across most to all habitats confirm that profound changes are occurring on our planet in response to human activities. A report on the state of birds in the United States found that 31 percent of the species in the country are of conservation concern [ 7 ].
Habitat loss and degradation have caused most of the bird declines, but the impacts of invasive species and capture by collectors play a big role, too. FISH Increasing demand for water, the damming of rivers throughout the world, the dumping and accumulation of various pollutants, and invasive species make aquatic ecosystems some of the most threatened on the planet; thus, it's not surprising that there are many fish species that are endangered in both freshwater and marine habitats.
The American Fisheries Society identified species of freshwater or anadromous fish in North America as being imperiled, amounting to 39 percent of all such fish on the continent [ 8 ]. In North American marine waters, at least 82 fish species are imperiled. Newer species that could survive in a warmer environment took their places.
People can also cause the extinction of plants and animals. The main reason that many species are endangered or threatened today is because people have. A habitat includes not only the other plants and animals in an area, but all of the things needed for the species' survival -- from sunlight and wind to food and shelter.
The United States has many habitats, from ocean beaches to mountain tops. Every species requires a certain habitat in order to live. A cactus, for example, needs the sunny, dry desert in order to grow. A polar bear, on the other hand, would not live in a desert, because it could not find enough food and water.
Pollution can also affect wildlife and contribute to extinction. The Nashville crayfish is endangered mainly because the creek where it lives has been polluted by people.
Pesticides and other chemicals can poison plants and animals if they are not used correctly. The bald eagle is one bird that was harmed by pesticides. In the past, a pesticide called DDT was used by many farmers. Rains washed the pesticide into the lakes and streams where it poisoned fish. After eating the poisoned fish, the eagles would lay eggs with very thin shells. These eggs were usually crushed before they could hatch.
Today, people are not allowed to use DDT, and this has contributed to the bald eagle being removed from the endangered and threatened species lists needed for the species' survival -- from sunlight and wind to food and shelter.
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