Causes of animal extinction
Animal extinction is happening nowadays due to the multiple factors of environmental degradation. The primary cause of environmental degradation is human disturbance. Extinctions caused by human are generally considered to be are recent phenomena. When humans convert wild areas for agriculture, forestry, urban development, or water projects including dams, hydropower, and irrigation, they reduce or eliminate its usefulness as a habitat for the other species that live there. The temperature of the environmental impact varies with the cause, the habitat, the plants and animals that inhabit it.
Fragmentation of habitat carries long term environmental impacts, some of which can destroy entire ecosystem. Habitat loss poses the greatest threat to species. Some wildlife species require large land in order to meet all of their needs for food, habitat, and other resources. These animals are called area sensitive. When the environment is fragmented, the large patches of habitat no longer exist. It becomes more difficult for the wildlife to get the resources to survive. A more critical result of habitat fragmentation is land disturbance. On the other hand, natural disaster is also one of the courses of animal extinction.
Mother Nature causes environmental problems too. Things like landslides, earthquakes, tsunamis, hurricanes, and wildfires can completely decimate local plant and animal communities to the point where they can no longer function. This can either come about through physical destruction via natural disasters or by the long-term degradation of resources by the introduction of an invasive alien species to a new habitat. The latter often occurs after hurricanes, when lizards and insects are washed across small stretches of water to foreign environments.
Sometimes, the environment cannot keep up with the new species, and degradation can occur. Acid rain is also normally occurs when sulphur dioxide from coal plant emission combines with moisture present in the air. A chemical reaction creates the acid rain. Acid rain can be acidity and pollute lakes and streams. According to the U. S. Environmental Protection Agency (EPA), if enough acid rain falls in a given environment, it can acidify the water or soil to a point where no life can be sustained. Plants die off. The animals that depend upon them disappear. The condition of the environment deteriorates.
The third major reason of endangerment and extinction is poaching and commercial hunting. A poacher is someone who hunts and kills rare animals for profit. Often times an animal is killed in such a vicious way that it not only cruel but inhumane as well. Poachers do not hunt for food or for legal side game hunting. They will kill and decimation often times for one small part of the animal that they can sell on the Black Market. Elephants are hunted solely for their tusks which are made out of ivory, an extremely valuable material that is often used to make several different kinds of art or jewelry.
Tigers, leopards, cheetahs and jaguars are hunted for their fur hides which can be made into all kinds of clothing. Lastly, rhinos are hunted and killed for their horns which are believed by some to contain magical powers and spirits. Some of the time, rare animals are trapped and exported to private zoos or laboratories, which is just as serious of a crime. Although most countries have strict rules and regulations about the hunting and transporting of these animals, it seems that a few are always getting around these laws or getting away with their crimes.
Commercial hunting is most popularly known by dolphin hunting in Japan. They hunt dolphins for food and the profits from dolphin as showcase ventures. They not even realize that dolphins are sensitive to sound pressure, so dolphin will suicide when they are suffering. Although many countries such as the US and Canada are now leading the way to ban all such whale hunting, many other countries such as Japan, Norway, Sweden, and Finland continue to hunt these whales . Laws and regulations have been raised to stop this hunting within 200 nautical miles of many countries.
The sea still remains free though to any and all hunting that can be done. Pollution is the introduction of potentially harmful chemical or physical constituents into the environment, which substances that can cause animal extinction. Chemical pollutants such as sulfur dioxide, carbon monoxide, and oxides of nitrogen are causing functional impairment or death of organisms. In recent times humans have spread thousands of synthetic chemicals into the environment and altered the distribution of many naturally occurring substances which leads to conditions that wildlife species had never experienced before.
In many instances these new conditions have disrupted the delicate biological machinery evolved by organisms over thousands of years. Besides that, the use of synthetic chemicals to control pests, principally insects, weeds, and fungi, became an integral part of agriculture and disease control after World War II. These chemicals were credited with providing an inexpensive means of increasing crop production, preventing spoilage of stored foods, and saving many millions of human lives by the prevention of certain insect-borne diseases.
When birds and mammals become coated with oil, the insulating property of their feathers or fur is lost. Feathers and fur provide insulation by trapping a layer of air between the skin and the external environment. Oiling disrupts the arrangement of feathers and hair that retains this insulating layer. In arctic environments, the resulting hypothermia contributes to the death of many animals. According to the statistic a total of 36,466 dead seabirds, 1,015 dead sea otters, and 144 dead bald eagles were recovered from the spill area.
For several reasons these statistics are not indicative of the total numbers of animals that died. Many of the 1400 miles of affected shoreline consist of inaccessible or poorly mapped areas that could not be investigated. Furthermore, many animals that were killed were never recovered. Some species, such as harbor seals, sink when they die and therefore are not represented at all in the mortality counts. Actual mortality of oiled birds probably exceeded 100,000, the highest losses of birds recorded for any oil spill (Heneman 1989).