Reasons for Animal Extinction
Animals form an integral part of the nature's ecosystem. Nature has blessed all to thrive and prosper. But, man being the intelligent of them all took undue advantage to race ahead, and thrust his supremacy over others. Rapid expansion of human population combined with the need for growth has created a situation even beyond the control of human beings.
Deforestation and encroachment of lands have led to habitat loss for many animals. It is the most important reason for animal extinction. Tropical Rainforests are inhabited by a large number of animals. Huge demand for forest resources has led to the establishment a large-scale lumbering industry. Clearing of tropical forests for timber resources, for extraction of petroleum and mineral resources, for cash-crop plantations, and subsistence farming has destroyed the natural habitats of native animals.
Habitat loss reduces the health of the ecosystem, and causes a decline in the numbers of the native species. It is believed that elimination of 90 percent of habitats will lead to the reduction in the number of species by 50 percent.
Moreover, adaptability in new environment is difficult for the relocated species. They become susceptible to demographic problems and environmental changes. Some catastrophic events and genetic disorders add to their problems.
Poaching and wildlife trade in animals and their body-parts have become a reason for extinction of many animals. Tiger bones and horns of rhinoceros are believed to possess healing properties, which are widely used in making traditional medicines in China. Elephants across the world are hunted for their ivory-tusks, which are in great demand in the international market. Animals in Africa are killed for bush meat (consumption of meat of wild animals) trade whereas several animals are captured to be kept as pet.
Furthermore, fur trade was very popular in Europe and the United States in the 1950s and 1960s. Heavy demand in fur-products led to the killing of animals on a large-scale for their pelts. It is estimated that, in late 1960s, pelts of more than 10,000 Leopards, 3,000 Cheetahs, 15,000 Jaguars, and 200,000 Ocelots were being imported legally in the United States and Europe every year.
Biomedical research has also promoted trade in animals. Animal testing has created a demand for them, which are brought by the biomedical research companies for executing their further research on drugs.
Climatic changes have immensely affected the living beings. Global warming caused due emission of greenhouse gases and depletion of ozone layer has threatened the existence of one and all. Frogs are considered to be a vulnerable species due to global warming. The disappearance of Golden toad in Costa Rica is a classic example of animals threatened with climatic changes.
In addition to the factors mentioned above, introduction of non-native species into the new habitats have threatened the existence of native species. The introduction of goats and other non-native animals in the Galapagos Islands endangered the Galapagos tortoise. The goats fed upon the tortoises' food supply, and the tortoise eggs were eaten by the newly introduced pigs, dogs, and rats.
Therefore, the endemic species of animals have become vulnerable to habitat loss caused by human factors.