Extinction occurs when species are reduced or terminated because of environmental forces.
Explanation:
(a) habitat loss and degradation occurs when a habitat is destroyed by human activities which makes fewer species to leave there, often leading to the extinction.
For example, birds such as parrots have faced with extinction due to deforestation in the south and central American rainforest.
(b) habitat fragmentation occurs when large area of habitat is reduced in size and divided into two or more fragments, which reduces the ability of species to move across their habitat.
Habitat loss differs from habitat fragmentation sin habitat loss only refers to decrease in the size of the natural habitat, while fragmentation is the breaking apart of habitat.
For example, new roads and housing development may block the movement of small animals, expose large animals to hunting and poaching eg Elephants
c) introduction of non-native species may lead to taking over resources of other species such as sunlight, water, food and space causing more damage.
For example, the tamarisk plant has affected the survival of other species by sucking over 800 billion gallons of water in the Arkansas river in the United States.
d) accidentally introduced non-native species of course when they are transported into areas which they are not considered natives which may result in the extinction of other species. for example the africanized honey bees which were unintentionally introduced are much more defensive and resulted in the death of several horses and other animals.
e) commercial coaching and illegal hunting involves capturing of wild animals for trade. Elephants are victims of illegal hunting and poaching.
(f) predator and pest control pose a serious negative impact on the environment because they may lead to the destruction of biodiversity.
For example, birds and other aquatic organisms and animals are under the threat of harmful pesticides for their survival.
(g) legal and illegal trade of exotic pets has resulted in the successful establishment of non‐native species which may lead to over taking of resources for native species. For example powder blue surgeonfish are usually exported because of their demand.
(h) climate change and pollution has affected thousands of species. As Sea levels are rising and oceans are becoming warmer it is affecting turtle nesting sites. It alters sand temperatures, which then affects the sex of hatchlings, which may lead to their extinction.
