Question

One of the chief reasons among the following for the depletion in the number of species making it endangered is.
A. Greenhouse effect
B. Habitat destruction
C. Over-hunting and poaching
D. Competition and predation

Answer 1

Hint: An endangered species is one that is on verge of extinction
The 4 main threats to biodiversity or sometimes we say evil quartet-
-Habitat loss and fragmentation
-Over-exploitation: Stellar’s cow and the passenger pigeon
-Alien species invasion: Nile perch and water hyacinth lead to the extinction of many marine creatures.
-Co-extinction: the extinction of one species leads to the extinction of another species as they were ecologically dependent on each other.

Complete answer:
-Greenhouse: It does affect the various species as it increases the general temperature of the earth. Due to this their life cycle and hibernation time period changes. Species living in extremely cold climates are facing problems due to this.
-Habitat destruction: this is the most important factor leading to the mass extinction as species are not getting anywhere to live their ecological interaction is lost. Tropical rainforest species are the most affected habitat. The species loss is huge. Therefore it is a basic drive to extinction.
-Overhunting and poaching: it does pose a great threat to the species. Species are being overexploited for commercial products and species were extinct due to this. but it possesses less threat in comparison to habitat loss.
-Competition and predation: If any foreign species are introduced, it leads to the invasion. But it does not possess any great threat to species diversity. If predators are too efficient it leads to the extinction of the prey species. But if the predator population is absent or less efficient it leads to the extinction of the prey population.

Hence, the correct answer is option (B).

Note: -Normally predators keep checking on the prey population. They maintain species diversity among prey by reducing the competition among prey for resources. If the predator population is removed from the habitat it leads to interspecific competition and species get extinct due to interspecific competition.

-Habitats by pollution also threaten the survival of many species. When large habitats are broken up into small fragments due to various human activities, mammals and birds require large territories, and certain animals with migratory habits are badly affected, leading to population declines.