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Which group of vertebrates comprises the highest number of endangered species?
A. Mammals
B. Fishes
C. Reptiles
D. Birds

Answer Verified Verified
Hint: They comprise of warm blooded vertebrate animals with mammary glands. Most of the animals have hair covering the skin.

Complete Answer:
- Vertebrates are the group of animals with backbone. They are of the subphylum Vertebrata, the predominant subphylum of the phylum Chordata. The vertebrates are also characterised by a muscular system consisting mainly of bilateral paired masses and a central nervous system that is partly confined within the backbone.
A species is said to be endangered when it is threatened by extinction. Species become endangered for two main reasons: loss of habitat and loss of genetic variation.

1) As of September 2016, 474 mammalian species are listed by the International Union for Conservation of Nature as endangered. A total of 8.6 per cent of all mammalian species assessed are listed as endangered.
2) As for fish, the International Union for the Conservation of Nature (IUCN) has listed 643 species as endangered as of September 2016. A total of 4.2 per cent of all species evaluated are listed as endangered.
3) In the reptilian group, as of September 2016, 382 endangered reptile species are listed by the International Union for Conservation of Nature (IUCN).The total of all evaluated reptile species listed as endangered is 7.4%.
4) As of December 2019, 461 species of birds are listed as endangered by the International Union for Conservation of Nature (IUCN). A total of 4.1% of all evaluated bird species are listed as endangered.

Therefore, the correct answer is option A. i.e., Mammals.

Note:
- Nearly 700 species have become extinct in recent times and more than 15,500 species (of which more than 650 are from India) currently face the threat of extinction.
- Habitat loss and fragmentation, biological invasions, over-exploitation, and co-extinction are some of the causes for the high rates of extinction in the present times.