Context

According to a recent study, published in the latest edition of People and Nature by the British Ecological Society, the horns of rhinoceroses may have become smaller over time from the impact of hunting.

Key-highlights: 

• The study found that the rate of decline in horn length was highest in the critically-endangered Sumatran rhino and lowest in the white rhino of Africa, which is the most commonly found species both in the wild and in captivity. 
• Rhinos have long been hunted for their horns. 
• This observation follows patterns seen in other animals, such as tusk size in elephants and horn length in wild sheep, which have been driven down by directional selection due to trophy hunting.
• Reasons for shrinking Horns: Rhinos have long been hunted for their horns, which are highly valued in some cultures.

Rhinos in India:

• There are five species and 11 subspecies of rhino. White, Black, Indian, Javan, and Sumatranmake up the five species of rhino in the world. 
• The Indian rhino is the largest of the rhino species.
  • It is identified by a single black horn and a grey-brown hide with skin folds.
• Protection Status
  • IUCN Red List: Vulnerable
  • CITES: Appendix I
  • Wildlife Protection Act, 1972: Schedule I
• White and black rhinoceros are native to Africa.
• Indian, Javan and Sumatran can be found in India and Asia.

Conservation Efforts by India:

• New Delhi Declaration on Asian Rhinos 2019: Signed by India, Bhutan, Nepal, Indonesia and Malaysia.
• National Rhino Conservation Strategy 2019
• Project to create DNA profiles of all rhinos by the Ministry of Environment Forest and Climate Change (MoEFCC).
• Indian Rhino Vision 2020.
• World Rhino Day is celebrated on September 22 every year.