Black Tigers

Subject – Environment

Context – NCBS study of ‘black tigers’ has shed light on genetic mystery.

Concept –

Black tigers — the tigers whose stripes are almost fused together in patches threatening to obliterate parts of their burnished orange coats.
An estimated 37% of Panthera tigris in the Similipal Tiger Reserve (in eastern India) are pseudomelanistic, characterised by wide, merged stripes.
This is the result of a rare mutation in one gene, Transmembrane Aminopeptidase Q or Taqpep, recessively inherited variants of which are responsible for the marks in domestic cats and king cheetahs.
The mutation is rarely seen in tigers outside Similipal.
Two factors are probably driving this change in appearance caused by the rare Taqpep p.H454Y: a founder bottleneck effect when a small subset of a large population, in this case tigers, establishes a new population, and the resulting genetic drift, where chance, more than natural selection, changes how common or rare genetic variants are.
With shrinking habitats, the tiger population becomes increasingly isolated. This causes inbreeding, resulting in a lack of genetic variation, making them prone to extinction.

Simplipal Tiger Reserve

Similipal National Park is a national park and a tiger reserve in the Mayurbhanj district in the Indian state of Odisha covering 2,750 km2 (1,060 sq mi).
It is part of the Mayurbhanj Elephant Reserve, which includes three protected areas — Similipal Tiger Reserve, Hadgarh Wildlife Sanctuary and Kuldiha Wildlife Sanctuary.
Simlipal National Park derives its name from the abundance of red silk cotton trees growing in the area.
The park is home to Bengal tiger, Asian elephant, gaur, and chausingha.
This protected area is part of the UNESCO World Network of Biosphere Reserves since 2009.
Simlipal Elephant Reserve is an ecosystem complete with forest vegetation (mainly sal trees), fauna and the adjoining Ho / Santhal tribal settlements.
Two tribes, the ErengaKharias and the Mankirdias, inhabit the reserve’s forests and practise traditional agricultural activities (the collection of seeds and timber).