Assam: Rare Golden Tiger resurfaces in Kaziranga, unlocking genetic secrets
Guwahati: After a gap of almost three years, the rarest of the rare Bengal tiger morph (the golden morph) has surfaced again in Kaziranga National Park in Assam, bringing cheer and delight to all visitors and scientists alike.
The Adult male golden tiger was spotted by Gautam Narayanan who was visiting the Park and was ably guided by local tour guide Buddheshwar Konwar who spotted it at a distance, said a park official.
Diverse forms of pigmentation phenotypes are known in many species of birds, butterflies, wild ungulates, domesticated animals, and also in humans. Phenotypic variations are driven by evolutionary forces such as selection and random genetic drift.
Tigers have a unique striping pattern that is known to exist in several coat colour variants. The most famous being the pseudo-melanistic (or darker) morph that is found in the wild at Simlipal Tiger Reserve in Odisha.
The golden coloration of tigers is the result of a genetic mutation involving both point mutations and chromosomal abnormalities, said experts.
The white tiger pelage is a recessive trait and such individuals are now only confined to zoos. The golden phenotype (as demonstrated by the Kaziranga Tiger) is also a rare recessive trait and is currently being investigated through non-invasive scat sampling and DNA mapping by scientists Prof. Uma Ramakrishnan and her team at the National Centre for Biological Sciences.
As both pseudo-melanistic and golden phenotypes are expressed as recessive traits, their occurrence in the natural population suggests an even larger number of heterozygotes in the population, which can only be detected through genetic analyses (as the heterozygotes look the same as a normal tiger).
However, if such heterozygotes are present in numbers less than expected from theoretical values, it might suggest a lack of genetic connectivity.
In such a case, it might be critical to maintain habitat connectivity to sustain the natural variation and reduce the threat of extinction.