�Inbreeding, habitat loss may have led to colour aberrations in KNP tigers�
KAZIRANGA, July 17 - Skin colour variation among Royal Bengal Tigers have been noticed in the Kaziranga National Park-cum-Tiger Reserve as four such tigers were seen roaming there recently.
According to an official report released by the Kaziranga National Park authority, colour variation among Royal Bengal Tigers is quite rare given the genetical setup of the big cat species.
The skin colour of this species is generally yellowish with black stripes in between while the abdominal part is white. The yellowish colour is controlled by a set of �agouti genes and its alleless and black coloured stripes are controlled by a set of tabby genes and its alleles�. Any suppression of these genes or any mutation may lead to variation of colours in the big cat species including that of Royal Bengal Tigers.
The report further says that �agouti gene interacts with some pigment cells to form yellow to brown or even red to black expressions. This kind of interaction may lead to dark or light bands of hairs in the animals.�
Many types of colour variations might occur among tiger species either in zoos or in the wild. Therefore, it is entirely possible that some tigers may have stripes, others may be stripeless or even have reduced or light stripes or some tigers may even be brownish without stripes.
Experts in the report said that this colour aberration or variation among the Royal Bengal Tigers may be due to excessive inbreeding or destruction of suitable habitats.
According to a forest official, an ideal habitat forms an important component for any source breeding of the Royal Bengal Tiger. Kaziranga is considered as an ideal habitat for the Royal Bengal Tiger.
Loss of connectivity among the tiger habitats is another factor which may lead to colour variations.
Under normal circumstances, a dominant gene or trait or character is generally passed on to the next offspring in all kinds of mammals, whether animals or humans, said the official. He added that due to excessive inbreeding, the recessive trait or character which normally does not get expressed shows up or is expressed, leading to some variation or aberration in colour in some Royal Bengal Tigers in the Kaziranga National Park-cum-Tiger Reserve.
A recent study by the Cardiff University and the National Centre for Biological Sciences said that 93% of tiger DNA variants from the British era are no longer present in the current population of tigers. This cannot be termed as healthy but can serve as a caution for all of us to find ways for ensuring better connectivity among the fragmented tiger population remaining in many forest areas so as to prevent inbreeding. Inbreeding can cause many health conditions too.
So, definitely Kaziranga needs better connectivity among the different adjoining forest areas including those located at the foothills of Karbi Anglong on the southern side of the Kaziranga Tiger Reserve.
