TIGER WITHOUT STRIPES

Black tigers were known in forests of Simlipal, Odisha, India since 1975-76. The subject came to acquire a scientific foothold when a melanistic tiger got killed (in self defense) in July 1993. Born Black makes a strong case for further research on colour aberrations in tigers and their implications for tiger conservation efforts in the country. The increased segregation of melanistics in a population is an indication of the beginning of an end to the natural sustenance of that majestic Royal Bengal Tiger in tawny and black stripes. It is a matter of concern warranting a fresh look at the approach to tiger conservation. A range of twelve types of body colouration from stripeless-white tiger, white tiger, golden tiger, normal light yellow tiger, normal deep yellow tiger, rufous tiger, brown tiger, melanistic tiger, blue tiger and black tiger have been discussed with a hypothetical normal distribution curve. With increasing human pressure on tiger habitats and increased emergence of a phenomenon where tiger populations are getting restricted like insular fauna, the chances of inbreeding are certainly increasing. The natural conclusion which, therefore, emerges is that in future, wherever colour aberrations are appearing in a cat species, if chances of inbreeding are greater because of small or isolated populations, the aberrations will gradually get segregated and incidence of individuals with colour aberration shall be more frequent. The concept of forest corridors, specially conceived for elephant management, could additionally ensure the exchange of genes from adjacent areas so that homozygous conditions of pure black, melanistic or white are reduced in nature and the majestic tiger in tawny and black continues to reign in the forest habitat. Conservation of tiger requires aiming at reducing the possibility of genetic erosion of normal colouration of the tiger in the wild through habitat improvement.

Data collected from pugmark tracking over four years from 1989 to 1992 were combined and analysed for biological inferences. Results were kept very simple and intelligible to all staff who participated in the exercises. During the period 1989-1992 the tiger population appeared stable around 94 including male, female and cub. The mean male:female ratio was 1:2 for tiger and 1.8 for leopard. The tiger cubs at 10.0-10.9cm PML (hind Pug Mark Length) were low in numbers, suggesting their disappearance from the main population. This size corresponds to stage of separation from mother and entering a wandering phase before creating own territory. Because of track overlaps usually single cubs could be identified with the mother tigress, and 36% of total numbers of females held all cubs in three age-classes. It appeared that about 12% of the female population litter in a season. About 72% of the total cub-holding-mothers were within 12.0-13.9cm PML. There is scope to refine the census technique for Similipal Tiger Reserve to account for all the cubs with their mothers.

Abstract in: International Symposium on the Tiger, Delhi., Ministry of Env. & Forests, February 1993., 1993

Data collected from pugmark tracking over four years from 1989 to 1992 were combined and analysed for biological inferences. Results were kept very simple and intelligible to all staff who participated in the exercises. During the period 1989-1992 the tiger population appeared stable around 94 including male, female and cub. The mean male: female ratio was 1:2 for tiger and 1.8 for leopard. The tiger cubs at 10.0-10.9cm PML (hind Pug Mark Length) were low in numbers, suggesting their disappearance from the main population. This size corresponds to stage of separation from mother and entering a wandering phase before creating own territory. Because of track overlaps usually single cubs could be identified with the mother tigress, and 36% of total numbers of females held all cubs in three age-classes. It appeared that about 12% of the female population litter in a season. About 72% of the total cub-holding-mothers were within 12.0-13.9cm PML. There is scope to refine the census technique for Similipal Tiger Reserve to account for all the cubs with their mothers.

Mammalia, 2010

Science China Life Sciences, 2014

… Biology-Zeitschrift fur …, 2010

We analyzed mtDNA polymorphisms (a total of 741 bp from a part of conserved control region, ND5, ND2, Cyt b and 12S) in 91 scats and 12 tissue samples of Bengal tiger (Panthera tigris tigris) populations across Terai Arc Landscape (TAL) located at the foothills of Himalayas in North Western India, Buxa Tiger Reserve (BTR), and North East India. In TAL and BTR, we found a specific haplotype at high frequency, which was absent elsewhere, indicating a genetically distinct population in these regions. Within the TAL region, there is some evidence for genetic isolation of the tiger populations west of river Ganges, i.e., in the western part of Rajaji National Park (RNP). Although the river itself might not constitute a significant barrier for tigers, recent human-induced changes in habitat and degradation of the Motichur-Chilla Corridor connecting the two sides of the tiger habitat of RNP might effectively prevent genetic exchange. A cohesive population is observed for the rest of the TAL. Even the more eastern BTR belongs genetically to this unit, despite the present lack of a migration corridor between BTR and TAL. In spite of a close geographic proximity, Chitwan (Nepal) constitutes a tiger population genetically different from TAL. Moreover, it is observed that the North East India tiger populations are genetically different from TAL and BTR, as well as from the other Bengal tiger populations in India.

PLoS Biology, 2004

Eight traditional subspecies of tiger (Panthera tigris), of which three recently became extinct, are commonly recognized on the basis of geographic isolation and morphological characteristics. To investigate the species' evolutionary history and to establish objective ...