Golden ,Black Or White , Colourful Tigers are Cause of Concern

 

Tyger Tyger, burning bright, 

In the forests of the night

William Blake, one of the celebrated English poets of 18th century, may have not written this poem had he seen the black tigers of Simlipal tiger reserve of Odisha. Blake’s source of inspiration, literary critics have written, was the flame-like appearance of a tiger’s stripes. But Simlipal tigers have dominant black stripes and have been in news again after camera traps captured its images in Odisha jungles in the last week of July. A black tiger was spotted marking its territory on a tree trunk at Similipal tiger reserve (STR) in the Mayurbhanj district of Odisha. Earlier, this year, we had visuals of a golden tiger coming from  Kazirangana national park of Assam. We already have white tigers and the first such animal was spotted in Rewa district of Madhya Pradesh in 1951. Actually, we can have as many as 14 types of colouration patterns in tigers including the one that was “ burning bright”  in Blake’s  “The Tyger” published in 1794. 

Black Tiger Family Of Simlipal 

But first more about the black tigers: The first black tiger sighting was believed to have been reported from the STR in 1970. Again in 1991, a forest guard in the upper Barakhamba Range of STR sighted “a family of black tigers”. In the absence of any visuals both these sightings were dismissed as a case of mistaken identity.  Remember, there was no of camera trap then. “The subject acquired a scientific foothold only in July 1993, when a melanistic tigress was killed by a tribal youth in Podagada village, near Similipal,” L.A.K. Singh former research officer at STR was quoted in media. But camera traps revealed the secret in 2007 when researchers from the Wildlife Institute of India, Dehradun, captured pictures of three black tigers also termed as melanistic tigers. “Later as many 170 pairs of cameras were installed in STR in 2012-2013, which had been recording interesting findings”, officials recalled. Since then black tiger images keep coming out.

Also read: Rising Tiger Numbers Midst Shrinking Forest Cover Makes No Sense

 In 2015, a normal tigress was found with a melanistic cub, while in 2016, a melanistic tigress was photographed with her three cubs, two of which were black. According to L.A.K. Singh, people believe that Similipal is the only forest in India which has an established presence of melanistic tigers; this belief is not entirely true. “Few know that in March 1997, a melanistic tiger was also sighted in Satkosia Gorge Sanctuary (part of Satkosia Tiger Reserve) in Odisha. “What is even more unusual is that neither are their ( black tiger )activities and behavioural traits different from the usual tigers nor do they face problems of acceptance within the tiger community, ”former honorary wildlife warden of STR, Bhanumitra Acharya said. Black tigers can also be found at the Nandankanan Zoo, Bhubaneswar, where they are caged and are healthy. In all these cases, several areas of the tigers’ coats were abnormally dark or black, and such tigers were termed pseudomelanistic  (pseudo  meaning false; melanistic  is  dark/black coloured).

Inbreeding leads to Black Colour, Cause of Concern 

Wildlife tourists may enjoy sighting of colourful tigers, they have been a cause of major concern for conservationists. A paper published in September 2021 in the National Centre for Biological Sciences (NCBS ) of Tata Institute of Fundamental Research (TIFR)  revealed the scientific reasons  of  “ What makes black tigers  of Simlipal black” Research conducted by a team of NCBS  “discovered the genetic cause of the odd coat colouration and patterning in Similipal’s black tigers”. Headed by Uma Ramakrishnan and her student Vinay Sagar NCBS, Bangalore, the team have found that “ a single mutation in the gene Transmembrane Aminopeptidase Q (Taqpep) causes the black tigers to develop stripes that seem to have broadened or spread into the tawny background.”  

Also read: Golden Tiger And  Its Gloomy Roar In Kaziranga National Park  

Raising an alarm, the findings said, “ Genetic analyses of other tiger populations from India and computer simulations suggest that the Similipal black tigers may have arisen from a very small founding population of tigers and are inbred. Similipal tigers are an isolated population in eastern India and gene flow between them and other tiger populations is very restricted. This has important implications for tiger conservation as such isolated and inbred populations are prone to extinction over even short periods of time.” While colour aberration of tigers may be a tourist attraction,  it is a cause of concern and does not augur well in terms of their biological or conservation implications in the wild, said  LAK Singh . “More aberrations in nature mean all is not well with the natural gene pool, making it necessary to have increased tiger corridors to reduce genetic depression,” he says.

Jungle Bottlenecks and Black Tigers 

The important connectivity  with STR are patches of forests  connecting  the tiger reserve with  Badampahar reserve forest in the west,  Kuldiha sanctuary in  the south eastern side  and upto Atai  reserve forest  in Keonjhar district  in the south western side.  In 20010, the National Tiger Conservation Authority (NTCA) identified   a potential connectivity between STR and Satkosia tiger reserve .  It is a very long corridor, but is highly fragmented due to intense mining activities, power stations and a large number of human habitations. According to a study by the Wildlife Institute of India, conducted in 2014, there are more than 250 villages in and around  this corridor. Simlipal is subjected to high anthropogenic pressure  due to presence of 68 villages  with the reserve  and  about 1200 villages in the periphery . The local people still follow a unique tradition of  ritual mass hunting  called Akhand Shikar. Control on this practice is a major challenge. 

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For Satkosia Tiger Reserve, Similipal is considered to be the source population of tigers because of seclusion of Satkosia from other connected protected areas. Conservationists hope that the proposed corridor will help recover tiger populations in the Satkosia Tiger Reserve in the near future.  At present, tiger densities in both Similipal and Satkosia are depressed and there is a lack of a source population to ensure tiger occupancy within the larger landscape. With appropriate protection and managerial changes, tiger populations in both these reserves can revive, but their long-term survival would depend on the gene flow between these populations.  Tigers resort to inbreeding when their population is almost islanded without connectivity to other landscapes, which is mainly caused by habitat loss and destruction of corridors. A joint study by the National Centre for Biological Sciences and Cardiff University had flagged the concern that Indian tigers no longer possess 93% of their genetic variation. 

Black, White, Blue And Ten More Colours

Repeated sightings of the golden and black tigers have come at a critical time when India’s Tiger Census entered the Guinness World Records for being the world’s biggest wildlife survey. India awaits the tiger census results hoping to double the population of the big cat. Simultaneously there is a growing concern over key tiger corridors facing a threat from a variety of reasons including population pressure, infrastructure building, floods and coal mines. 

Also read:  Tiger Corridor : Now Satpuda Melghat National Parks Connectivity At Risk 

L.A.K. Singh has expressed  the  probability of “at least fourteen known types of body coloration in tigers” in his book “Born Black : The Melanistic Tiger in India” in 2002. They  include  (1) Stripeless White Tiger (2) Tigers with reduced stripe on white background ( 3) 'Lighter' WhiteTigers  (4) 'Darker'White Tigers  (5) Golden (Pallid) ( 6) Normal (light yellow)  (7) Normal (8) Normal (deep  yellow)  (9) Rufous  (10) Brown with dark stripes  (11) Brown without stripes  (12) Melanistic  (13) Blue  (14) Black .The appearance of tigers with aberrant  coloration can be expected as a regular  occurrence in some places but overall an extremely rare natural phenomenon. 

Cover Image from Nandankana Zoological Park, other Images from Simlipal Tiger Reserve Camera Traps  and Satya Swagat from Nandankanan Zoological Park