Recently, an important conservation effort unfolded when a tigress from the Tadoba-Andhari Tiger Reserve in Maharashtra was relocated to the Similipal Tiger Reserve in Odisha. This move aimed to enhance genetic diversity amidst rising concerns of inbreeding in the local tiger population, particularly concerning the unique pseudo-melanistic tigers. These tigers, characterised by their dark coats with faint orange stripes, have become a focal point of genetic research and conservation strategies.
About Pseudomelanism
Pseudomelanistic tigers are a rare colour variant of the Bengal tiger, resulting from a genetic mutation affecting their coat patterns. Unlike typical tigers, these individuals exhibit a darker appearance due to wider and more pronounced stripes. Historically, sightings of these tigers were deemed mythical until documented evidence emerged in the 18th century. The first known depiction was by British artist James Forbes, who illustrated a black tiger in his watercolour paintings.
Genetic Basis of Colouration
The striking appearance of pseudomelanistic tigers is attributed to a mutation in the Taqpep gene, which influences the distribution and width of stripes. This genetic alteration leads to a higher surface area of dark pigmentation, creating the illusion of a nearly black coat. Research indicates that this mutation is prevalent in the Similipal population, with a staggering 60% chance of tigers carrying the gene.
Population Dynamics and Inbreeding
The Similipal Tiger Reserve serves as a genetic enclave for these unique tigers. A recent study brought into light that of the 30 tigers estimated in Odisha, 27 reside in Similipal, with at least 13 identified as pseudo-melanistic. The isolation of this population has resulted in a genetic bottleneck, leading to increased inbreeding and the perpetuation of the Taqpep mutation. Genetic drift has further contributed to the high frequency of this trait, as random chance plays an important role in the survival of certain genetic variations.
Conservation Implications
The relocation of the tigress to Similipal is part of a broader strategy to mitigate the risks associated with inbreeding. By introducing new genetic material, conservationists hope to enhance the overall health and viability of the tiger population in Odisha. The presence of pseudo-melanistic tigers is not merely a curiosity; it puts stress on the importance of genetic diversity in maintaining resilient wildlife populations.
Global Context
While the phenomenon of pseudo-melanism is primarily observed in the Similipal reserve, other regions have reported sightings of unusual tiger colourations, albeit less frequently. Captive breeding programmes, such as those in Nandankanan Zoological Park and Arignar Anna Zoological Park, have also produced pseudo-melanistic tigers, tracing their lineage back to Similipal. This marks the need for global awareness and conservation efforts to protect the genetic integrity of tiger populations worldwide.
Questions for UPSC:
- Discuss the significance of genetic diversity in tiger conservation.
- Explain the role of the Taqpep gene in the colouration of tigers.
- What are the implications of inbreeding in isolated tiger populations?
- Assess the conservation strategies employed for the Similipal Tiger Reserve.
- How can the phenomenon of pseudomelanism inform broader wildlife conservation efforts?
