Relevance: GS-3: Conservation, environmental pollution and degradation, environmental impact assessment

Key Phrases: Peak Density of Tiger Population, Carrying Capacity, Sunderbans, Wildlife Institute of India, Tiger Census.

Why in News ?

• Recently, the Wildlife Institute of India has told the state forest department in its preliminary report that the Sunderbans in West Bengal has more tigers than the mangrove delta can carry.
• Density of tigers in the Sunderbans may have reached the carrying capacity of the mangrove forests, leading to frequent dispersals and a surge in human-wildlife conflict.

Key Highlights

• In the 2014 national census, 76 tigers were traced in the zone.
• In 2018, the number of big cats was 88.
• The 2020-2021 Census conducted by the state forest department had found 96 tigers in the delta.
• The increase in the number of tigers could arguably be one major reason for the rise in straying incidents.
• The report suggests that when there are too many tigers in a particular forest, the “young adults” might be compelled to move out in search of new territory.
• As per the WII report the carrying capacity in sunderbans is three to five tigers per 100 sq km and in multiple blocks the density is more than that.

Parameters Affecting Peak Density of Tiger Population

The peak density of tiger population depends on several parameters like prey base, human interference, and male-female ratio of the tigers.

• Prey, eat, breed
  • Availability of food and space is the primary factor that determines how many tigers a forest can hold. And often, food is space for the tiger.
  • While they are known to establish vast ranges — the male in particular strives to control multiple females with typically smaller ranges — how far a tiger will range is determined by the abundance of prey in its forest.
  • In the Terai and Shivalik hills habitat — think Corbett tiger reserve, for example — 10-16 tigers can survive in 100 sq km.
  • This slides to 7-11 tigers per 100 sq km in the reserves of north-central Western Ghats such as Bandipur.
  • 6-10 tigers per 100 sq km in the dry deciduous forests, such as Kanha, of central India.
  • The correlation between prey availability and tiger density is fairly established.
  • As per the All-India Tiger report 2018 , the carrying capacity in the Sunderbans “at around 4 tigers” per 100 sq km.
  • Low density of tigers in the Sundarbans is an inherent attribute of the hostile mangrove habitat that supports low tiger prey densities.
• Human Interference
  • The consequence is frequent dispersal of tigers leading to higher levels of human-wildlife conflict in the reserve peripheries.
  • How the dispersal of wildlife is tolerated by people — from the locals who live around them to policymakers who decide management strategies also plays a crucial role on a reserve’s carrying capacity of tigers.
  • Social carrying capacity assumes wider significance for wildlife living outside protected forests, it is an equally important factor in human-dominated areas bordering reserves where periodic human-wildlife interface is inevitable.
  • More so when different land uses overlap and a good number of people depend on forest resources for livelihood.
  • Perceived conflict can squeeze the tiger’s domain, which the animal is bound to overstep from time to time, leading to further conflict with no immediate winners.

  

Way Forwards

• Increasing the Prey Base
  • Artificially boosting the prey base in a reserve is often an intuitive solution.
    • It can be counter-productive.
  • Striving to increase tiger densities by artificial management practices of habitat manipulation or prey augmentation.
• Minimizing External Threats
  • Tackling external factors, such as bushmeat hunting, is necessary to ease pressure on the tiger.
• Increasing Area and Connectivity
  • To harness the umbrella effect of tigers for biodiversity conservation, experts say, it is more beneficial to increase areas occupied by tigers.
  • For many, the prescription is to create safe connectivity among forests and allow tigers to disperse safely to new areas.
    • But though vital for genes to travel and avoid a population bottleneck, wildlife corridors may not be the one-stop solution for conflict.
• Minimizing Human-Wildlife Conflicts
  • As several studies have shown, removing tigers or any wildlife cannot eliminate the chances of future interface as another lot invariably turns up.
  • The remedy lies in smarter land use to minimize damage and adequate incentives to promote acceptance of wildlife.
  • Generous compensation policies can take care of the financial cost of losing livestock or crops, or wasted man hours when a workplace is avoided due to a passing tiger.
  • Besides, the percolation of financial benefits of having charismatic wildlife in the neighborhood can also nudge some towards better tolerance.

Conclusion

• Ultimately, it is the people of the Sunderbans who will decide how many tigers can be accommodated in their neighborhood.
• In a landscape squeezed in by climate change, rising sea level and salinity, their future is nearly as precarious as the tiger’s.
• It is for the policymakers to give them enough reasons to make a balanced choice.

Source: Indian Express

Mains Question:

Q. Explain How the optimal number of tigers in a forest is determined by physical and biological factors, and perceptions of conflict. (150 Words).