A recent palaeoecological study has reconstructed the long-term ecological history of Kaziranga National Park, revealing how climate stability, vegetation change and herbivore activity shaped the survival and concentration of the Indian one-horned rhinoceros.

What did the study do?

• Scientists from Birbal Sahni Institute of Palaeosciences, under the Department of Science and Technology, analysed pollen grains and dung-fungal spores preserved in wetland mud.
• A sediment core (over one metre deep) was extracted from Sohola swamp inside Kaziranga.
• Each layer of sediment acted as a natural archive, recording past vegetation, climate and herbivore presence over nearly 3,300 years.

Key findings

• Indian rhinoceros was once widely distributed across the Indian subcontinent.
• During the late Holocene, climatic changes (including the Little Ice Age) and rising human pressures such as hunting and habitat loss led to megaherbivore decline in northwestern India.
• Northeastern India remained relatively climatically stable, with lower human interference, allowing rhinos to migrate eastward and eventually concentrate in Kaziranga.
• Kaziranga’s present grassland–wetland mosaic is very different from its past, shaped by floods, vegetation shifts, invasive species and grazing pressure.

About Kaziranga 

• Kaziranga, home to an estimated 2,613 one-horned rhinos and an estimated 32.64 tigers per 100 sq. km., currently has an area of 1,302 sq. km.
• The Kaziranga National Park is one of the oldest wildlife conservancy reserves of India, first notified in 1905 and constituted as Reserved Forest in 1908 with an area of 228.825 Sq. Km.
• It was specially established for conservation and protection of the Greater One Horned Rhinoceros (Rhinoceros Unicornis) whose number was estimated at twenty pairs then. 
• Kaziranga was declared a Game Sanctuary in 1916 and opened to visitors in 1938. 
• It was declared a Wildlife Sanctuary in 1950, and notified as Kaziranga National Park in 1974 under the Wildlife (Protection) Act, 1972, with an area of 429.93 Sq. Km.
• It was declared as a World Heritage site in 1985 and Tiger reserve in 2006.
• It is famous for the Big Five namely the Rhinoceros, Tiger, Elephant, Asiatic Wild Buffalo and the Eastern Swamp Deer. 
• The National Park is located in parts of Karbi Anglong, Golaghat, Nagaon, Biswanath and Sonitpur districts of Assam. 
• The Park HQ is at Bokakhat, on the NH 37 (now NH 715) which is also the Sub Divisional HQ of Bokakhat Civil Sub Division in Golaghat District.
• Kaziranga has five ranges namely 
  • Eastern Range at Agaratoli (north east of Bokakhat), 
  • Central Range at Kohora (west of Bokakhat), 
  • Western Range at Bagori (further west of Kohora), 
  • Burapahar Range at Ghorakati (further west of Bagori on the NH 37) 
  • Northern Range at Biswanath (west of Bokakhat).
• The Park is located between the Brahmaputra River in the north and the Karbi (Mikir) Hills in the south. 
• Other rivers flowing through the park include Mora Diphlu, Mora Dhansiri, Diphlu.

Significance for conservation

• The study shows that climate stability, habitat continuity and lower human pressure are critical for species survival.
• Palaeoecology provides valuable lessons for future wildlife management under climate change.
• Conservation planning must integrate long-term ecological evidence, not just present-day data.

One-line wrap

Mud beneath Kaziranga’s wetlands reveals how climate stability helped save the one-horned rhinoceros from extinction.

Exam Hook – 

Q. Consider the following statements regarding Kaziranga National Park:

1. Palaeoecological studies show that the Indian one-horned rhinoceros was once widely distributed across India.
2. Climatic instability and higher human pressure in northwestern India led to eastward migration of rhinos.
3. Long-term pollen and sediment analysis can help guide present-day conservation strategies.

Which of the statements given above are correct?
A. 1 and 2 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2 and 3

Correct answer: D

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