The story of the one-horned rhinoceros in Assam’s Kaziranga National Park (KNP) showcases the impact of climate change, vegetation shifts, invasive species, and herbivore activities on its evolutionary journey. The region faces escalating ecological degradation due to rapid urbanization, industrialization, deforestation, coupled with natural disasters such as floods and landslides, contributing to the accelerated loss of biodiversity, particularly in Northeast India, a significant part of the Indo-Burma biodiversity hotspot.
The ongoing global issue of megafaunal extinctions raises concern, particularly as nearly 60 percent of large herbivores are now threatened, with Southeast Asia facing the highest risk. Kaziranga National Park, recognized as a UNESCO World Heritage Site, serves as a vital refuge for megaherbivores, especially the Indian one-horned rhinoceros.
Research conducted by scientists from the Birbal Sahni Institute of Palaeosciences (BSIP), under the Department of Science and Technology (DST), has provided valuable insights by analyzing pollen from the sediment beneath KNP’s wetlands. This study, published in the journal ‘Catena,’ revealed the first long-term palaeoecological records concerning palaeoherbivory in KNP. The team took a sediment core from the Sohola swamp, which represents a natural archive of historical ecological data, including pollen grains and fungal spores indicative of past environmental states.
Their findings illustrate a stark contrast between Kaziranga’s current landscape and its historical ecology, indicating the regional extinction of megaherbivores, like the Indian rhinoceros, from northwestern India due to climatic changes, particularly during the Little Ice Age, aggravated by human activities. Inferred from fossil evidence, the study identifies that, whereas northeastern India maintained relative climatic stability with lower human impact, causing rhinoceroses to gradually concentrate in Kaziranga, other regions endured habitat loss and urbanization pressures that drastically diminished the species’ distribution across the Indian subcontinent since the Holocene.
The researchers conclude that the long-term climatic and vegetational shifts have substantially influenced wildlife evolution, migration, and extinction patterns. This ecological knowledge is critical for informing contemporary conservation efforts and wildlife management strategies in the context of ongoing and future climate change challenges.
