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The Aravalli hill range is a keystone ecological system in western India. While it is commonly associated with limiting the eastward spread of the Thar Desert, its more critical function lies in acting as a major biological corridor, enabling species movement, genetic exchange and long-term landscape-level biodiversity persistence.
Biological corridors are broadly categorised into upland corridors, formed by elevated terrains, and lowland corridors, such as riverine and drainage networks. The Aravalli range constitutes one of India’s most significant upland corridors, facilitating wildlife dispersal and seasonal migration across biogeographic zones. Concurrently, rivers and rivulets along both flanks of the range create complementary lowland corridors, enhancing overall ecological connectivity.
Over two dozen protected areas are aligned along the Aravallis in a near-continuous chain. Functional connectivity among these sites is essential for maintaining viable, resilient wildlife populations.
The Aravallis also play a crucial role in long-distance bird migration. Several migratory bird species arriving from northern latitudes use this landscape as a temporary stopover before undertaking energy-intensive crossings of the Thar desert, Arabian desert regions, or the Arabian Sea on their journey towards Africa. The availability of diverse habitats, high-quality food resources, and relatively secure resting sites allows these birds to replenish energy reserves essential for successful migration. A notable example is the Common Cuckoo, for which field evidence indicates migration from East Asia, with individuals halting in the Jhalana region of the Aravallis before continuing their journey. Such observations highlight the Aravallis’ importance as a critical stopover habitat within the global network of intercontinental migratory routes, extending its ecological relevance far beyond the Indian subcontinent.
Rajasthan occupies a strategic position in western India, acting as a transitional zone for species moving from northern and central regions into other parts of the country. The Aravallis and associated hill systems provide essential habitat and refuge, particularly for wide-ranging species such as leopards, sloth bear, hyenas and wolves. This ecological buffering and availability of natural shelter contribute to the relatively low levels of human-wildlife conflict observed in many parts of the state.
From a spatial perspective, the ecological footprint of the Aravallis is often underestimated. While the base area of the range is estimated at 5,000-7,000 sq km, inclusion of slopes, ridges, pediments and eroded terrain increases the effective ecological surface area to 8,000-10,000 sq km. This landscape supports a mosaic of habitats that sustain a variety of plant and animal life. On both flanks of the Aravalli range, piedmont aeolian sand dunes have developed through the deposition of wind-blown sands from the Thar desert. These zones function as natural buffer systems. The rocky and uneven core of the Aravallis serves as a secure refuge for wildlife, offering shelter during the day and access to surrounding foraging grounds at night. This interface supports desert-adapted species such as reptiles (royal snakes, desert monitor lizards, fringe toed lizard), mammals (hyenas, white-footed foxes, Asiatic wildcat and, alongside forest-associated species like leopards, and historically, tigers). Renewed conservation initiatives have reopened discussions on the potential recovery of tigers in suitable parts of the Aravallis.
The Aravalli range is equally vital for water security. In many of Rajasthan’s groundwater-stressed “dark zones”, recharge remains possible primarily because of this hill system. Although intensive agriculture is limited, fractured and rocky terrain efficiently captures and percolates rainfall into aquifers. In the context of climate change, degradation of the Aravallis would have serious impact on regional temperatures, wind patterns and hydrological stability.
(Dharmendra Khandal is a conservation biologist with Tiger Watch)
This column was originally published as part of the cover story Chaos in definition in the January 16-31, 2026 print edition of Down To Earth