Lying to the west of the Aravalli Mountains, the Thar Desert is the seventh-largest desert in the world, encompassing much of northwestern India. The Thar contains several distinct ecosystems, including shifting sand-dunes, arid rocky plains and semi-arid high desert mountains along the foothills of the Aravalli Range. An abundance of wildlife and vegetation thrives despite the inhospitable climate, adapted to withstand the extreme temperatures and scant rainfall characteristic of the region.
Several species of tree exist along the rocky valley floors and seasonal flood plains of the Thar desert, clinging to sheltered areas or places with subsurface water. The sangri tree (Prosopis cineraria), a relative of the acacia, is a small spiny tree found in alluvial plains of Punjab and Rajastan.
It is one of the most common trees in the Thar desert, known for its bluish, evergreen foliage and small yellow flowers, which appear in late spring and early summer. Prized by people of the Thar desert, the rohida (Tecoma undulata), or desert teak, is an evergreen tree species found throughout western Rajastan. Used for lumber, rohida is also admired for its winter display of reddish-orange flowers.
Shrubs thrive throughout all areas of the Thar desert, from the shifting dunes to the semi-arid foothills of the Aravalli Range. Phog (Calligonum polygonoides), a small medicinal plant, is the predominant shrub across the Thar. Growing to 5 feet on average, phog bears tiny, yellowish-green leaves that it sheds during times of stress. Along the southern reaches of the Thar, near the expansive salt-flats of the Rann of Kutch, a small shrub called khar (Haloxylon recurvum) thrives. Growing to 2 feet, khar is a spreading, woody shrub bearing only a scattering of pale greenish-yellow leaves.
Grasses, the predominant flora of the region, abound in all areas including the vast, barren dunes. Kans grass (Saccharum spontaneum) and blue panicgrass (Panicum antidotale) are among the most widespread grasses found in the Thar. Growing to 10 feet, Kans grass is a native perennial grass found in the semi-arid savannah of Punjab. It provides forage for the Thar's many herbivorous species, such as gazelle and nilgais. Blue panicgrass shares much of its range with Kans grass, thriving in areas rich in herding wildlife. It spreads rapidly via underground rhizomes, producing 11-foot-tall stalks topped with feathery seed heads.
A variety of fauna call the Thar desert home, including several species of gazelle. The chinkara, or Indian gazelle (Gazella bennettii), is a tiny, fine-boned gazelle species known for its handsome reddish-beige colouring and delicate spiral horns. Young chinkaras sometimes fall prey to a common predatory feline of the Thar, the caracal (Caracal caracal). Lithe and muscular, caracals are closely related to the European lynx, sharing the characteristic tufted ears and long legs of the species. The largest and most common species of gazelle in Asia, the nilgai (Boselaphus tragocamelus) thrives across the Thar desert. The colouration of nilgais ranges from beige in females to greyish-blue in males, leading to the common name, blue bull.
Among the diverse bird life found in the Thar desert is the great Indian bustard (Ardeotis nigriceps), a rare and endangered species known for its large body and deep, resonant call. Once widespread throughout India and Pakistan, the great Indian bustard suffered declining numbers due to hunting. Standing 40 inches tall and weighing as much as 6.8kg., it is among the largest flying birds on Earth. Likewise, the blue peafowl (Pavo cristatus) is a large species common throughout the Punjabi areas of the Thar desert. Known for its brilliant multicoloured plumage, the blue peafowl is a sacred bird throughout the region, as well as being India's national emblem.