Surviving in India’s salt desert

The Rann of Kutch evolved when waters of the Arabian Sea made incursions into this region 150-200 million years ago. Geological upheavals led to the rise of a landmass that cut off the Kutch basin from the sea.

The Rann of Kutch evolved when waters of the Arabian Sea made incursions into this region 150-200 million years ago. Geological upheavals led to the rise of a landmass that cut off the Kutch basin from the sea. The Little Rann of Kutch lies at the end of the Gulf of Kutch and covers an area of 5,000 sq.km, chiefly in the Surendranagar district of Gujarat.

For most of the year, this landscape consists of vast, barren and white salt flats. A striking alteration occurs when the monsoon sets in, and the Rann turns into a shallow wetland. About 75 elevated pieces of land turn into islands, called bets by the local Agariya and Maldhari communities.

The Little Rann of Kutch is home to the wild ass sanctuary, which is the only remaining habitat of the Indian wild ass (Equus hemionus khur), locally called khur. About 6,000 of these sandy and brown creatures live in this area. The terrain they occupy is harsh through most of the year, and the vegetation is dry and xerophytic. Khur, like donkeys and other members of the Asinus subgenus, possesses a remarkable ability to locate sustenance in desolate environments. Their digestive systems are adept at processing even the most arid vegetation. The khur has outlasted predators such as the cheetah and the lion, which were last spotted in this region in the 1850s.

The khur is almost the size of a zebra, and lives for 21 years. Stable groups of khur consist of females and their young. Stallions tend to be loners, especially in the breeding season. On the flat terrain of the Rann, they are capable of bursts of up to 70 km per hour. Life can be tough for the mares, as gestation periods are long, 11 to 12 months, and concurrent lactation and pregnancy is sometimes seen.

Back from the brink

The khur have recently overcome a near-extinction event on account of diseases. The viral African Horse sickness, and Surra (caused by the protozoan parasite Trypanosoma evansi and spread by biting insects) had decimated many herds, and only a few hundred survivors were estimated in the 1960s.

Analysis of the mitochondrial DNA of the khur by scientists at the Government Vidarbha Institute of Science in Amravati has indicated a low level of genetic diversity. This is because of a genetic bottleneck caused by disease outbreaks, which left only a small number of survivors. Thanks to persistent conservation efforts, the population of the khur has shown an upward trend in recent decades.

Conflicts with humans

The salt marsh attracts human enterprise — 30% of India’s salt comes from the Little Rann. Every year, a seasonal migration transforms this mirage-like landscape, bringing in 5,000 families and a surge of heavy vehicular traffic. This influx, coupled with extensive cattle grazing, poses a major threat to the delicate ecosystem and its wildlife. Irrigation canals that bring water to the southern rim of the Little Rann can also add salinity to the soil.

Increased human presence, both for salt farming and agriculture, has led to a dispersal of the khur. Herds are seen in adjoining areas of Gujarat and even Rajasthan. In the process, the wild ass has acquired the reputation of a crop raider. Other animals such as the nilgai and feral pigs cause more damage to crops, but the khur gets disproportionately blamed. A proper separation of the sanctuary’s starkly beautiful landscape from human-dominated areas would be better for both.

(The article was written in collaboration with Sushil Chandani, who works in molecular modelling)

Published - September 28, 2024 09:12 pm IST