The wild asses of Kutch

The whole of the Little Rann of Kutch, a tidal salt marsh with an area of nearly 5000 square kilometers, is a sanctuary for the Indian wild ass (Equus hemionus khur). The IUCN red list calls it near-threatened because its population has been increasing since 1972 when the area was declared to be a sanctuary, and now has reached a level of 2000 mature individuals. Unfortunately, this is the only population of these animals anywhere in the world. My first view of this animal came in the morning of my second day in the desert. A family group of about a dozen animals were spooked when we arrived and began walking away from us. There was a little bit of a panic, which never broke into a run, presumably because we kept our distance. As you can see in the featured photo and the one below, there was still a little jostling, because no individual wanted to bring up the rear.

This population is the last surviving subspecies of the Asiatic wild ass in the whole of south Asia. There are four groups of E. hemionus remaining in the world; in addition to the one that we saw, there is the endangered populations of E. h. onager in Iran and Turkmenistan, and the E. h. kulan in Mongolia. DNA analysis of 52 individuals showed extremely low genetic diversity. The species diversified during the recent ice ages, perhaps around 6,50,000 years ago. During the time that this species spread across Asia humans probably did not come into extensive contact with it. However, the study also found an indication of a severe population bottleneck of the Indian subspecies which was coincident with the rise and spread of the Indus Valley civilization. So it would seem that it is not only the total number of animals which is of concern, but also the conservation of its genetic diversity.

We saw several kinds of groups. There were groups with 10-20 members, like the first one we saw. Then there were groups which looked like a breeding pair with juveniles, as in the photo above. We also saw an occasional single individual. An extensive study of the social organization of the asses did not list the “nuclear families” that we spotted on and off, but reported extensive fission of the larger groups. So it is possible that the groups of three or four we saw were either far-ranging members of a larger group, or part of a group which had broken up and was to reform soon. The single individuals were likely to be territorial stallions.

I wondered what they were eating. Adesh pointed out a low spreading herb which the asses seem to like. I broke off a little piece, and nibbled on it. It was salty. Was the salt just blown on to the vegetation from the desert or did it take up the salt from the ground? These animals must have evolved ways of living in a salty marsh. We know today that much of our ability to eat different foods is due to the bacteria which we grow in our guts. This is not a peculiarly human ability; salt tolerating bacteria may have been found in the guts of these asses. I loved the sight of these wonderful animals roaming a harsh desert, but it seems that the biology which makes it possible is also wonderful.