Geo-ecologist Steffen Zuther, international coordinator of the Altyn Dala Conservation Initiative, shared that in the last years, saigas, a critically endangered, steppe-dwelling antelope, have died but in limited number. But extremes happened within four days when the entire herd, 60,000 saigas, died. Not only in central Kazakhstan, also in other herds across Kazakhstan, has similar thing happened.

Researchers are working on how this has actually happened and they have found some clues. More than 50% of the country's' herd, which was 257,000 as of 2014, has died so quickly. As per the researchers, bacteria have played a role in the deaths. But for now, it is not known that whether such harmless bacteria can prove so disastrous.

Zuther said, "The extent of this die-off, and the speed it had, by spreading throughout the whole calving herd and killing all the animals, this has not been observed for any other species. It's really unheard of".

The International Union for the Conservation of Nature has listed saigas as critically endangered. There are few that live in Kazakhstan, one small herd in Russia and a herd in Mongolia.

Researchers shared that in recent years, die-offs of saigas have happened. When massive deaths took place this time, field workers took samples of saigas' environment. Researchers also took samples of the ticks and other insects that walk and feed on saiga.

They have also carried out necropsies of the animals and observed the behavior of some animals as they died. The females died first followed by their calves. It led researchers suggest that the thing that was killing the animals was being passed through mothers' milk.

Researchers found that toxins produced by Pasteurella and possibly Clostridia bacteria have led to extreme bleeding in most of the animals' organs. Zuther said he and his colleagues are planning to continue their research to know the reason behind die-off.