Sixty-thousand saiga antelopes in the steppe of Kazakhstan have died within four days, following the incident in May which had reduced the already-endangered saiga population to less than 125,000. Experts have yet to determine the cause.
Researchers from the Altyn Dala Conservative Initiative, led by geoecologist Steffen Zuther, arrived in Kazakhstan to monitor the calving of the saigas, but instead they witnessed a mass die-off of the species. News of similar cases in other parts of Kazakhstan had reached conservationists, stretching from May to June.
According to latest reports, researchers have found clues regarding the rapid deaths of the saigas. Zuther said that bacteria might have affected the herd, although it was still unknown how these normally harmless microorganisms were involved.
He also added that the speed and extent of the die-off has not been documented within other species.
In order to find some triggering source, field workers took samples of the environment such as the rocks, the soil, the water these animals drank, and the vegetation they ate in the months leading to the die-off as well as the ticks and insects that feed on them.
Necropsies of these animals were conducted by scientists and it was noticeable that the female saigas were struck the hardest. After the female saigas died, their calves soon followed.
Zuther explained the possibility that whatever was killing the saigas was spread through the mother's milk.
Meanwhile, tissue samples showed that Pasteurella and Clostridia might have produced toxins that caused extensive internal bleeding within the saigas. However, Pasteurella does not usually harm ruminants like saigas unless they have weakened immune systems.
There was nothing different with this genetic analysis as these bacteria were the garden-variety and disease-causing type.
Zuther said that one of the possible causes of this incident was the cold, hard winter trailed by a wet spring with lots of vegetation and standing water on the ground that enabled bacteria to spread more easily. This was not unusual.
Another probability is that such incidents are likely responses to some natural variations, he said.
Zuther and his colleagues will continue to search for the reason for the die-off.
Photo: Mark Herpel | Flickr