The saiga antelope is a fawn-colored, goat-sized creature with a floppy, tubular nose that lives in the grasslands of Central Asia and Eastern Europe. Hunting and habitat loss pushed the animal onto the the endangered species list, but there were some indications that it was making a comeback. That is, until a mysterious disease started killing them.
For New Scientist, Andy Coghlan reports that unofficial estimates indicate that in the last month about 120,000 animals, or half the world’s population, have died.
An estimate from 2014 put the saiga’s population at about 260,000 animals worldwide. But once, the saiga roamed from the British Isles to Alaska along with saber-tooth tigers and woolly mammoths. The recent deaths are due to severe diarrhea and breathing difficulties. "It's very dramatic and traumatic, with 100 per cent mortality," Richard Kock of the Royal Veterinary College in Hatfield, UK told New Scientist. He is onsite in central Kazakhstan. "I know of no example in history with this level of mortality, killing all the animals and all the calves."
The Ministry of Agriculture of Kazakhstan reported the problem earlier this month. Within days, the death toll reached more than 27,000, according to the Convention on the Conservation of Migratory Species of Wild Animals (CMS), an environmental treaty overseen by the United Nations. The CMS website reports:
Saiga populations do from time to time suffer from mass mortality events. The most severe known case happened in 1984, when about 100,000 (67 per cent) of the saigas died in the Ural population in Kazakhstan. However, the current case is already the third mass mortality episode to have occurred in recent years. In the two other cases, similar symptoms caused the deaths of saigas in the Ural population in western Kazakhstan in May 2010 and May 2011, claiming the lives of 12,000 and 500 individuals respectively. The causes of the previous mass mortality incidents could not be conclusively identified.
Coghlan reports for New Scientist that tissue samples are helping researchers figure out what might be causing the illness. They have identified three possible causes: Haemolytic septicaemia, a bacteria that is typically harmless but can kill buffalo; Epizootic haemorrhagic disease, a virus carried by mosquitos; or toxaemia (blood poisoning) caused by clostridia bacteria. Coghlan writes:
The reason so many animals died at once is linked to the fact that the local females all calve within one week, providing ideal conditions for disease to spread between the animals and to their calves.
Researchers are out in the fields now sampling soil and vegetation to help figure out the cause of this unknown but devastating disease.