Update 9 June 2015: More than half the world's enigmatic saiga antelopes – some 134,000 animals – have been wiped out in Kazakhstan within just three weeks. The culprit has been identified as haemorrhagic septicaemia, caused by the bacterium Pasteurella multocida, according to the World Organization for Animal Health, which says the outbreak is now over. 
 
 Original article, published 27 May 2015 
 
 The death toll of iconic saiga antelopes in central Asia has soared to around 120,000, almost half of the world's remaining population, according to unofficial estimates. Today vets and scientists investigating the catastrophe presented their results so far to government officials in Kazakhstan, where the animals are dying. 
 
 "The current official figure is 85,000, but we are hearing unofficial estimates in excess of 100,000, approaching 120,000," says Aline Kühl-Stenzel of the UN Convention on Migratory Species. 
 
 The animals began dying from an unidentified cause around 10 May. The death toll soared within days to 27,000, at which point the Kazakh government requested help from the secretariat of the convention. A team of vets, led by Richard Kock of the Royal Veterinary College in Hatfield, UK, flew out on Friday. 
 
 "It's very dramatic and traumatic, with 100 per cent mortality," Kock told New Scientist from Betpak-Dala in central Kazakhstan. "I know of no example in history with this level of mortality, killing all the animals and all the calves." The animals die through severe diarrhoea and difficulty breathing. 
 
 Trio of possibilities 
 
 From tissue samples collected earlier by Kazakh researchers, Kock and colleagues have narrowed the cause to three possibilities. One is haemolytic septicaemia, caused by bacteria that are normally harmless, and which also kills buffalo. 
 
 Another, less likely culprit is epizootic haemorrhagic disease, a viral disease transmitted by mosquitoes. "We have to do more tests to rule that out," says Kock. The other possibility is toxaemia caused by clostridia bacteria. "We need all the lab tests to be completed and a comprehensive analysis before we can reach any firm conclusions." 
 
 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. 
 
 In 2014, there were an estimated 200,000 animals in Betpak-Dala, with a further 60,000 in other regions of central Asia, down from more than a million saiga in the 1990s. 
 
 If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to. ||||| KIEV, Ukraine (AP) — Authorities in Kazakhstan says around one-third of the endangered saiga antelope population in this Central Asian nation has mysteriously died off in the last few days. 
 
 Kazakhstan's agriculture ministry said Friday the number of saiga that have died may have reached 85,000. 
 
 The ministry says it suspects the animals, which are recognizable for their distinctive humped snout, may have been struck by an epidemic of pasteurellosis caused by a bacterial infection. Officials say international veterinarian experts have been flown to Kazakhstan to study other possible causes for the catastrophic die-off. 
 
 The number of saiga plummeted in the 1990s as a result of poaching. At the latest Kazakh government count in 2014, the saiga population stood at 257,000. 
 
 Saiga are also found in smaller numbers in parts of Russia.
– After many thousands of years roaming much of central Asia, the saiga antelope has had a terrible couple of decades—and a devastating few weeks. A mysterious illness that causes severe diarrhea and breathing difficulties has wiped out what could be up to half of the remaining population of the species, New Scientist reports. Officials in Kazakhstan say the disease has killed 85,000 of an estimated world population of 257,000 since about May 10, but experts say they've heard unofficial estimates closer to 120,000. The species—known for its distinctive tubular nose, the AP reports—numbered more than a million in the 1990s but has been in decline since, thanks in large part to poachers, and was already considered critically endangered before the latest die-off. "It's very dramatic and traumatic, with 100% mortality," the leader of an international team investigating the outbreak tells New Scientist. "I know of no example in history with this level of mortality, killing all the animals and all the calves." The team, which has been taking soil and vegetation samples, believes the mass deaths may have been caused by a bacterial infection or by a virus carried by mosquitoes, Smithsonian reports. Whatever the culprit, it has been able to cause a staggering death toll because the population's females all have their calves in the same week, allowing disease to spread quickly, New Scientist notes. (In better news for an endangered species, the US government says most humpback whale populations have rebounded.)