International experts are investigating the sudden deaths of more than 100,000 endangered saiga antelope in Kazakhstan, raising fears that a species that has been around since the Ice Age may be at risk of dying out. Around 40 per cent of the Central Asian nation's population of the endangered saiga antelope have died in the past two weeks. Animal health experts suspect a respiratory disease may be to blame. Kazakhstan, the world's ninth-largest country by area, is home to around 90 per cent of the world's population of the saiga, recognisable by their lyre-shaped horns and bulbous noses. "The death of the saiga antelope is a huge tragedy," zoologist Bibigul Sarsenova said. "Should this happen again next year, they may simply disappear." The International Union for Conservation of Nature, a global coalition of governments and environmental organisations, says the saiga antelope is a "critically endangered" species. An estimated 300,000 saiga roamed across the Kazakh steppes on May 11, when the first dead antelope was discovered. By May 27, nearly 121,000 carcasses had been found in three huge areas of their usual habitat. "We believe the cause of the deaths is pasteurellosis," Yerzhan Madiyev, deputy head of the Agriculture Ministry's veterinary committee, said. Pasteurellosis is a bacterial disease that can infect humans and cattle, rabbits, cats and dogs. Its bacteria occur naturally in the upper respiratory tract, but can be harmful when the immune system is compromised. Scientists are testing soil, air and water to try to solve the mystery of the mass deaths, the Agriculture Ministry's forestry and wildlife committee said. Huge herds of saiga once roamed the earth alongside the woolly mammoth and the sabre-toothed tiger. The mammoth and tigers died out but the saiga became prized for its meat. There were more than 1 million saiga in the 1990s, but by 2003 poaching and disease slashed their numbers in Kazakhstan to 21,000, Azbayev said. Two years later, the government adopted a plan to protect them and numbers rebounded.