The saiga, a critically endangered Asian antelope species, has been decimated by a mysterious, fast-moving disease. In the past two weeks, more than third of all saigas have been killed, conservationists have found.
The cause of the outbreak is unknown, but scientists believe it is always fatal.
“I’m flustered looking for words here,” said Joel Berger, a senior scientist at the Wildlife Conservation Society. “To lose 120,000 animals in two or three weeks is a phenomenal thing.”
Before the end of the Ice Age, saiga lived over a vast range stretching from England to Alaska. After the climate warmed, they continued to thrive on the steppes of Central Asia.
After the fall of the Soviet Union, however, the saiga population fell by more than 95 percent. Poachers were mainly responsible, killing the animals to sell their horns in China for use in traditional medicines.
In 2006, the five nations where saiga still survived — Kazakhstan, Mongolia, Russia, Turkmenistan and Uzbekistan — signed a memorandum of understanding to conserve the species. Anti-poaching measures have helped the population recover from less than 50,000 to about 250,000 before the current die-off.
“It was a big success story,” said Eleanor J. Milner-Gulland, the chair of the Saiga Conservation Alliance.
Earlier this month, Aline Kuehl-Stenzel, the terrestrial species coordinator of the Convention on the Conservation of Migratory Species of Wild Animals, an environmental treaty overseen by the United Nations, received a report from the Kazakhstan government that hundreds of saiga had suddenly died, including many mothers with nursing calves. The death toll has continued to climb ever since.
Many species of grazing mammals suffer periodic die-offs, which can be caused by drought or viruses such as rinderpest. But because the saiga population is so reduced, the current die-off has claimed a huge proportion of the species.
“The scale is absolutely unprecedented,” said Dr. Kuehl-Stenzel.
Recently Richard A. Kock, an expert on wildlife disease at the Royal Veterinary College, and his colleagues went to Kazakhstan to help with the investigation. They examined dead animals, performing necropsies on 15 of them.
The scientists found that once the disease struck a herd, it killed every animal. “It is an extraordinary thing to get one hundred percent mortality,” Dr. Kock said.
Click here to read more.
SOURCE: NY Times, Carl Zimmer