Rare Antelope on Brink of Extinction, Scientists Say
By John Roach
for National Geographic News
|April 25, 2003|
Male saiga antelopes face a serious problem that threatens to push them over the brink of extinction: so many females, so little time.
The global population of this antelope, native to the steppes and deserts of Central Asia and the Pre-Caspian region of Europe, has fallen by 80 percent to approximately 50,000. In the mid-1970s, the peak population was more than 1,250,000. Of the saiga antelopes that remain, most are female.
The males simply cannot mate with enough females to maintain a viable population, said Eleanor Milner-Gulland, a conservation scientist at Imperial College London in England.
"The population is crashing at the moment, losing 50 percent of its individuals a year," she said. "This is a rapid trajectory towards extinction."
Milner-Gulland and colleagues from Russia and Kazakhstan published a report on the reproductive collapse of the saiga antelope (Saiga tatarica) in the March 13 issue of the journal Nature.
The primary reason for the collapse is over-hunting by rural communities that were economically devastated following the breakup of the Soviet Union. Rural farmers hunt both sexes of the three foot (one meter) tall antelopes to feed their families.
The animals have long noses and short, pointed antlers. Gangs of poachers zip around the countryside on motorcycles shooting the males for their horns, which sell for as much as U.S.$100 in China where they are used to treat heart disease, fever, stroke and other conditions.
The disproportionate hunting of the males for their horns has caused an imbalance of the sexes. Competition for the few males is now so fierce that dominant females actively push young, would-be mothers out of the picture. Such behavior in a harem-breeding species has never before been observed, said Milner-Gulland.
In 2002, the saiga antelope was listed as Critically Endangered by The World Conservation Union (IUCN) and listed on Appendix II of the Convention of Migratory Species. Conservationists argue that unless national anti-poaching laws are enforced, the species may be extinct within the next few years.
"At the end of the day, people will end up hunting saiga if there are no other options for them, so part of the answer also lies in ensuring that the people living closest to the saiga can recognize the need for their long-term protection," said Abigail Entwistle, a zoologist with Fauna & Flora International, a conservation organization in Cambridge, England.
Too Many Females
The saiga antelope once roamed the open lands of Europe and Central Asia from Ukraine to Mongolia in herds of up to 100,000 animals. Migrations covered up to 621 miles (1000 kilometers) between their summer and winter feeding grounds. A male antelope traditionally maintains a harem of 12 to 30 females.
Female saiga antelopes are sexually mature at eight months of age, males at 20 months. Normally, the antelopes live six to ten years.
Scientists assumed that in polygynous systems the males are able to secure the viability of the population by mating with as many females as possible. Milner-Gulland and her colleagues report that there is a point at which the males cannot keep up.
"In November 2000 there were 106 females for every adult male, which was clearly too many for the males to handle," said Milner-Gulland. Although the scientists do not know exactly where the breaking point is, their study puts it somewhere between 36 - where the antelope managed to mate successfully - and 106 - where they did not.
This unexpected reproductive collapse, compounded with the over-hunting of both sexes for their meat, forecasts an uncertain future for the saiga antelope.
"The species is adapted to a boom-bust population cycle, and has gone through population crashes previously, however the research by Dr. Milner-Gulland and her colleagues suggest that if the reproductive rate is undermined the possibility for future recovery may be undermined," said Entwistle.
Conservationists point out that the rise of the Soviet Union in the early 20th century and a strict ban imposed on hunting allowed the saiga antelope to recover from a similar population crash during the 19th century. This may auger well for the saiga antelope population today.
Fauna & Flora International is working with Milner-Gulland and her colleagues to secure funding for an initiative to restore a viable population of saiga antelope in central Kazakhstan. The population was over 500,000 but is now just 4,000 animals.
"The main issue is enforcement as most of the laws are in place to protect the species in its natural ranges," said Entwistle. "However, protecting a species that ranges over such large areas is logistically very difficult."
To do this, the conservationists are asking the international community to fund the establishment of mobile anti-poaching units to deter illegal hunting and provide educational outreach to the local communities.
"A relatively small injection of cash and support for local law enforcement agencies could go a long way towards saving this species" said Milner-Gulland.
|© 1996-2008 National Geographic Society. All rights reserved.|