BEIJING -- Forestry officials in far western China have resorted to scattering abortion pills near gerbil burrows in a bid to halt a rodent plague threatening the region's ecosystem, state media said Wednesday.
The pellets, which resemble bran feed, have "little effect on other animals" but can prevent pregnancy in gerbils and also induce abortion in already pregnant females, the official Xinhua News Agency said.
In 2003, officials installed hundreds of perches for owls and eagles, hoping the birds would cut back the rodent population, but gerbils have continued to be a problem, it said.
Gerbils use too much of the area's limited grass to make their burrows and damage plant roots with their underground digging, it said.
Desertification is a major concern for China. Deserts currently cover about one-third of the country and officials fear global warming will accelerate their expansion.
The report did not say what was in the "tailor-made" contraceptive pellets, which have been used in the Gurbantunggut desert since May of last year.
"It's a good way to tackle the desert rat plague," local forestry official Du Yuefei was quoted as saying.
Du, chief of the epidemic prevention division of the Changji city forestry bureau, told Xinhua 200 kilograms (440 pounds) of the drug was strewn over 49,000 hectares (120,000 acres) last year and cost the bureau 80,000 yuan ($11,400).
There's been a slight drop in gerbil numbers since the program was started, Du said, with about 11 gerbils now caught for every 100 traps laid out. Previously, 12 gerbils was the average.
Contraceptive pellets have been mixed into bird feed in St. Paul, Minnesota to help rein in that city's pigeon population and officials in Los Angeles have used contraceptive injections on squirrels. Animal rights groups often support contraception as a humane alternative to killing animals deemed pests.