By Laura Zuckerman
SALMON, Idaho (Reuters) - Wildlife advocates are protesting a government plan to kill an undetermined number of bison from Yellowstone National Park after scientists conduct a birth-control experiment on the animals with an EPA-registered pesticide.
Government officials say the seven-year study by a branch of the Department of Agriculture seeks to lessen the prevalence of brucellosis, a disease that can cause domestic cows to abort, within the nation's last wild herd of pure-bred buffalo, or bison.
Brucellosis can be transmitted by female bison during calving season when the infectious bacteria are shed along with birthing fluids.
Yellowstone last month granted the federal Animal and Plant Health Inspection Service (APHIS) a permit to pen 49 young female bison and four bulls for breeding at a research facility outside the park. The animals are to be stock for an experiment involving as many as 100 bison from the 3,700-head herd.
Buffalo advocates say it is appalling that government scientists will conduct potentially harmful experiments on iconic animals that draw millions of visitors to Yellowstone every year.
They also object to the notion of chemically sterilizing animals of a wild herd targeted by ranchers because of a disease brought to North America centuries ago by European cattle. The Yellowstone bison are currently allowed to breed freely.
"The buffalo removed for the experiment are never going to be returned to Yellowstone, and their treatment -- being penned and bred like cattle -- is very inappropriate," said Dan Brister, head of the Buffalo Field Campaign.
USDA spokeswoman Lyndsay Cole said the project is aimed at curbing the spread of brucellosis from Yellowstone bison by using a contraceptive the government developed to control the reproduction of white-tailed deer.
"This product has presented signs of being an effective tool for preventing disease, and this is a study that could have a positive impact on that for brucellosis and bison," she said.
The contraceptive, GonaCon, is registered as a pesticide by the Environmental Protection Agency.
Cole said bison that test positive for contact with brucellosis would be killed at the end of the research project, though she said she could not yet provide a number. The plan is expected to be opened to public comment in the fall.
News of the research project came as Yellowstone released the last of nearly 700 buffalo captured this winter for migrating out of the park in search of food in nearby Montana. The 53 bison turned over for experimentation were culled from that group.
Montana's billion-dollar cattle industry bristles at the roaming bison because of worries about brucellosis.
(Editing by Steve Gorman and Peter Bohan)