Federal officials want the public’s help in curbing Oregon’s growing wild horse population.
The Bureau of Land Management has asked for comment on three birth-control methods. The agency currently administers a birth-control vaccine that lasts up to two years but is looking for contraceptives that last longer.
Oregon is currently home to about 4,500 wild horses. Sarah Bennett, a spokesperson for the agency’s Portland office, said Oregon can sustain about 2,700.
Most wild horses in Oregon are in the southeast corner of the state near Nevada. Agency officials say they overgraze native plants, allowing invasive species to proliferate, and threaten other wildlife. They also affect water supplies.
Not everyone agrees that Oregon has too many horses. Wild horse conservationists say the bureau needs to better manage land to provide ample habitat for the horses and to expand the use of the contraceptive it already uses, rather than investing in new ones.
The public has until August 22 to comment. Afterwards, the agency will publish a decision on approving any of the project and, if approved, testing would begin in late 2022 and last up to five years.
It’s proposing to test three contraceptives.
Two are vaccines and one is an intrauterine device, or IUD, which prevents the horse’s menstrual cycle.
“This would be the first study of IUDs in wild mares living on the range with fertile stallions,” Bennett said.
One of the vaccines, causes an immune reaction that disrupts egg development and has proved to be safe in horses. The other vaccine, SpayVac, is similar to the current method of birth control the agency uses but is longer lasting. It has been tested before but had a lower efficacy rate. Higher quality versions of the vaccine are being made, and the agency would try injecting it in the neck and hind leg muscles to see if one is more effective.
For the complete story, see the Oregon Capital Chronicle.
