BLM Plans to Test Contraceptives on Black Mountain Burro Herd

Jan 28, 2016

The U.S. Bureau of Land Management (BLM) hopes to test experimental contraceptives on the overpopulated Black Mountain burro herd near Kingman.

Credit Rylee Isitt/WikiCommons


The BLM estimates 1,400 to 1,800 wild burros roam the Black Mountains in Mohave County. That’s three times the number the agency deems acceptable for the ecosystem.

Spokesperson Jayson Barangan says the BLM is considering a contraceptive called PZP. “What we’re trying to do right now is explore opportunities for new and innovative methods for managing burros,” he says. “PZP is a safe and humane treatment that’s been used to control wild horse populations.”

The drug would likely be injected by hand after burros are captured. It wears off after a year or two. This will be the first time it will have been tested on wild burros. The BLM hopes to complete an environmental analysis and begin field trials later this year.

Pat Barber of the Arizona Game and Fish Department says contraceptives alone won’t reduce the population to the required number, called an Appropriate Management Level (AML). “If and when they develop a contraceptive approach that could be effective, they first need to reduce the population down around AML so they can maintain them there,” he says.

Barber says the BLM should step up its adoption program to bring the numbers down.

For further information, see the 2013 National Academy of Sciences report that identifies PZP as one of the most promising fertility control methods. See also the Arizona Game and Fish Commission’s recent resolution calling for action on the burro issue.