Wild Animal Birth Control: Politics vs. Science
The management of wild horse herds and urban deer populations is often embroiled in political controversy, overshadowing scientific solutions. Jay Kirkpatrick, from the Billings-based Science and Conservation Center, highlights how science is sidelined in favor of political agendas. His nonprofit organization produces PZP, a contraceptive vaccine for wild animals.
Wild horse populations on Western federal lands, such as the Pryor Mountain and McCullough Peaks ranges, have led to contentious roundups to control herd sizes. Similarly, urban deer populations have surged, prompting cities to implement reduction strategies, including trapping and hunting.
Kirkpatrick argues that these methods fail to address the root issue of reproduction. He explains that removing animals can lead to compensatory reproduction, increasing birth rates among the remaining animals.
PZP, derived from pig ovaries, prevents conception by causing antibodies in female animals to attack their own eggs. Like any vaccine, its effects diminish over time, necessitating booster shots.
The efficacy of PZP was demonstrated at Assateague Island National Seashore, where it maintained the wild horse population without the need for roundups. Kirkpatrick notes, "We stopped growth overnight and it took several years to start to decline."
The cost of darting one horse with PZP is approximately $106, compared to $2,165 for removing a horse in the Pryor Mountains.
Similar success was seen at Fire Island National Seashore, where the deer population was reduced by 70% through inoculation. Kirkpatrick humorously notes, "There are only two kinds of people on that island, deer haters and deer lovers, and they’re both happy."
Despite these successes, the Fire Island website mentions that complex issues prevented further research with PZP in 2010/11.
On Catalina Island, PZP reduced bison births from 29 to three in one year, aiming to maintain a manageable herd size.
Opponents argue that controlling which animals reproduce is unnatural and could affect herd genetics and social dynamics. Some state agencies prefer hunting as a population control method. Misconceptions about PZP, such as causing breast enlargement in men and sterility in women, have fueled opposition.
Kirkpatrick states, "All of what I’ve told you has been rolled in together to create a socially constructed ignorance." The core issue, he believes, is determining who benefits from public lands.
Comments Sought
The Billings Field Office of the Bureau of Land Management is seeking comments on a proposal to conduct fertility control on the Pryor Mountain Wild Horse Herd. Comments will be accepted until May 7.
To comment, write to Jim Sparks, field manager, at the BLM Billings Field Office, 5001 Southgate Dr., Billings, MT 59101. Or fax comments to 896-5281.
Originally Posted By Billings Gazette