Free-Living Animals on Birth Control
Why do we say there “too many” of the other animals? They all seem to balance themselves perfectly well until we intrude. Which we do, everywhere. Our population is seven billion and rising. As we spread ourselves out, we devise the cultural carrying capacity idea—introduced by the ecologist Garrett Hardin to mean the limit we declare on any animal community perceived as being in our way.
In North America, after we killed most of the wolves because ranchers and hunters didn’t want the predators around, deer achieved a notable ability to thrive in our midst. Yet they are pressed by our incessant construction and road-building into ever smaller and fragmented green places; and so they are described, in many areas, as having a high population density. Government officials, goaded by media representations that alarm the public, advance the conception of deer as a problem requiring a solution.
So officials make plans and draw up budgets that include tens of thousands of dollars for deer eradication, as with the pending plan for the U.S. Department of Agriculture to kill 5000 deer on Long Island. Advocates call it “primitive and ethically indefensible.” They hope the deer can be put on birth control instead. Their online petition says “overwhelming evidence” proves contraception is “effective, humane, less expensive and sustainable over the long term.”
But do we really want a patented, FDA-approved pharmaceutical plan to control other animals? So that we achieve an officially prescribed “density” of the animals in question for any given expanse of space? Is the bio-community that surrounds us something to refashion through some macabre, Disneyesque design?
And it’s not only the highly prolific animals being controlled. Humane Society International, the international arm of the Humane Society of the United States, vaunts its experiments with contraceptives on African elephants as “a new paradigm for elephant management” and garners financial support from the U.S. Fish and Wildlife Service.
But the population has dropped to less than a half-million, compared to some 3-5 million African elephants in the 1930s and 1940s. Highly vulnerable populations of long-tusked elephants, such as a genetically unique community of only 230 at KwaZulu-Natal’s Tembe Elephant Park, are being reduced through contraceptive testing—perhaps, warns Pretoria wildlife veterinarian Johan Marais, to fade into oblivion.
The Humane Society’s contraception experiments involve ultrasound exams and helicopter chases, with flights close enough to shoot elephants with darting rifles. Yet the group’s report on the project asserts: “Not only has immunocontraception proven to be the least invasive and most humane population control mechanism available to us, it proved to very effective in curbing population growth.”
What is humane about forcibly preventing these elephants’ existence? If elephant habitat is shrinking, isn’t that the real issue to address? And it’s not as though this intrusive activity replaces killing. The Humane Society maintains that “relocation and/or culling of elephants in confined reserves may continue to be necessary, but contraception will enable management to better control the frequency and extent of such interventions.”
Not only does contraception erase animals by preventing their offspring from existing; the science itself kills. For researchers at Cornell University and the U.S. Department of Agriculture, 21 white-tailed deer were captured, ear-tagged and collared, and kept in a fenced area at an army depot, with some subjected to multiple contraceptive vaccines. In October 2000, all were “humanely killed,” wrote the researchers, “by a shot to the head or neck from a high-powered rifle fired from a blind or a vehicle.”
The bodies were dissected to ascertain the effects of the vaccine known as porcine zona pellucida (PZP), the most commonly used immunocontraceptive for controlling female mammals. This substance, derived from the bodies of pigs, hijacks the deer’s immune system, making it attack the body’s naturally occurring reproductive proteins.
Most of the vaccinated group had lived with pelvic inflammatory disease, and abscesses the researchers called “remarkable”—tubercular in appearance even two years after the injections. The body of Deer Number 188 showed bone marrow fat depletion with “classic signs of malnutrition normally seen in deer struggling through an extremely harsh winter.”
Gary J. Killian and Lowell A. Miller had, just a few years earlier, published the results of six years of experiments at the Deer Research Center of the Pennsylvania State University. Deer subjected to PZP had fewer fawns, but the adults’ bodies changed so that “the average breeding days each year for the control group was 45, whereas in some years some PZP treated does were breeding more than 150 days” of the year. Thus are the social lives of deer—the schedules of their lives—commandeered by the chemical.
The researchers also tried a hormone-based substance. It stopped antler growth on male deer—whose testicles, and sex lives, also failed to develop. The female deer subjected to the hormone also failed to develop sexually.
And on it goes. A study proposal dated August 2013 and intended for implementation in 2014-2019 by Dr. Allen Rutberg at the Tufts- Cummings School of Veterinary Medicine proposes to use bait and drugs, possibly supplemented with drop-netting, to collect up to 60 female deer from Westchester County, New York. The deer will be immobilized, blindfolded and vaccinated in a comparative study of two types of contraceptive boosters, so as to predict the relative costs of using them for deer management.
Dr. Rutberg regularly contributes reports on this research to the Humane Society of the United States. Yet Rutberg’s description of collecting the deer, despite the clinical language, suggests the anticipation of a torment much like what humane groups are expected to prevent: “Processing after capture in net will include a thorough check for cuts, abrasions, and broken bones as a result of the capture and restraint.”
The Broader View
Meanwhile, the animals that naturally curb the deer population are treated as though their roles in nature don’t count. Eastern coyotes and bobcats, along with the wolves of the West, are persecuted legally and continually. Scientists are also experimenting with the sterilization of coyotes in order to protect the profits of sheep ranchers, and even wolves, low as their numbers are, have been subjected to such experimentation.
While the U.S. government enables ranchers to graze cows on public lands at below-market lease prices, and then “protects” agribusiness or “bolsters” hunting opportunities by killing carnivores such as wolves and coyotes, free-roaming horse populations are annihilated by federal employees on the ranchers’ behalf.
And forced contraception is passing for wild horse protection. The Annenberg Foundation has assisted the Humane Society of the United States with $1,756,850 in grant money for a project called “Assateague of the West: Protecting Wild Horses Through Immunocontraception.” The Humane Society introduced PZP to wild horse populations in 1988, assisted by federal park administrators and the Bureau of Land Management. Under the law, the BLM is to “preserve and maintain a thriving natural ecological balance.” Yet cattle vastly outnumber the free-roaming horses. Erasing free-roaming horses supports ranchers’ financial interests, and not the horses’ best interests. Why can’t the Humane Society let the horses and burros be, and put serious work into resisting the commercial exploitation of public lands?
As for the direct physical and social effects of the contraceptives, some studies on horses suggest few drawbacks while others reveal the opposite. Cassandra M.V. Nunez et al. found that contraception with PZP significantly alters the social lives of the horses of Shackleford Banks, North Carolina—enough to destabilize equine group dynamics. As usual, the researchers called for more research.
The population levels of herbivores, to the extent that they do grow, are a direct result of humankind’s past and present dominion over their natural predators; and biologists have, time after time, found that free-living populations cannot be better managed by humans than nature itself. It’s time to stop mistaking human control for humane treatment.
Lee Hall is a candidate for Vermont Law School’s LL.M. in environmental law (2014). Lee has taught animal law and immigration law, and worked for more than a decade in environmental and animal advocacy. Follow Lee on Twitter: @Animal_Law