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Deerly Held Beliefs: Feminist biology and white-tailed deer population control

The 1942 Disney movie Bambi follows the story of one white-tailed deer, from his birth through the birth of his offspring. An iconic film credited with changing public conversation in the United States about hunting, much has been written about the influence of Bambi on nature films and animal rights. The death of Bambi’s mother at the hands of a hunter is a critical plot point, and some scholars believe the film shaped US sentiments regarding the species.

White-tailed deer are one of the most beloved and despised wildlife species in the US. Populations have been closely monitored and managed since before 1900, when they were nearly extirpated. Yet by 1990, they were so populous as to be considered pests that threatened the economy and public health. They were blamed for millions of dollars in lost yield from crops and native plants, implicated in the rise of Lyme disease, and involved in over a million automobile accidents annually. The management paradigm thus focused on reducing populations. Though previously regulated mainly through hunting, post-Bambi control revolved around tracking and controlling female deer. While these controls have had some success, deer continue to be a nuisance. But re-evaluation of wildlife biology through the lens of feminist biology could make the control of this species more effective.

Feminist biology is a way of practicing science to help understand and parse social constructs that scientists may be projecting onto their subjects. In an interview, Dr. Caroline Van Sickle, an assistant professor of biological anthropology at A.T. Still University, defined feminist biology as “[o]bjective, well-tested, evidence based science that specifically focuses on avoiding biases related to sex or gender.” According to Van Sickle, “There are multiple examples in biology of research being influenced incorrectly by society's gender stereotypes — studies linking women with liking the color pink, men being good at a whole host of activities because they evolved to be hunters, and medical studies that assumed men and women have the same reaction to conditions like heart disease.” Dr. Van Sickle’s own research uses this approach to probe the evolution of Neanderthal birth, which was previously done by other researchers looking at male skeletons.  

The potential for applying feminist biology, however, is not limited to humans or hominids. Understanding and reflecting on bias can bring awareness throughout the experimental process. “I wasn’t particularly aware of the term feminist biology, but I think the general idea would seem common sense to many in wildlife biology,” says Dr. Anne Hilborn when I asked how the concept might apply to her research.

“We don't collar any of our cheetahs, so we find them opportunistically, which can lead to bias in what cheetahs we find,” she explains. “We rarely can study balanced numbers of male and female cheetahs, but almost all the work we do is broken down by sex. Male and female cheetahs have different strategies and pressures on them so except for population numbers we don't tend to make conclusions based on all cheetahs.”

All scientists, regardless of their own sex or gender, are influenced by representations and perceptions of gender in the human and non-human worlds — and this shapes their science. Research by David M. Marsh and Teresa J. Hanlon finds that scientists attribute differences in animal behavior differently based on their sex, or on their already-held views on sex differences in humans. Other scholars have explored whether scientists ignore observations that run counter to human gender norms.  

The case of reproductive control of deer shows how scientists may project these biases and how feminist biology provides an opportunity to intervene in these practices. Recent research indicates that hunters exhibit bias against lethal culling of female deer. Wildlife biologists and deer managers needed new and different kinds of information in order to support this non-lethal management paradigm. Programs like ear tag monitoring and “Deer Check Stations” monitored biometric and demographic information at a deer’s death. Biologists and managers now needed to understand deer reproduction in order to control it.

Those efforts focus on female white-tailed deer. One example is the development of vaginal implant transmitters (VIT). Researchers developed VITs to track pregnant deer remotely and to show where and when their young are born. The design was adapted from hormonal implants used in livestock to increase fertility. VITs don’t contain hormones; they house a temperature sensor that emits radio signals at set intervals. If the temperature drops, the radio signal changes. They are often paired with GPS collars; when a fawn is born, researchers are alerted to the time and place of the birth. The device is expelled with the fawn.

VITs enable rich data collection while minimizing logistical difficulties and stress on subjects. Yet VITs are not harmless. Robert A. Garrott and Richard M. Bartmann first tested VITs on mule deer in Northwest Colorado in 1982. Of 10 pregnant deer, two suffered severe vulvar trauma from the procedure and another three died from severe diarrhea. None of the fawns were recovered. A 1994 follow-up study by Jacob L. Bowman and Harry A. Jacobson using 16 white-tailed deer had better success. Subsequent studies refined the placement, housing, and success rate of locating VITs. But even after decades of tweaking, the process of placing VITs is not for the faint of heart. Pregnant deer are tracked, shot with a sedative dart, and the VIT is placed using a PVC pipe as a plunger-applicator.

VITs are just one technology in a broad suite of reproductive control methods focused solely on female deer. Wildlife biologists have attempted to modify techniques and technologies used in female humans for deer, ranging from daily oral contraceptives to steroid subcutaneous implants to immunocontraceptives. Progesterone and estrogen hormonal contraceptives have been tested on white-tailed deer since 1970, and porcine zona pellucida, a long-term immunocontraception vaccine, has also been experimentally used. Local municipalities with overabundant deer have tried tubal ligation and surgically removing ovaries, techniques that cost tens of thousands of dollars per subject.

The case of tubal ligations shows that the primary focus on female deer might be hindering larger control efforts. Tubal ligation did decrease pregnancies, but it altered doe reproductive cycles in ways that ended up attracting male deer. In an area trying to decrease deer populations, the decrease in fawns was outweighed by an 837% increase in adult male deer visitation to these areas. Moreover, deer are polygynous, meaning that a single male can impregnate multiple females each season. It would be too costly to sterilize every female in a population, but much more effective to sterilize males. This is a case in which focusing solely on female deer is inefficient.

A feminist biology approach to white-tailed deer management asks researchers to consider how the predominantly male gaze of the scientific establishment, the biases of researchers of all sexes and genders developed through cultural interactions with subjects like Bambi and his mom and how it impacts the lens through which they perform scientific research. Applying this approach to studying and managing white-tailed deer would not necessarily reject reproductive control of female deer outright. Instead, it invites researchers to consider non-lethal population control management strategies that do not disproportionately impact females. If we remove the focus on the control of the female deer, it is possible to see that other strategies involving males of the species could lead to even more effective controls.  

Further reading

Bruce T. Lauber, Barbara A. Knuth, James A. Tantillo, and Paul D. Curtis, “The Role of Ethical Judgments Related to Wildlife Fertility Control.” Society & Natural Resources 20, no. 2 (2007) 119-133.

Ralph Lutts, “The Trouble with Bambi: Walt Disney's Bambi and the American Vision of Nature.”  Forest & Conservation History 36, no. 4 (1992): 160-171.


 Image credit: Fawn lying on grass (Wikimedia Commons | CC BY-SA 3.0)