In the field of primatology, the ethics and implications of non-human primate field research have been receiving greater consideration in the past fifteen years. While non-human primate field research is a valuable tool because it increases our knowledge about our ancestors, it also creates an ethical conundrum from a biocentric perspective because of effects from the habituation process which is often used to obtain data. Habituation can prove hazardous to the welfare of non-human primate subjects as it can completely remove the fearful instinct to flee from human presence. I will begin by describing the habituation process and then explaining the effects from habituation which are of ethical concern, and then consider the various objections to the categorization of habituation as an unethical practice in field research. Finally, I will argue that I will utilizing full habituation in non-human primate field research is unethical as it compromises the welfare of its subjects and the legitimacy of the data collected.
Habituation is a critical method within field research which allows researchers to observe free-ranging non-human primates within a close range. For the purpose of this paper, habituation is defined by Rankin et al. (2009) as, “a behavioral response that results from repeated stimulation … and repeated applications of the stimulus results in decreased response.” In this case, stimulation refers to a human researcher repeatedly approaching a subject until the subject is desensitized to human presence. The essential goal of habituation is to have the subject recognize the researcher as a neutral entity within its own environment. This method is used for field research in order to track subjects, collect data while freely moving about, and conduct studies on individual subjects. Habituation can involve a group of researchers tracking down a group of non-human primate subjects and subjecting them to human exposure daily over an extended period of time ranging from under a month to as long as five years.
Habituation in a natural setting; people in close contact with gorillas (Gorilla gorilla). (Photo by: Ian Redmond, gorilla.wildlifedirect.org)
Another technique of habituation involves food provisioning, which can also serve to reduce fear of humans and further allow researchers to have closer contact to their non-human primate subjects. Williamson and Feistner (2003) establish food provisioning as, “use of artificial feeding as a positive incentive to tolerate human presence.” Food provisioning entails providing non-human primate subjects a sampling of preferred foods (such as fruits) which allows the researchers to observe the subjects as they feed and reduces the non-human primate’s fear of humans. Over time, as the food provisioning technique is used, the subjects become more comfortable with the researchers and offer better visual observations for researchers. Food provisioning serves as a convenient method for researchers to familiarize non-human primate subjects with human presence from researchers in order to collect data from an observational setting.
Because many non-human primates are fearful of humans, human presence is significant in a field research setting concerning successful completion of research. In gorillas (Gorilla gorilla berengei), habituation is particularly difficult as gorillas have extremely low population densities in environments which tend to be visually challenging due to climatic conditions (Doran-Sheehy 2007). Because of the conditions of the climate, it was imperative to habituate the subjects in order to facilitate better tracking for data collection. In 2001, Doran-Sheehy (2007) and her colleagues set out to habituate a group of gorillas at the Mondika Research Center in the Central African Republic and the Republic of Congo. The researchers habituated a group of gorillas by using a method which involved making no specific value-oriented action except for soft vocalizations to aid awareness of human presence. Over a period of 31 months, a majority of the tracked gorilla population was considered habituated for research purposes as the gorillas would not retreat from human presence.
For the example of the gorillas at the Mondika Research Center, and in many other cases in primatological field research, habituation was a necessary tool in order to conduct the study and collect data. In field research, when a non-human primate subject has not been exposed to human presence for long enough, the most common response by subjects is to flee and escape before researchers are able to collect data. Additionally, even if the group remains long enough for a researcher to collect data, the observing researcher might not be close enough to detect specific behavioral reactions critical to some studies that may last for only a few seconds such as lip smacking.
A western lowland gorilla (Gorilla gorilla gorilla). (Photo by: Rick Murphy - Primate Info Net)
While habituation can facilitate the collection of data from an observational perspective, it can also serve as an ethically problematic situation in field research. Habituation requires two specific traits in order for it to be successful. The first is that the habituation must have humans associated as a neutral element to the non-human primate subject’s environment. The second is that the non-human primate subject’s natural behavioral response of fleeing is removed or reduced in order to be able to get closer to the desired subject for, in field research purposes, data collection and observation. These two requirements alone make habituation an ethically questionable method in a biocentric perspective for research and for non-human primate welfare purposes.
Biocentrism is a perspective often utilized for environmental ethics, but can also be appropriate for non-human primate field research as subjects are a part of the environment. From a biocentric perspective, habituation can be perceived as an ethically problematic aspect. Biocentrism requires a “respect for the welfare and inherent worth of all organisms” (Derr and McNamara 2003). Thus, for field research using habituation methods to be considered ethical from a biocentric view, an action must consider the welfare of the non-human primate subject and respect its inherent worth within its environment. Although it might seem like researchers are compliant of this because they may be attempting to perform the research to cultivate respect for the non-human primate subjects, it does not follow necessarily that the field research undertaken to do so is necessarily biocentric. In order to illustrate how this might be the case, I point to examples of effects from habituation as to how habituation may not be an ethical method in terms of the requirements of biocentrism.
The purpose of habituation is to eventually have non-human primate subjects such as gorillas to regard human presence with a neutral association. However, by removing this fearful stimulation of humans and replacing it with a neutral association, gorillas become more susceptible to predation pressures from humans. In some cases, after some gorillas in the Democratic Republic of Congo and Uganda were habituated for field research, incidences of crop raiding behaviors from gorillas increased (Lee and Priston 2005). In these cases, gorillas were often eating crops that native farmers cultivated for subsistence purposes. Retaliation towards gorillas that eat the crops often results in death; an especially costly price for gorillas, which have been declining in population over the last 20 years (Harcourt and Stewart 1980; Robbins and Williamson 2008).
Rangers carrying the body of a deceased gorilla in Virunga National Park in 2007. (Photograph: WildLifeDirect via Guardian)
Because the crop-raiding behaviors which developed from habituation of less fearful gorillas were unintended from the researcher’s perspective, this particular example of non-human primate subjects demonstrates the significance of attempting to predict the side effects from research. Even though the researchers studying gorillas in their natural settings respected the intrinsic value of the primate subject, the effects from the researchers established an abnormal sense of security within the gorillas from the habituation method and made them susceptible to retaliation from the human population, as they had never received any negative reaction from the human researchers. By removing the natural fear stimuli from the gorillas, they felt less fear when going near crops established by the humans who were quick to retaliate against the non-human primates they perceived as pests. As a result, the welfare of the gorillas was significantly reduced for individual gorillas within groups. Therefore, the effects from habituation in terms of removing fear of humans are in violation of the welfare principle of biocentrism, suggesting that it is an ethically questionable method from this perspective.
Another problematic surrounding the ethics of habituation in field research is how habituation can play a role in disease transmission between non-human primate subjects and human researchers. By removing the fearful stimulus and changing the contact between humans and gorillas, there is a risk of increasing susceptibility to disease. Gorillas are particularly susceptible to respiratory diseases from humans as there was no prior exposure. In 1988 at Virunga National Park in the Democratic Republic of Congo, Uganda, and Rwanda, six female gorillas died and 81% of apes within the group showed clinical signs of a respiratory disease after a research group came to study the habituated apes (Woodford et al. 2002). What ultimately caused these apes to become ill was exposure to infected individuals within the research group. Although the researchers, again, may have had interests of the gorillas’ inherent worth at heart, they ultimately failed to respect the gorillas’ welfare by continuing research while infected. Because six of the gorillas died and a majority showed clinical signs of the disease, the lack of consideration in terms of physical health is a clear violation of respect of welfare.
A gorilla habituated for ecotourism purposes. (Photo by: Natl. Geographic Adventure)
While both risks of predation and disease risks increase because of habituation, there are still reasons as to why habituation is ethically permissible to human researchers. Although habituation was not used in the example of the gorillas in the Mondika Research Center, it has been used in other field research sites such as Jane Goodall’s site in the Gombe Stream National Park in Tanzania up until 2000. Like many other aspects of science, food provisioning is not without consequence, there are ways of mitigating the damage from the consequences thereof. One of the methods of reducing the negative impacts of habituation is to remove food provisioning from field research sites completely. By removing the food, non-human primate subjects are unable to make an association between humans and food resources; thus, making them less likely to go near crops in human territory. Another benefit of removing food provisioning is that the risk for disease transmission risk is reduced when neither humans nor other non-human primate subjects are handling the same food sources. However, while this does give greater consideration to the welfare of the non-human primate subjects, there are also other matters related to habituation which many argue on the behalf thereof.
A male silverback gorilla at the Milwaukee Zoo, "habituated" by human presence. (Photo by: A.V.S.)
One of the other significant arguments which has been posed for the potential resolution of the ethical problems of habituation is to not fully habituate the non-human primate subjects. Habituation is not a strict method with only one degree; there are varying levels of habituation. Non-human primate subjects can be semi-habituated to the degree in which subjects ignore human presence around half of the time. In these cases, human researchers can document observances while at the same time preserving a partial fear of humans to help reduce crop-raiding behaviors. Thus, researchers can maintain their research studies (albeit at half of the time of a fully habituated group), but also respect the welfare and intrinsic rights of the non-human primates by only semi-habituating groups.
In the case of the gorillas, I would not perceive the practice of full habituation as ethically permissible. First, while the habituation methods used did not involve food provisioning, they were tracking and most likely did contribute to stress levels for the gorillas over a 31-month period—thus, reducing the welfare of the gorilla troop. Secondly, by fully habituating these groups, the researchers were not respecting the intrinsic welfare or respect of the gorillas by altering their natural behavioral tendencies to fit their needs and therefore putting the gorillas at risk of predation and disease susceptibility. These effects can be removed over time if researchers are prohibited from taking part in research on that particular group, but this is unlikely to happen, as there are still data deficiencies in information about gorillas and other non-human primates. A better method might be to prohibit future habituation methods in other non-habituated gorilla groups in the same geographic range. As it stands, I do not find the methods undertaken by the Doran-Sheehy group of researchers to be considered ethically permissible.
From a biocentric perspective, full habituation is an ethically questionable method which I find to be ethically non-permissible. Although it can be used responsibly and for well-intentioned purposes of research studies, the side effects on the non-human primate subjects thereof remain long after the researchers have left the field site, often with significant consequences in the case of the gorillas. I believe that by prohibiting food provisioning and only semi-habituating non-human primate subjects, field research would be more biocentrically ethical in terms of the action of habituation and its after effects. Furthermore, if researchers only use sites where non-human primate subjects have been habituated, it would prevent consequences at a greater level as opposed to a specific population. Even if habituation is a necessary tool, it is one that can be used in moderation and by performing it responsibly and ethically.
Another method of helping gorillas who have been habituated is to donate to veterinarians willing to donate their time to the cause. Over at 1 of 750,Adam Moreze has a great offer for those wanting to help. For every $10+ you donate to the care of mountain gorillas, you “get one” in return. One being a limited edition print, of course! All proceeds (minus shipping) go toward the Mountain Gorilla Veterinary Project. It’d be a great and charitable gift for the great apes in your life!
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Woodford, M.H., Butynski, T.M. & W.B. Karesh (2002). Habituating the great apes: the disease risks. Oryx, 36(2): 153-160.
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