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| ARTICLE
Year : 2022 | Volume
: 20
| Issue : 1 | Page : 1-11
How Will the End of Bear Bile Farming in Vietnam Influence Consumer Choice?
Elizabeth O Davis1, Diogo Veríssimo2, Brian Crudge3, Son H Sam4, Dung T Cao4, Po V Ho4, Nhung T. H. Dang4, Tu D Nguyen4, Hien N Nguyen4, Trung T Cao4, Jenny A Glikman5
1 San Diego Zoo Wildlife Alliance, Escondido, California, USA
2 San Diego Zoo Wildlife Alliance, Escondido, California, USA; Department of Zoology, University of Oxford, Oxford, UK
3 Free the Bears, Luang Prabang, Lao PDR; Department of Natural Resources and Environmental Health, University of South-Eastern Norway, Bø, Nordland County, Norway
4 Vinh University, Thành Phồ Vinh, Nghệ An, Vietnam
5 San Diego Zoo Wildlife Alliance, Escondido, California, USA; Instituto de Estudios Sociales Avanzados, Cordoba, Spain
Correspondence Address:
Elizabeth O Davis
San Diego Zoo Wildlife Alliance, Escondido, California
USA
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/cs.cs_74_21
| Date of Submission | 19-May-2021 |
| Date of Acceptance | 19-Aug-2021 |
| Date of Web Publication | 18-Nov-2021 |
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 Abstract | | |
The Vietnamese Government committed to closing all bear farms in the country by 2022. Some researchers have expressed concerns that ending the commercial farming of bears, while demand for bear bile persists, could lead to increased hunting pressure on wild bear populations. In this article, we used mixed methods of questionnaires, Discrete Choice Experiments (DCEs), and interviews to investigate current consumer demand for bear bile in Vietnam, with a specific aim of understanding the potential for consumers to seek out wild bear bile. We sampled at seven areas across the country of Vietnam (total respondents = 2,463). We found low use of farmed and wild bear bile. Despite widespread belief in farmed and wild bear bile's efficacy, we found that individuals were apathetic about continuing to use bear bile. Coupled with a strong preference for using synthetic bear bile over wild and farmed bear bile found in the DCEs, we posit that bear bile consumers in Vietnam will be willing to use non animal-based products, including bear bile plant and Western medicine, to treat future ailments.
Keywords: choice experiment; specialized questioning techniques; Ursus thibetanus; Helarctos malayanus; wildlife farming
How to cite this article:
Davis EO, Veríssimo D, Crudge B, Sam SH, Cao DT, Ho PV, Dang NT, Nguyen TD, Nguyen HN, Cao TT, Glikman JA. How Will the End of Bear Bile Farming in Vietnam Influence Consumer Choice?. Conservat Soc 2022;20:1-11 |
How to cite this URL:
Davis EO, Veríssimo D, Crudge B, Sam SH, Cao DT, Ho PV, Dang NT, Nguyen TD, Nguyen HN, Cao TT, Glikman JA. How Will the End of Bear Bile Farming in Vietnam Influence Consumer Choice?. Conservat Soc [serial online] 2022 [cited 2023 May 29];20:1-11. Available from: https://www.conservationandsociety.org.in//text.asp?2022/20/1/1/330663 |
Abstract in Vietnamese http://bit.ly/31UPa82
| Introduction | |  |
Illegal trade in wildlife has been associated with the decline of multiple species and loss of biodiversity worldwide (Vié et al. 2009), particularly large-bodied mammals that are more vulnerable to overexploitation ('t Sas-Rolfes et al. 2019). Commercial farming can be an effective conservation strategy for certain species, providing sustainable and legal sources of products (Bulte and Damania 2005). However, for many species the sustainability of commercial wildlife farming is the subject of debate due to uncertainty around conservation outcomes (Crudge et al. 2018; Challender et al. 2019; Turvey et al. 2021).
The Asiatic black bear (Ursus thibetanus) is a CITES Appendix 1 listed species judged to be threatened by trade. The species is hunted throughout its range, in part to supply to the market for bear gallbladders and bear bile for use in traditional medicine across Asia (Foley et al. 2011; Burgess et al. 2014; Garshelis and Steinmetz 2020). Asiatic black bears produce relatively high concentrations of ursodeoxycholic acid (UDCA), the medicinal component of bear bile (Garshelis and Steinmetz 2020). Despite the widespread availability of herbal alternatives and synthetic UDCA, demand for natural bear bile persists, leading to the exploitation of this species (Garshelis and Steinmetz 2020). Although Asiatic black bears are the primary target for traditional medicine, sun bears (Helarctos malayanus) in Vietnam are also hunted for this purpose (Crudge et al. 2019), although there is currently no scientific evidence that sun bear bile has the same medicinal properties as Asiatic black bear bile.
Since the 1970s Asian bears have been kept in captivity for the purposes of bile extraction (Feng et al. 2009; Scotson et al. 2017; Crudge et al. 2018; Livingstone et al. 2018). Hunting continues, however, and populations across the species’ ranges are estimated to have declined by 30% over the past 30 years (Scotson et al. 2017; Garshelis and Steinmetz 2020). The conservation potential of commercial farming is dependent on consumers accepting the farmed product as a suitable substitute (Phelps et al. 2014). Research in China and Vietnam—the primary bear bile farming nations—suggests that there is a preference and willingness to pay more for wild bear bile than farmed (Drury 2009; Dutton et al. 2011). It is further suggested that the widespread availability of farmed bear bile may ultimately increase pressure on wild populations through a broadening of the customer base and an increase in non-traditional uses of the product (Drury 2009; Garshelis and Steinmetz 2020). Indeed, there is no published literature on consumer segmentation of bear bile users in Vietnam, e.g. use of wild and/or farmed bear bile based on income and/or status. However, Drury (2009) documented her sample of middle-class to upper-class Hanoians as using farmed bear bile, and the use of farmed bear bile was widespread in the urban samples of Davis et al. (2019). In both studies, there was a documented preference for wild bear bile, yet persistent use of farmed bear bile.
Following the introduction of legislation in Vietnam in 2005, prohibiting bile extraction and the restocking of farms with wild bears, the number of bear farms declined steadily mainly due to the poor husbandry conditions in which the bears are kept, which severely shorten bears’ natural lives (Crudge et al. 2018; Bando et al. 2019). It should be noted that although extraction and sale of bear bile was prohibited in Vietnam, it remained widely available (Willcox et al. 2016). Indeed, at its peak in 2006—the year after bile extraction was banned in Vietnam—the number of bears in farms in Vietnam was over 4,000 (Crudge et al. 2018). At the 2012 IUCN World Conservation Congress, members recommended the phasing-out of bear bile farming in four nations, including Vietnam, and a review of the situation in China (Garshelis and Scotson 2012). In China, where there are estimated to be >17,000 bears in bile farms, it is suggested that farming should continue in order to prevent an increase in poaching pressure to meet continued demand (Haikui and Zhi 2007). In contrast to China, where there is some evidence of captive breeding (Garshelis and Steinmetz 2020), in Vietnam captive breeding was negligible and most bile farms were stocked and restocked with wild bears (Crudge et al. 2018). In 2017 the government of Vietnam committed to phasing out bear bile farming over a five-year period (Animals Asia 2017). The Vietnamese Traditional Medicine Association also committed to practitioners no longer prescribing bear bile by 2020. It is currently reported that there are fewer than 400 bears remaining on bile farms in Vietnam (ENV 2020), while wild bear populations have been extirpated or are severely depressed in much of their remaining habitat throughout the country (Crudge et al. 2016).
Our objective in this study was to understand whether the reduced availability of farmed bear bile, and the eventual full closure of bear farms, could lead to a rise in demand for wild bear bile in Vietnam. To accomplish this objective, we used mixed methods including questionnaires, DCEs, specialized questioning techniques (SQTs), and qualitative interviews, to gain a broad, deep, and accurate understanding of bear bile use currently across Vietnam. While DCEs explore preferences, which do not directly equal “demand”, they are a part of the “purchasing process” that is the basic structure of demand (Veríssimo and Wan 2019). Building on the structure of the “decision-making process” that constitutes demand, the demand for wildlife also encompasses various influential factors, such as social norms, age, beliefs, etc. (Veríssimo et al. 2020). Thus, the mixed methods used in this paper reflect established literature in their utility in understanding these various aspects of demand (Davis et al. 2020a, Hinsley et al. 2021).
| Materials and Methods | | |
Study areas
To gain a wide picture of bear bile use and complexity in Vietnam, we chose seven study areas that we believed encapsulated different and important attributes of Vietnam: whether bear farms were in the area at the time of sampling, whether wild bear populations were likely to be near, and where the areas were located geographically in Vietnam, i.e. north, centre, south [Figure 1]. These attributes were chosen because they could potentially influence how bear bile is consumed, and in what quantity it is consumed in an area (examples of attributes can be found in Supplementary Material I). | Figure 1: Map of the study areas in Vietnam (created by Jenna Stacy-Dawes)
Click here to view |
Study participants
We investigated the use of bear bile among different ethnic groups, including the dominant Kinh ethnic group, as well as the Co Tu, the Hmong, the Dao, and the Thai. We conducted surveys and interviews in both urban areas (e.g. Da Nang City (Central Vietnam)) and in rural areas (e.g. Lào Cai Province (Northern Vietnam)).
Survey instrument design
The survey instrument was broken into three sections. Section A was composed of closed-ended questions, including the SQT of Unmatched Count Technique (UCT), while Section B was the DCE. The DCE followed the methods of Veríssimo et al. (2014a), Hinsley et al. (2015), and others who have explored similar issues within conservation. In Supplementary Material I we explain the SQTs and DCEs in greater detail.
Section C included direct questions about use of wildlife products, synthetic bear bile, and bear bile plant in the past twelve months. In the survey, the project team ensured that the definitions of each product were clear. Wild animal products were translated as “wild” (i.e. not farmed, not processed in a lab), while synthetic bear bile was translated to mean chemically-made bear bile, which is known to most Vietnamese as an accessible product available in local pharmacies. 'Bear bile plant’ is well known to be a specific organic plant product in Vietnam and is a popular form of herbal medicine (Davis et al. 2019a).
Section C of the survey also included the qualitative component, and the SQT of Nominative Technique (NT). Specific details of each section can be found in Supplementary Material I, with descriptions of each SQT. Socio-demographic questions were split between the beginning and end of the instrument; more sensitive demographics such as monthly income were placed at the end. In addition, the research team was actively encouraged and specifically trained to write down additional notes about the context of the interview, e.g. if other individuals were present, as well as additional information that came up during broader discussions during the surveys, and whether they believed the respondent was trustworthy. This information was used to assess the reliability of the overall dataset.
Sampling method
Quantitative sections
In each study area, teams of two research assistants walked different streets each day and surveyed every fourth household on their left. This sampling was used due to the scattered distribution of households and to reach our target sample size in rural areas. One person in each household was surveyed, and all respondents were over 18. Male/female respondents were alternated.
Qualitative interviews
Respondents who directly reported to ever using bear bile were asked whether they would like to participate in a qualitative interview following the quantitative section, which would ask them more detailed questions about their use. The research assistants attempted to gain an equal distribution of men and women; however, as women are known to underreport behaviour that could be considered sensitive and/or undesirable (Durant et al. 2002), women were underrepresented in the qualitative interviews in some sites. Due to time constraints, research assistants stopped interviewing bear bile users once they reached a threshold of approximately 30 interviews in each study area.
Choice experiments
The choice experiment was conducted within the main body of the questionnaire; however, respondents were randomly assigned to one of four choice blocks (Supplementary Material I) to investigate two potential scenarios regarding bear bile purchase. These two scenarios were: 1) buying medicine for a family member to treat a bruise and 2) buying medicine to treat a sprained ankle. Scenario 1 was selected according to the prior research and experience of the author team, who found that individuals may buy and/or give bear bile to bruised family members (Davis et al. 2019a, 2020a,b and Ho et al. forthcoming). Scenario 2 was selected as an alternative to Scenario 1 being an individual purchase for their own ailment, and for being a comparative ailment in severity and treatment with bear bile in Vietnam (Davis et al. 2019a). Both ailments were selected to be comparatively minor because bear bile is generally used for comparatively minor ailments, particularly in Vietnam (Davis et al. 2019a). Porcupine stomach was included in the choice experiment as a comparable wildlife product: (1) because research in Laos and Cambodia (Davis 2020; Davis and Glikman 2020), and anecdotal evidence in Vietnam, demonstrated that porcupine stomach is used in traditional medicine to treat similar ailments as bear bile/gallbladder; and (2) because porcupines are available in Vietnam in both farmed and wild forms (Brooks et al. 2010).
Each research assistant had an anonymous ID sheet that also had a corresponding choice experiment scenario block. This was then stratified by the known Vietnamese population proportions of age and gender (The World Factbook 2021) and systematically and randomly assigned for each person, e.g. a respondent would be assigned ID #1785 and Scenario 1: Block D, Scenario 2: Block A. The ID was linked to the scenario and block simply as a way for the enumerators to easily assign the different blocks to each respondent. Blocks were assigned based on probability, with 25% of the sample assigned to each block.
Data analysis
Quantitative analysis
Data was entered into Google Forms by the CERD research team after completing each site, and checked periodically by the CERD team, as well as by the lead author. We analysed all data using R (R Core Team 2020). Generally, we calculated confidence intervals using the standard equation; in the case of the UCT double distribution confidence intervals, we used a function we wrote for the purpose in R (Supplementary Material VI). Confidence intervals were used in place of null hypothesis significance tests, as confidence intervals inherently indicate whether distributions overlap (i.e., statistically insignificant difference) or do not overlap (i.e. statistically significant difference) (Kline 2004); therefore, they provide “statistical clarity” compared to commonly used (and misused) null hypothesis significance tests (Dushoff et al. 2019).
We used R to calculate descriptive statistics, e.g. percentage of individuals who directly admitted to using bear bile, and relied on the dplyr package for much of this descriptive analysis (Wickham et al. 2020). For the creation of the demographics table (Supplementary Material VII) we used the package gt (Iannone et al. 2020). We calculated the SQTs using the formulas found in Davis et al. (2019b, 2020c).
Choice experiments
We analysed the data using LIMDEP and NLOGIT 4.0. We assessed preferences of respondents using Random Parameter Logit (RPL). This model type allows for the investigating of how individual respondent characteristics impact preferences, which can help us better understand heterogeneity amongst respondents. This is accomplished through specifically investigating the variance and the mean coefficient. For example, for an attribute to be meaningless, both the mean coefficient and the variance must be “insignificantly different” from zero; if the variance is significant, the researcher can only infer that a “diversity of preferences” exist within the sample (Rigby and Burton, 2003).
Qualitative analysis
The qualitative interviews were translated from Vietnamese into English by a member of the CERD staff, and analysed by the lead author following the standard process of coding and grouping codes into generalisable themes (Bernard 2017). The themes found in the qualitative data were grouped around existing themes that the author team had chosen to investigate, such as behavioural intentions around bear bile farming. This was done per study area, in recognition of the diversity of contexts within Vietnam. This recognition was founded both on a personal experience of Vietnam (e.g., the Vietnamese author team's lived experiences), and quantitative data, which showed clear differences across study areas.
| Results | | |
Demographics
Quantitative interviews were conducted with a total of 2,463 respondents in Lào Cai (n = 383), Hai Phong (n = 402), Nghệ An (n = 435), Da Nang (n = 194), Quảng Nam (n = 200), Tây Ninh (n = 423), and Đồng Nai (n = 426). The sample was predominantly male (54%), with a mean age of 42. Most of the sample had lived the majority of their lives within the study area, and had high school/secondary school (in Vietnamese, Trung học phổ thông (THPT)) as their highest level of education. The sample was primarily Kinh, and the most common religion was ancestor spirit worship. Most of the sample stated that their income was between 0 to 10 million Vietnam Dong a month, equivalent to ca. 0 USD to 432.6 USD. Further details on demographics of the full sample can be found in Table S.3, Supplementary Material VII.
Qualitative interviews were conducted with a subsample of 173 respondents of the full sample of 2,463 respondents; these respondents were sampled from individuals who reported having used bear bile. We interviewed 32 self-stated bear bile consumers in Lào Cai, 25 in Hai Phong, 36 in Nghệ An, 27 in Quảng Nam/Da Nang (treated as one site for the interviews, due to their close proximity), 25 in Tây Ninh, and 28 in Đồng Nai. The sample was predominantly male (79%).
Estimates of bear bile use prevalence
Direct reporting of bear bile use in the past twelve months
Of the 2,463 respondents, 771 (31.3%) stated that they had used bear bile/gallbladder in their lifetime, and of those users, 46.3% (357/771) had used both farmed and wild bear bile. Of those users, only 4.5% (16/357) (0.7% of the full sample of n = 2,463) directly reported using both wild and farmed bear bile in the past twelve months.
A small percentage (5%) of respondents stated that they had consumed farmed bear bile in the past twelve months (CI: 4.4%–6.1%, SE: 0.5%, n = 129/2,463), while 3.8% of the respondents stated that they had consumed synthetic bear bile in the past twelve months (CI: 3%–4.6%, SE: 0.4%, n = 93/2,463). Both of these estimates were three times higher than the number of individuals who stated that they had directly consumed wild bile in the past twelve months, 0.9% (CI: 0.5%–1.3%, SE: 0.2%, n = 22/2,463).
Direct estimates of bear bile, porcupine stomach, and bear bile plant use, in the past twelve months
Across all sites, except from Nghệ An, no respondents reported using wild bear bile in the past twelve months (total n = 2,463, Table S.4 in Supplementary Material VII). In Nghệ An, 5% of respondents (3.1%–7.3%) admitted to having used wild bear bile. However, it was more common for respondents to admit to using farmed bear bile. In Nghệ An, 22.9% (18.9%–26.8%) admitted to using farmed bear bile in the past twelve months, which did not overlap with the 95% confidence interval for admitting to using wild bear bile (Table S.4). In Quảng Nam and Da Nang, which are closely neighbouring areas to one another, no respondents admitted to using farmed bear bile.
Direct reporting of synthetic bear bile use was lower than reporting of farmed bear bile use in every province apart from Tây Ninh. In Nghệ An, 14.5% (11.2%–17.9%) of respondents admitted to using synthetic bear bile, which was significantly lower than admittance of farmed bear bile use in the area. In Lào Cai, Da Nang, and Quảng Nam, no respondents reported using synthetic bear bile (Table S.4).
Respondents reported using bear bile plants in all of the study areas, with an overall estimate of 15.7% (14.3%–17.2%). The highest use was in Nghệ An and the lowest in Hai Phong. Of the sample, 3.1% (2.4%–3.7%) of respondents directly admitted to using porcupine stomach, with the highest admittance in Nghệ An, and the lowest equally in Da Nang and Hai Phong, with one person in each site admitting that they had used porcupine stomach, and confidence intervals overlapping with zero (Table S.4).
UCT estimates
Prevalence estimates of farmed bear bile, wild bear bile, and porcupine stomach use all overlapped with 0%, across the sample. The prevalence estimates of farmed bear bile use across the 2,463 respondents was -1.8% (-8.5%–4.9%). For wild bear bile, the estimate was 0.3% (-6.8%–7.4%), and for porcupine stomach the estimate was 3.2% (-4.2%–10.6%).
Most of the UCT prevalence estimates for wild bear bile (5 out of 7 study areas) and farmed bear bile (4 study areas) were negative per study area, while slightly less than half were negative for porcupine stomach (3 study areas) (Figure S.2, Supplementary Material VII). All overlapped with 0%, apart from in Nghệ An. In Nghệ An, respondents were found to use porcupine stomach significantly over 0 (24%, 3.1%–44.9%).
NT estimates
When using NT, the highest estimated prevalence of all types of bear bile consumption in the past twelve months was found in Nghệ An, with an estimated prevalence of 33.8% (29.8%–37.8%). The lowest estimated prevalence was found in Quảng Nam, at 0%. The other study areas were all significantly lower than Nghệ An, with the highest prevalence estimated to be 1.7% in Đồng Nai (0.8%–2.6%), followed by Da Nang at 1.5% (0.1%–2.9%), Tây Ninh at 1% (0.3%–1.7%), Hai Phong at 0.8% (0.1%–1.5%), and finally Lào Cai at 0.2% (-0.2%–0.7%), which overlapped with 0%.
Beliefs
More than 50% of respondents believed that, “It is easy to find places to buy bear bile/gallbladder”, in Hai Phong, Lào Cai, Nghệ An, and Đồng Nai. Da Nang was the most equivocal about bear bile/gallbladder's accessibility, while in Tây Ninh respondents were least likely to agree that bear bile/gallbladder was easily accessible.
Respondents in Nghệ An were most likely to believe that farmed bear bile has medicinal value, while respondents in Lào Cai were least likely to agree with that statement. Da Nang and Quảng Nam followed Lào Cai respondents with less strong beliefs in farmed bear bile having medicinal value, while respondents in Đồng Nai and Tây Ninh were comparatively more likely to believe that farmed bear bile has medicinal value. Finally, respondents in Hai Phong were equivocal about the medicinal value of farmed bear bile.
Respondents in Lào Cai, Nghệ An, and Đồng Nai were most likely to believe that wild bear bile has medicinal value, with Lào Cai having the strongest agreement with the statement. Respondents in Quảng Nam and Da Nang were most equivocal about the statement that “wild bear bile has medicinal value”, while respondents in Hai Phong were most likely to disagree with that statement, compared to other study areas. Nearly half of all respondents in Tây Ninh agreed with the statement, but another half of respondents were split between feeling equivocal, and disagreeing with the statement.
Choice experiments
Buying medicine for a family member with a bruise
Regarding Scenario 1, our results (Supplementary Material VIII) show that respondents preferred synthetic bear bile followed by natural (wild or farmed) bear bile. Porcupine stomach was avoided by most consumers, with many also preferring not to choose any of the alternatives provided. In terms of natural (not synthetic) bear bile, respondents preferred wild sourced bear gallbladder at the lowest possible price. We also investigated in more detail potential heterogeneity around preferences, in particular for wild versus farmed bear bile, and potential differences between users and non-users. In terms of location, respondents from Nghệ An Province, as well as those that identified as male, were more likely to prefer wild sourced bear bile. However, respondents from the Kinh ethnicity, as well as those with higher levels of education, preferred giving bile from farmed bears to bruised family members. We found no differences in choice between self-reported users and non-users.
Buying medicine to treat a sprained ankle
Regarding Scenario 2, our results (Supplementary Material VIII) align with those above, with respondents preferring synthetic bear bile followed by wild bear bile. Porcupine stomach was avoided by most consumers, with many preferring not to choose at all. In terms of natural bear bile, respondents preferred bear gallbladder at the lowest price, but the source was not important. We also investigated in more detail potential heterogeneity around preferences, in particular for wild versus farmed bear bile and potential differences between users and non-users. In terms of location, respondents from Nghệ An Province, as well as younger respondents and those respondents who believed primarily in ancestor spirits, were more likely to prefer wild sourced bear bile. However, respondents from the Kinh ethnicity, as well as those with higher levels of education, preferred bile from farmed bears. We found no differences in preferences between self-reported users and non-users.
Qualitative results
The qualitative results of our study confirmed the research team's experience in this field that bear bile is purchased for two primary groups: one's family members and/or close friends, and for oneself. We found that in every study area, except the northern study areas of Lào Cai and Hai Phong, interviewed bear bile consumers were roughly equally split in whether they had been given bear bile, or purchased it themselves. In Lào Cai and Hai Phong, a number of respondents cited having drunk bear bile socially; although social bear bile consumption occurred in the other study areas as well, the extent was more pronounced in both of these areas. Social bear bile consumption was generally male-dominated in our sample, yet a young woman in southern Vietnam did describe having been invited to drink bear bile alcohol:
The first time [I used] bear bile was in university [about 6 years ago], a friend invited to drink bear bile alcohol.
(—26-year-old female, Bachelor's degree, Kinh, Tây Ninh)
Another woman (64-year-old, secondary school, Kinh, Nghệ An) who traded bear bile and other wildlife products described drinking bear bile with her clients, possibly as a strategy to both encourage clients to purchase more of the product, and to affirm the quality of the product.
The way bear bile was stated to be used varied across Vietnam, although use was cited to be predominantly for medicinal purposes and/or social drinking. Use was often pluralistic, with individuals using bear bile for medicinal purposes, social drinking, and to build social capital (e.g., through giving it to others), or any combination of the three. This is well-illustrated below:
[I] use for drinking alcohol with counterparts or customers, gift to counterparts, [and] rub on [my] skin.
(—33-year-old male, PhD, Kinh, Nghệ An)
In Tây Ninh, Nghệ An, Hai Phong, and Lào Cai bear bile for social drinking was the predominant situation described, although predominant here generally means that it was only used for this purpose by a little over half of the sample. Only in Quảng Nam and Đồng Nai was bear bile used more generally for medicinal purposes.
Bear bile for medicinal purposes fell into four categories. Predominantly, it was used for treating severe bruises, such as those resulting from traffic accidents. Secondarily, it was used to treat general joint pain. Thirdly, it was used to treat stomach aches, when taken in some warm water. Fourthly, bear bile was used for postpartum treatment by women of the Thai and Hmong in Lào Cai Province, near the border of China.
We found that the use of bear bile could be passive—e.g., given to an individual after an accident, or active—e.g., where the individual sought bear bile to use. Two examples are given below, of these different types of uses:
[I] use [bear bile] a lot of times, because it's based on [my] job: Drinking alcohol and taking as a gift. (Passive)
(—46-year-old male, Bachelor's degree, Kinh, Nghệ An)
[I] ask my friends to buy [farmed] bear bile in the hometown, they ship by car, [and] can receive after a week of ordering (buy 50cc bear bile costing 3 million dong [~130 USD] each time). (Active)
(—47-year-old male, Business person, Kinh, Hai Phong)
In the first anecdote, the individual notes that drinking bear bile was a passive part of the job, while the second anecdote describes an active process where the user was seeking out bear bile. However, we found general apathy about the decline of bear bile use in Vietnam. For example, the individual who gave the anecdote about the active purchase of bear bile stated, “won't use bear bile anymore” when asked what he would do after bear farms are gone in Vietnam. This sentiment was shared across sites, e.g., “I don't use much bile anyway” (57-year-old Kinh male, Quảng Nam). We did record opposing sentiments, with sadness expressed over the perceived loss of an effective medicine (”No medicine can cure bruises as fast as bear bile”—36-year-old woman, Bachelor's degree, Kinh, Đồng Nai). Only a few individuals expressed hostility towards the government's actions to end bear farming, e.g., a man from Nghệ An who stated:
Don't care about prohibition. If needed, there would still [be] bear bile. The government can ban all the bear farms.
(—33-year-old, Kinh, Bachelor's degree)
Respondents were generally not explicit about where they obtained the bile they gave to relatives. For e.g., one respondent in Lào Cai (43-year-old college-educated male, Kinh) said that he “gave to family members”. Previously, he had stated that he had been given it as a gift by “local people” (i.e., people living in rural areas), with the implication that the bile was likely from wild bears. Respondents in Lào Cai generally were not aware of bear farms in the area (72%) or were certain that none existed (28%). Indeed, one individual in Lào Cai (43-year-old male, Bachelor's degree, Kinh) said that he had sought out farmed bear bile in Nghệ An, ~572 km south, after getting a taste for bear bile when given it by a friend for the first time.
The receivers of bear bile, i.e. bruised family members, in our choice experiment scenario, were generally unaware where the bile had come from. Said one respondent in Quảng Nam:
[I] was given 1 cc of bear bile by a relative for rubbing, didn't know [if] it was wild or farmed bear bile ([and] can't remember when).
(—57-year-old Kinh male, secondary school)
Another in Đồng Nai described the gift of a friend rather than a relative:
The last time using bear bile was after an accident (3 years ago), [I] had big bruises on legs and face. Doctor gave medication but it healed slowly and traditional herbs [as well]. A neighbour visited and brought alcohol bear bile for rubbing.
(—55-year-old Kinh female, college)
No bear bile consumers interviewed explicitly mentioned using synthetic bear bile to treat bruises, in any study area, despite a question that explicitly asked where the individuals had obtained the bile from. Instead, individuals stated that when they purchased the bile themselves, it was generally from a friend or a bear farm, with the implication that they were seeking out trustworthy vendors of farmed or wild bile from which to purchase bear bile. However, some respondents did state that they bought bear bile at a shop, which could imply that those individuals were purchasing synthetic bear bile from a pharmacy; equally, it could imply that farmed or wild bear bile was for sale at a pharmacy or at other brick and mortar shops.
| Discussion | | |
Current use of bear bile
With the decline of bear bile farming in Vietnam, there is concern among conservationists that some committed users will seek out wild bear bile and place pressure on beleaguered bear populations (Crudge et al. 2018). Indeed, this is one argument used to support the continuation of bear bile farming in China (Garshelis and Steinmetz 2020). Here, we showed that desire for wild bear bile is unlikely to result in increased bear hunting pressure in Vietnam. Bile farming has declined over a 15-year period (Crudge et al. 2018), and a desire for wild bear bile was found only in Nghệ An, Central Vietnam, where the highest levels of bear bile consumption currently occur (22.9% (18.9%–26.8%)). In our six other study areas, we found a strong stated preference through the DCE for synthetic bear bile over any other alternative. Preference patterns were not influenced by past consumption, meaning that previous users of wild and/or farmed bear bile were equally likely to choose to use synthetic bear bile. However, the coefficient in Scenario 1 (”buying medicine for a family member who has a bruise”) for price was smaller than for source, which suggested that source overrode price for this particular scenario, further indicating that source does matter in some situations. Nonetheless, the DCEs broadly suggest that wild bile is increasingly niche and phasing out farming is not likely to bring a resurgence of wild bear bile use. This is particularly noteworthy in light of the belief in wild bear bile's medicinal efficacy found in over 50% of the area's sample in Lào Cai, Nghệ An, and Đồng Nai, and approaching 50% in Hai Phong and Tây Ninh [Figure 2]. | Figure 2: Belief statements about availability of bear bile, and medicinal efficacy for farmed and wild bear bile (total n = 2,463)
Click here to view |
We found that only 0.7% of the full sample (16/2,463) admitting to using both products within the last twelve months. Of both products, farmed bear bile was used more often than any other bile option. This may be because farmed bear bile is still fairly accessible in certain areas, e.g., in Nghệ An where bile farms persist. Indeed, bear bile/gallbladder was generally believed to be accessible, by respondents across study areas, with over 50% of the sample thinking it was easily accessible in four out of our seven study areas (Hai Phong, Lào Cai, Nghệ An, and Đồng Nai), and approaching 50% in Tây Ninh [Figure 2]. Across the sample, respondents did not mention significant barriers to obtaining bear bile, and instead would mention having been given it by a friend, having purchased the bile alcohol at a restaurant, having it at an acquaintance's house, and other casual situations. As a contributing factor, we found that farmed bear bile largely mirrored wild bear bile in the belief in its efficacy, across study areas [Figure 2]. With wild bear bile, it was only in Da Nang and Quảng Nam that respondents largely disagreed (or did not know enough to state a belief) that farmed bear bile has medicinal efficacy.
Although no respondents in Quảng Nam, Central Vietnam directly admitted to having used bear bile in the twelve months before they were interviewed, lifetime users of bear bile in Quảng Nam were more likely to admit to using bear bile for medicinal purposes, compared to more predominantly social bear bile alcohol drinking areas such as Hai Phong, Northern Vietnam. Possibly, this could be due to a gender bias—alcohol consumption in Vietnam tends to be a male-dominated act (Drury 2011; Lincoln 2016), and very few women were interviewed about their use in areas such as Hai Phong where bear bile alcohol consumption was logged more frequently. Although at least two women were comfortable admitting to having used bear bile alcohol for social drinking, others may have felt uncomfortable admitting to the (illegal) act in light of the greater social pressure women feel to present themselves favourably, worldwide (Fisher 2013; Klein et al. 2019; Moran et al. 2018). Importantly, one of the women interviewed not only consumed bear bile alcohol socially, but had also traded wildlife throughout Vietnam, until she was caught. Her experience supports prior work that has shown that women can and are important in facilitating and perpetuating wildlife trade, although they are often overlooked in wildlife trade research and discourse (Agu and Gore 2020). In rural areas worldwide, women often occupy the role of 'trader', which means they are perfectly suited to traffic wild products that their male partners and kin may poach (Agu and Gore 2020). Moreover, emerging research has shown that women can be primary consumer groups for some wildlife products, and in certain contexts (Davis et al. 2020b; Doughty et al. 2021).
One possible explanation for the high stated use of bear bile in Nghệ An, Central Vietnam is due to the legacy of bear bile farming in the region (Crudge et al. 2018). This accessibility to bear bile may have ingrained the practice within the community, even as bear farms are increasingly shut down in the province (T. Cao, pers. obs.). However, Hai Phong in northern Vietnam had (and has) a similar number of bear farms (Crudge et al. 2018), but according to our results has low bear bile consumption. Why Nghệ An specifically has greater consumption of bear bile is an opportunity for further research, grounded in qualitative, exploratory methods.
Consumer preferences
We found a strong preference for synthetic bear bile over alternatives within the DCE. This result is somewhat surprising in light of our other finding that there was low actual consumption of synthetic bear bile, across study areas. Additionally, our qualitative results illustrated that there are persisting contexts of bear bile consumption where synthetic bear bile use is theoretically unlikely, such as the socialised consumption of bear bile alcohol, which prior research has shown tends to consist of wild or farmed liquid bile (Drury 2011). While our qualitative interviews did not uncover a preference for synthetic bear bile, it should be noted that those results come from a sub-sample of self-reported consumers, which is not directly comparable.
Choice preferences may also reflect how opportunistic bear bile consumption is in Vietnam. Although our qualitative results did show that bear bile consumption can be an active choice, these results were largely confined to Quảng Nam, where use was more predominantly medicinal; respondents in our other study areas largely had received bile opportunistically either when given it following an accident, or when socially drinking. However, it is worth noting that some respondents, after opportunistically receiving bear bile, then actively sought bear bile out for continued consumption following their initial consumption 'event'. Nonetheless, considering that source was not found to be important in one DCE scenario (Buying medicine for a family member with a bruise), and a found, general lack of strong preference for natural bile (wild or farmed), it is unlikely that many Vietnamese are committed to natural bear bile. Furthermore, this is supported by our finding that respondents were largely apathetic about the Government of Vietnam's goals to eliminate bear farming, giving responses such as “don't really care” and “just won't use [bear bile]”.
We found that approximately 16% of our sample had used bear bile plant, which was the highest overall estimate of use of a particular product (compared to e.g., farmed bear bile, at 5% of the sample). Even before bear bile farms began closing, the Vietnamese government was encouraging the use of herbal traditional medicines as a means of increasing 'self-reliance’ within rural communities (Naono 2014). Also, as bear farming's popularity has waned, bear-focused NGOs have been campaigning to encourage the use of herbal alternatives, such as bear bile plant, instead of bear bile (Animals Asia 2018). However, while it may be tempting to argue that bear bile plant can be a natural and seamless replacement for bear bile, preliminary research in Vietnam has shown that bear bile plant may be perceived as less effective compared to bear bile (Davis et al. 2019a).
Limitations
The SQTs employed in this study did not seem to have an effect in overcoming biases, possibly due to deceit in answering the SQTs (Davis et al. 2019b). However, the results from the qualitative interviews, and the research team's own experience in Vietnam, has shown that despite its illegality, bear bile use is fairly open and normalised. It is therefore unlikely that there are any strong biases precluding honest answers. Another explanation for the poor SQT results could be the experiences of the research team, who found that individuals preferred being interviewed over being surveyed. Respondents were more likely to find the survey to be too long and “boring”, which impacted their desire to answer every question, and to answer the questions accurately. Consequently, the respondents may not have been attempting to actively deceive the researchers, but a lack of attention and buy-in may have caused inaccurate responses to be given.
A limitation of this study is that 'bear bile plant’ was not offered as one of the possible alternatives in the choice experiment, despite consistent use of bear bile plant across the sample. This choice was made for three reasons. One, porcupine farming in Vietnam is a conservation concern (Brooks et al. 2010) and two, DCEs can only accommodate a limited number of attributes and levels before they put too much cognitive strain on respondents which can lead to lower quality data (Caussade et al. 2005). Finally, animal medicinal products can occupy a ’ 'spiritual’ and supernatural liminal space that plant medicinal products do not enter (Alves and Alves 2011).
Another limitation of our study is the lack of qualitative insight into bear bile consumption by women. Likely due to the social stigma women feel about admitting to sensitive behaviours that may be illegal and/or socially undesirable (Durant et al. 2002), women were underrepresented in our qualitative interviews. This may be why we found more use of bear bile alcohol in social/business settings in certain study areas, such as Hai Phong, and could also explain the lack of contextual evidence regarding the use of synthetic bear bile. An avenue for fruitful future research in Vietnam, therefore, could be a qualitative study of bear bile consumption by women.
| Conclusion | | |
It's unlikely that there will be greater consumption of wild bear bile in Vietnam. This is important in light of the documented and continuing debates centred around the farming of bears that argue that a loss of farmed bear bile may mean an increase in demand for wild bear bile. Instead, we show that a decline in farmed bear bile availability can simply mean that consumers shift towards products that are believed to have similar benefits, and that are cheap and easy to acquire, such as synthetic bear bile and bear bile plant. However, we note that consumer preferences are highly complex, and substitutes for unsustainable and/or illegal animal medical products are subject to the same complexities. Consumer research in China and other bear bile farming nations will determine if there is potential to phase out the practice of bear bile farming without risking a substantial increase in hunting pressure. As with any conservation effort, attempts to market bear bile substitutes should be spatially-unique and reflective of the local, documented consumer preferences.
Supplementary material can be accessed at: https://bit.ly/2YSm87t
Author contribution statement
Davis, E. conceived and designed the study; trained the research team; analysed the data; drafted the manuscript; and did a critical revision of the manuscript. Veríssimo, D. designed the study; analysed the data and did a critical revision of the manuscript. Crudge, B. designed the study; trained the research team and did a critical revision of the manuscript. Sam H. Son was involved with data collection and the critical revision of the manuscript. Cao T. Dung was involved with data collection and the critical revision of the manuscript. Ho V. Po was involved with data collection and the critical revision of the manuscript. Dang T. H. Nhung was involved with data collection and the critical revision of the manuscript. Nguyen D. Tu was involved with data collection and the critical revision of the manuscript. Nguyen N. Hien was involved with data collection and the critical revision of the manuscript. Cao T. Trung assisted with the design of the study; trained the research team and did a critical revision of the manuscript.
Glikman, J.A. conceived and designed the study and did a critical revision of the manuscript.
Acknowledgements
This work could not have happened without the skills and expertise of the translators, Ms. Vu Phuong Hoa and Ms. Ho Ha My. This work was made possible with the support of the Government of Vietnam, who granted permission for the project to be conducted. The Government of Vietnam also gave essential support to one of their educational arms, Tr'ò'ng Đại Học Vinh (Vinh University), in conservation efforts. We also gratefully acknowledge the insights of Prof. Quang and Prof. Hoi, as well as the assistance of Drs. Châu and Liên, and Ms. Lim Thona in the training process.
Declaration of competing/conflicting interests
E.O. Davis works for the San Diego Zoo Wildlife Alliance (SDZWA), a global conservation organisation. B. Crudge works for Free the Bears Fund, Inc., a bear rescue and conservation organisation.
Financial disclosures
This research was supported by SDZWA's postdoctoral program; no other funding was received.
Research ethics approval
Every respondent was assured of their anonymity and the confidentiality of the survey and told that they could drop out of the interview at any point, and for any reason. Every interview was anonymised, to ensure participant confidentiality. This project obtained ethical approval from the Miami University of Ohio Institutional Review Board #02106e, and permission for conducting the work was granted by both the Government of Vietnam, and specific provincial governments in Vietnam.
Data availability
The data is not accessible due to privacy restrictions.
Preprint archiving
The preprint of this article can be found here: https://osf.io/preprints/socarxiv/quyf2/
| References | | |
| 1. | Agu, H.U. and M.L. Gore. 2020. Women in wildlife trafficking in Africa: a synthesis of literature. Global Ecology and Conservation 23: e01166.  |
| 2. | Alves, R.R. and H.N. Alves. 2011. The faunal drugstore: animal-based remedies used in traditional medicines in Latin America. Journal of ethnobiology and ethnomedicine 7(1): 1–43. |
| 3. | |
| 4. | |
| 5. | Bando, M.K.H., O.L. Nelson, C. Kogan et al. 2019. Metabolic derangements and reduced survival of bile-extracted Asiatic black bears (Ursus thibetanus). BMC veterinary research 15(1): 1–16. |
| 6. | Bernard, H.R. 2017. Research methods in anthropology: Qualitative and quantitative approaches. Rowman & Littlefield. |
| 7. | Brooks, E.G., S.I. Roberton, and D.J. Bell. 2010. The conservation impact of commercial wildlife farming of porcupines in Vietnam. Biological Conservation 143(11): 2808–2814. |
| 8. | Bulte, E.H. and R. Damania. 2005. An economic assessment of wildlife farming and conservation. Conservation Biology 19(4): 1222–1233. |
| 9. | Burgess, E., S. Stoner, and K. Foley. 2014. Brought to bear: an analysis of seizures across Asia (2000-2011). TRAFFIC, Petaling Jaya, Selangor, Malaysia. |
| 10. | Caussade, S., J. de Dios Ortúzar, L.I. Rizzi et al. 2005. Assessing the influence of design dimensions on stated choice experiment estimates. Transportation research part B: Methodological 39(7): 621–640. |
| 11. | Cerri, J., E.O. Davis, D. Veríssimo et al. 2021. Specialized questioning techniques and their use in conservation: a review of available tools, with a focus on methodological advances. Biological Conservation 257: 109089. |
| 12. | Challender, D.W., G.W. Ades, J.S. Chin et al. 2019. Evaluating the feasibility of pangolin farming and its potential conservation impact. Global Ecology and Conservation 20: e00714. |
| 13. | ChoiceMetrics. 2012. Ngene 1.0.1 User Manual & Reference Guide, Australia. |
| 14. | Crudge, B., N.M. Wilkinson, V.T. Do, T.D. Cao, T.T. Cao, A. Weegenaar, and M. Hunt. 2016. The status and distribution of bears in Vietnam. Free the Bears, Vietnam. |
| 15. | Crudge, B., T. Nguyen, and T.T. Cao. 2018. The challenges and conservation implications of bear bile farming in Viet Nam. Oryx 54(2): 252–259. |
| 16. | Crudge, B., C. Lees, M. Hunt et al. (eds.). 2019 . Sun bears: global status review & conservation action plan, 2019-2028. IUCN SSC Bear Specialist Group/IUCN SSC Conservation Planning Specialist Group/Free the Bears/TRAFFIC. |
| 17. | Davis, E.O., D. O'Connor, B. Crudge et al. 2016. Understanding public perceptions and motivations around bear part use: A study in northern Laos of attitudes of Chinese tourists and Lao PDR nationals. Biological Conservation 203(2016): 282–289. |
| 18. | Davis, E.O., J.A. Glikman, B. Crudge et al. 2019a. Consumer demand and traditional medicine prescription of bear products in Vietnam. Biological Conservation 235: 119–127. |
| 19. | Davis, E.O., B. Crudge, T. Lim et al. 2019b. Understanding the prevalence of bear part consumption in Cambodia: A comparison of specialised questioning techniques. PLoS One, 14(2): e0211544. |
| 20. | Davis, E.O., D. Veríssimo, B. Crudge et al. 2020a. Insights for reducing the consumption of wildlife: the use of bear bile and gallbladder in Cambodia. People and Nature 2(4): 950–963. |
| 21. | Davis, E.O., M. Gibson, T. Lim, and J.A. Glikman. 2020b. Bear bile use at the intersection of maternal health in Cambodia. Journal of ethnobiology and ethnomedicine 16: 1–9. |
| 22. | Davis, E.O., B. Crudge, and J.A. Glikman. 2020c. The nominative technique: a simple tool for assessing illegal wildlife consumption. Oryx, pp.1-4. |
| 23. | Davis, E.O. 2020. Understanding use of bear products in Southeast Asia: human-oriented perspectives from Cambodia and Laos. Ph.D. thesis. University of Bristol, England, U.K. |
| 24. | Davis, E.O. and J.A. Glikman. 2020. An assessment of wildlife use by Northern Laos nationals. Animals 10(4): 685. |
| 25. | Doughty, H., E.J. Milner-Gulland, J.S.H. Lee, K. Oliver, L.R. Carrasco, and D. Veríssimo. 2021. Evaluating a large-scale online behaviour change intervention aimed at wildlife product consumers in Singapore. PloS one 16(3): e0248144. |
| 26. | Drury, R.C. 2009. Identifying and understanding consumers of wild animal products in Hanoi, Vietnam: implications for conservation management. Ph.D. thesis. University College London, London, UK. |
| 27. | Drury, R. 2011. Hungry for success: urban consumer demand for wild animal products in Vietnam. Conservation and Society 9(3): 247–257. |
| 28. | Durant, L.E., M.P. Carey, and K.E. Schroder. 2002. Effects of anonymity, gender, and erotophilia on the quality of data obtained from self-reports of socially sensitive behaviors. Journal of Behavioral Medicine 25(5): 439–467. |
| 29. | Dushoff, J., M.P. Kain, and B.M. Bolker. 2019. I can see clearly now: reinterpreting statistical significance. Methods in Ecology and Evolution 10(6): 756–759. |
| 30. | Dutton, A.J., C. Hepburn, and D.W. Macdonald. 2011. A stated preference investigation into the Chinese demand for farmed vs. wild bear bile. PloS one 6(7): e21243. |
| 31. | |
| 32. | Feng, Y., K. Siu, N. Wang et al. 2009. Bear bile: dilemma of traditional medicinal use and animal protection. Journal of Ethnobiology and Ethnomedicine 5(1): 2 |
| 33. | Fisher, T.D. 2013. Gender roles and pressure to be truthful: The bogus pipeline modifies gender differences in sexual but not non-sexual behavior. Sex Roles 68(7): 401–414. |
| 34. | Foley, K.E., C. Stengel, and C. Shepherd. 2011. Pills, Powders, Vials and Flakes: the bear bile trade in Asia. TRAFFIC Southeast Asia, Petaling Jaya, Selangor, Malaysia. |
| 35. | Garshelis, D., and L. Scotson. 2012. World Conservation Congress votes to curtail bear farming. International Bear News 21(4). |
| 36. | |
| 37. | Haikui, H. and L. Zhi. 2007. Bear farming and bear conservation in China. In: Proceedings of the 4th international symposium on the trade in bear parts. Organised and published by TRAFFIC East Asia–Japan. October 4, 2006. Pp. 37–49. |
| 38. | Hinsley, A., D. Verissimo, and D.L. Roberts. 2015. Heterogeneity in consumer preferences for orchids in international trade and the potential for the use of market research methods to study demand for wildlife. Biological Conservation 190: 80–86. |
| 39. | Hinsley, A., A. Keane, F.A. St. John et al. 2019. Asking sensitive questions using the unmatched count technique: Applications and guidelines for conservation. Methods in Ecology and Evolution 10(3): 308–319. |
| 40. | Hinsley, A., S. Hu, H. Chen, D. Garshelis, M. Hoffmann, T.M. Lee, B. Moyle, Y. Qiu, X. Ruan, A.K.Y. Wan, J. Zhou, and E.J. Milner-Gulland. 2021. Combining data from consumers and traditional medicine practitioners to provide a more complete picture of Chinese bear bile markets. People and Nature. https://doi.org/10.1002/pan3.10249. Accessed on September 5, 2021. |
| 41. | Hoyos, D. 2010. The state of the art of environmental valuation with discrete choice experiments. Ecological Economics 69(8): 1595–1603. |
| 42. | Iannone, R., J. Cheng, and B. Schloerke. 2020. gt: Easily Create Presentation-Ready Display Tables. R package version 0.2.2. https://CRAN.R-project.org/package=gt. Accessed on October 20, 2020. |
| 43. | Klein, V., R. Imhoff, K.M. Reininger, and P. Briken. 2019. Perceptions of sexual script deviation in women and men. Archives of Sexual Behavior 48(2): 631–644. |
| 44. | |
| 45. | Lancsar, E. and J. Louviere. 2008. Conducting discrete choice experiments to inform healthcare decision making. Pharmacoeconomics 26(8): 661–677. |
| 46. | Lincoln, M. 2016. Alcohol and drinking cultures in Vietnam: a review. Drug and alcohol dependence 159: 1–8. |
| 47. | Livingstone, E., C. Shepherd. 2016. Bear farms in Laos expand illegally and fail to conserve wild bears. Oryx 50(1): 1–9 |
| 48. | Livingstone, E., L. Gomez, and J. Bouhuys. 2018. A review of bear farming and bear trade in Lao People's Democratic Republic. Global Ecology and Conservation: e00380. |
| 49. | Moran, L.M., W.J. Kowalczyk, K.A. Phillips, M. Vahabzadeh, J.L. Lin, M. Mezghanni, D.H. Epstein, and K.L. Preston. 2018. Sex differences in daily life stress and craving in opioid-dependent patients. The American journal of drug and alcohol abuse 44(5): 512–523. |
| 50. | Naono, A. 2014. “Rural” health in modern Southeast Asia. In: Histories of Health in Southeast Asia: Perspectives on the Long Twentieth Century (eds. Harper T. and S. Amrith) Pp. 99–117. Indiana University Press. Retrieved from http://www.jstor.org/stable/j.ctt16gh8fn.10. Accessed on March 20, 2021. |
| 51. | Nuno, A., J.M. Blumenthal, T.J. Austin et al. 2018. Understanding implications of consumer behaviour for wildlife farming and sustainable wildlife trade. Conservation Biology 32(2): 390–400. |
| 52. | R Core Team. 2020. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/ |
| 53. | Rigby, D. and M.P. Burton. 2003. Capturing preference heterogeneity in stated choice models: a random parameter logit model of the demand for GM food (No. 414-2016-26059). |
| 54. | |
| 55. | 't Sas-Rolfes, M., D.W. Challender, A. Hinsley et al. 2019. Illegal wildlife trade: scale, processes, and governance. Annual Review of Environment and Resources 44: 201–228. |
| 56. | |
| 57. | Turvey, S.T., S. Chen, B. Tapley et al. 2021. From dirty to delicacy? Changing exploitation in China threatens the world's largest amphibians. People and Nature 3(2): 446–456. |
| 58. | Veríssimo, D., T. Pongiluppi, M.C.M. Santos, P.F. Develey, I. Fraser, R.J. Smith, and D.C. MacMilan. 2014a. Using a systematic approach to select flagship species for bird conservation. Conservation Biology 28(1): 269–277. |
| 59. | Veríssimo, D. and A.K.Y. Wan. 2019. Characterizing efforts to reduce consumer demand for wildlife products. Conservation Biology 33(3): 623–633. |
| 60. | Veríssimo, D., M. 't Sas-Rolfes, and J.A. Glikman. 2020. Influencing consumer demand is vital for tackling the illegal wildlife trade. People and Nature 2(4): 872–876. |
| 61. | Vié, J.C., C. Hilton-Taylor, and S.N. Stuart (eds.). 2009. Wildlife in a changing world: an analysis of the 2008 IUCN Red List of threatened species. Gland, Switzerland: IUCN. |
| 62. | |
| 63. | Willcox, D., N.D.T. Minh, and L. Gomez. 2016. An assessment of trade in bear bile and gall bladder in Viet Nam. TRAFFIC, Petaling Jaya, Selangor. |
[Figure 1], [Figure 2]
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