Toward Human-Carnivore Coexistence: Understanding Tolerance for Tigers in Bangladesh

Fostering local community tolerance for endangered carnivores, such as tigers (Panthera tigris), is a core component of many conservation strategies. Identification of antecedents of tolerance will facilitate the development of effective tolerance-building conservation action and secure local community support for, and involvement in, conservation initiatives. We use a stated preference approach for measuring tolerance, based on the ‘Wildlife Stakeholder Acceptance Capacity’ concept, to explore villagers’ tolerance levels for tigers in the Bangladesh Sundarbans, an area where, at the time of the research, human-tiger conflict was severe. We apply structural equation modeling to test an a priori defined theoretical model of tolerance and identify the experiential and psychological basis of tolerance in this community. Our results indicate that beliefs about tigers and about the perceived current tiger population trend are predictors of tolerance for tigers. Positive beliefs about tigers and a belief that the tiger population is not currently increasing are both associated with greater stated tolerance for the species. Contrary to commonly-held notions, negative experiences with tigers do not directly affect tolerance levels; instead, their effect is mediated by villagers’ beliefs about tigers and risk perceptions concerning human-tiger conflict incidents. These findings highlight a need to explore and understand the socio-psychological factors that encourage tolerance towards endangered species. Our research also demonstrates the applicability of this approach to tolerance research to a wide range of socio-economic and cultural contexts and reveals its capacity to enhance carnivore conservation efforts worldwide

Predation Risk Shapes Social Networks in Fission-Fusion Populations

Predation risk is often associated with group formation in prey, but recent advances in methods for analysing the social structure of animal societies make it possible to quantify the effects of risk on the complex dynamics of spatial and temporal organisation. In this paper we use social network analysis to investigate the impact of variation in predation risk on the social structure of guppy shoals and the frequency and duration of shoal splitting (fission) and merging (fusion) events. Our analyses revealed that variation in the level of predation risk was associated with divergent social dynamics, with fish in high-risk populations displaying a greater number of associations with overall greater strength and connectedness than those from low-risk sites. Temporal patterns of organisation also differed according to predation risk, with fission events more likely to occur over two short time periods (5 minutes and 20 minutes) in low-predation fish and over longer time scales (>1.5 hours) in high-predation fish. Our findings suggest that predation risk influences the fine-scale social structure of prey populations and that the temporal aspects of organisation play a key role in defining social systems

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Theoretical tolerance model.

<p>Black arrows represent the hypothesized direct relationships between experience, psychological variables and tolerance for tigers tested in the paper. Black dotted arrow represents the hypothesized indirect effect of experience on tolerance for tigers. Grey boxes (H1-6) identify each of the hypotheses described in the text and tested in our model. Grey dashed arrows represent how knowledge of the antecedents of tolerance can be applied to improve tiger conservation strategies.</p

Map of study area and study villages.

<p>The location of the six case study villages, including the two villages where stray tigers were killed in 2010 (TK villages), additional piloting villages (initial piloting was carried out in case study villages), and the 10 questionnaire survey villages are shown. The eight ‘<i>upazilas</i>’ (sub-districts) which border the Sundarbans are delineated as are the three wildlife sanctuaries within the Sundarbans which comprise a UNESCO World Heritage Site. The four Sundarbans ranges (Forest Department administrative units) are shown; the West Forest Division comprises Satkhira and Khulna ranges and the East Forest Division comprises Chandpai and Sarankhola ranges.</p

The psychological basis for tolerance of tigers in the Bangladesh Sundarbans.

<p>Continuous arrows represent significant direct effects. Dashed arrows represent significant indirect effects. Grey arrow represents the anomalous effect of livestock depredation upon tolerance. Non-significant effect pathways are not shown. Tiger Population: belief about the current tiger population trend. Village-based tiger incidents include tigers entering villages, tigers attacking livestock in villages or tigers attacking people in villages. Standardized regression weights are shown for direct and indirect pathways; where different to the direct effect regression weight, total effects standardized regression weights are shown in brackets. All values are significant at either the 0.05 or 0.01 levels (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0145913#pone.0145913.t003" target="_blank">Table 3</a>).</p

Human-Tiger conflict in context: risks to lives and livelihoods in the Bangladesh Sundarbans.

People’s perceptions of the risk posed by wild animals to human lives and/or livelihoods can influence the rate at which people intentionally kill these species. Consequently, human–wildlife conflict (HWC) management strategies may benefit from the inclusion of actions which reduce risk perceptions. This study uses Participatory Risk Mapping (PRM) and semi-structured interviews to explore local perceptions and the wider socio-economic context of human–tiger conflict (HTC)in the Bangladesh Sundarbans area. Of the 24 locally-relevant problems identified by the PRM process, tigers were the only problem to be cited by >50 % of respondents. The ‘tiger problem’ was also perceived by villagers to be of relatively high severity. Negative perceptions of tigers in the Sundarbans communities are exacerbated by other locally-experienced poverty-related problems, as well cyclones, floods and soil erosion. Interactions between the problems experienced by villagers, including HTC, result in a complex ‘risk web’ which detrimentally affects lives and livelihoods and ultimately perpetuates poverty levels in the Sundarbans communities. This research demonstrates that PRM and in-depth, qualitative research can enhance understanding of the perceived magnitude and wider socio-economic context of risks from wildlife and aid the identification of risk perception management actions which may help to reduce the number of animals killed by people. Panthera tigris . Human–wildlife conflict . Risk perception . Poverty . Sundarban

Local Usage of Tiger Parts and Its Role in Tiger Killing in the Bangladesh Sundarbans

This article explored the local medicinal and traditional values of tiger parts and associated beliefs, and its link to the commercial trade in the Bangladesh Sundarbans. Using semi-structured qualitative interviews with 139 respondents, we found that the local use of, and belief in, the medicinal values of tiger parts is widespread and that virtually all parts of the tiger are used. Some of the local uses of tiger parts were unique in both the way and the purpose of use. For example, the soil of tiger pugmark was consumed by the women as a means of contraception. We established that local usage may be a significant threat to the tiger population of south Asia as it motivates stray tiger killing for collecting tiger parts for both local use and commercial demand, and provides the opportunities for poachers and the commercial trade to flourish