What else should we know to conserve Asian elephants?

Monitoring mortality patterns of elephants in Sri Lanka

from LaDue et al., 2021:
Many wildlife species suffer from human–wildlife conflict, especially crop-raiding. Long-term analyses of mortality patterns are needed to assess the efficacy of management strategies that address this issue. In a recent study, we reported mortality patterns from necropsies of 498 Asian elephants from 2009–2018 in an area of northwestern Sri Lanka. Deaths were lowest in July and highest in October, a period of peak crop availability. Most (about 70%) deaths were human-related, and males were killed in these incidents more frequently than females. As gunshot deaths decreased, other forms of human-related deaths increased. Additionally, causes of death differed between districts, with more intentional human-related mortality observed in the district with the highest percent of protected land.

These results have broader implications for addressing human−wildlife conflict (HWC) and more specifically, the pressing challenge of crop-raiding. Several times in the recent past, Sri Lanka has implemented strategies to mitigate and reduce HWC, similar to various regions globally with elephants and other species. Despite these attempts, the dynamic dimensions of HWC challenge short-term mitigation strategies. For example, in this region it was clear that elephant deaths from gunfire decreased dramatically with increased gun control among civilians. Other forms of intentional killing increased over the same period, demonstrating the continued persistence of the conflict. Only long-term studies of wildlife mortality such as this one can shed light on the efficacy of management strategies that address HWC. The changing nature of HWC and crop-raiding at temporal and spatial scales also necessitates adaptive response strategies. For example, in this study there were differences in mortality patterns between adjacent districts based on the proportion of protected land available (and concomitantly, human density), requiring an approach that considers regional and local differences in habitat quality and food and crop availability for wildlife. Despite the efforts of various groups (e.g., DWC and related agencies in Sri Lanka) to foster coexistence between wildlife and people, it is clear that human agricultural communities will turn to lethal deterrents when their physical safety and financial security are at risk. The burden of HWC may disproportionately affect a subset of an area’s human population, but such conflict has wide-ranging consequences for food security and economic prosperity. Long-term studies have the potential to assist with mitigation strategies that adapt to changing pressures and factors leading to HWC.

Permanent scars of human−elephant conflict

from LaDue et al., 2021:

Human–elephant conflict (HEC) is a major threat to Asian elephants as humans and elephants are forced to share common resources. In Sri Lanka, human-dominated landscapes adjacent to protected areas promote high rates of HEC, especially in the form of crop-foraging by elephants. Crop-foraging can be dangerous to both elephants and humans involved in the conflict. Gunfire is a common way for human communities to deter crop-foraging elephants. While observing elephants in a protected area in Sri Lanka, Wasgamuwa National Park, we noted the common occurrence of circular scars on elephants, similar in appearance to scar tissue resulting from surface abrasions or lesions. The scars were located in unique patterns over the bodies of each elephant, serving as reliable distinguishing features among elephants. We presumed that most of these scars were incurred through gunfire, a common HEC deterrent in the region, as bullets and/or pellets are found inside many of elephants with these scars on necropsy. Other causes for these scars were cautiously excluded because of unique properties of the elephants in Sri Lanka. Therefore, it stands to reason that elephants that engage in HEC more often should have more scars. We hypothesised that the scars in this population of Asian elephants may serve as permanent indicators of their experience with HEC, potentially aiding in the development of tailored HEC mitigation strategies towards the specific elephants that are most active in the conflict. By testing predictions of inter-individual variation in HEC that would be expected on the basis of sex and age differences, we aimed to validate these scars as useful tools to monitor patterns of HEC.

We identified 38 adult female and 64 adult male elephants and recorded the age class and body condition of each with established standards. Using photographs, we counted the number, position, and relative size of all scars on each animal. Of the 38 adult female elephants in the study, 19 had visible scars (50.00%), and 53 of 64 males (82.81%) had scars. The maximum number of scars observed on a single elephant was 100 (on a male). Age, sex, and BCS, along with the interactions between age and sex, and age and body condition, significantly affected the number of scars visible on an elephant. Male elephants had significantly more scars than did females. Scars were apparent among adult males in the youngest ages categories, from 10 to 20 years, and males from older age groups had significantly more scars than did younger males. Significantly more scars appeared on female elephants between the ages of 20 and 30 years, but the number of scars did not increase with older age in these females. Males with higher, fatter body conditions had more scars than did males of lower, thinner body condition. For female elephants, very few scars were located in the head region (averaging 0.44% of all scars on each elephant) compared with the mid-section and rear. Males averaged proportionately more scars on their head (averaging 6.65% of scars) than females did, but for males, there were still proportionally more scars on the mid-section, and even more on the rear. However, as male elephants aged, there were proportionally more scars located towards the anterior of the body than on the posterior part, and by age 40 years, there were proportionally more scars on the mid-section than on the rear.

The present study has contributed to human−elephant coexistence by identifying elephants that are most apt to engage in HEC, including how these tendencies change over time. Considering the elephants’ perspective in HEC will involve taking into account individual variation in response patterns to ever-changing environments. Our results, combined with those of other studies, indicated that elephants differ in their propensity to be involved in various forms of HEC. Studies such as these emphasise how HEC mitigation strategies should adapt on the basis of the identities of elephants in a particular area. HEC is constantly evolving, necessitating dynamic conflict resolution plans that integrate both human and animal perspectives in real-time. Our study showed the changing responses of elephants to human landscapes, with contributing factors such as sex and age, by using a method that is efficient and requires few resources. By targeting and characterising the elephants, communities and landscapes involved in specific areas of concern, more effective management plans can be developed for an increasingly modernised world.