Materials and Methods
This section presents the study area, methods of data collection and analysis.
Study area
The north Bengal landscape comprises fragmented forests, tea gardens, tributaries and distributaries, agricultural fields, and defence establishments intersected by railways and highways (Figure 1). While there has been a constant decrease in the wildlife habitat over the last few decades, the four districts of north Bengal, namely – Darjeeling, Kalimpong, Jalpaiguri, and Alipurduar, together host more than five hundred elephants (MoEF & CC Report, 2017). The land-use and landcover analysis highlights a forty four percent increase in human settlements and a seven percent decrease in the sand bed area in the last decade (Naha et al. 2019). Parallelly, Roy and Sukumar (2015) identified 59 elephant corridors, while eighty percent of these corridors experience a high degree of encroachment. With shrinking ecological corridors but considerate peoples’ tolerance (Roy et al. 2022), the elephant population increases and is ’pushed’ through tea gardens, cited as ’natural corridors’ in modern human-elephant conflict literature. Exponential increase from 10,000 acres in 1866 to 50,000 acres in 1905, the tea industry has emerged as a static livelihood option to many and welcomed many migrants (Xaxa, 2019). The numbers grew further over the next century and currently covers approximately 1350 km2 of land (Kshettry et al. 2020).
Data collection
We triangulated the findings through opportunistic observation, digital photography and fieldnotes, and postmortem examination reports. These are explained below:
Opportunistic observation
The jurisdiction of wildlife divisions in north Bengal spreads across forest villages, revenue lands, tea gardens, and any other area where wildlife is present. The four discussed case reports originated through opportunistic observation. This method corresponds to spontaneous observation and recording of the behaviour of any natural event by the researcher or any concerned individual (Altmann, 1974; Carter et al., 2020; Pokharel et al., 2021). The researcher then captures the event through photography, field notes, videography, or audio recording, followed by long-term observation.
Digital photography and fieldnotes
The researchers took photographs of these burial incidents, forest department officials and the tea garden management, which were later analyzed (Silva et al. 2017; Goldenberg and Wittemyer 2019; Carter et al. 2020). The researchers and tea garden management collected evidence of elephant visitation around the burial site. All the burial sites were far from human settlements, and identifying the particular elephant herd at night was challenging for the locals. However, the researchers and tea garden management regularly monitored the specific pathways while preparing field notes to look for indirect evidence such as dung boli and footsteps.
Postmortem examination reports
Four veterinary officers conducted the postmortem report in the presence of the forest officers of respective wildlife divisions. The postmortem report of the deceased calves reveals the reason for deaths, underlying illness, health conditions, and various parameters (see Table 1). While other scholarships suspect the cause of calves’ death through indirect evidence (Goldenberg and Wittemyer 2019; Sharma et al. 2019), this study gives detailed proof of the cause of death. Also, note that the postmortem examination report reflects the estimated time of death of the calf and deduces the ’in-transit’ time and the time under the ground.