Using interviews and biological sign surveys to infer seasonal use of forested and agricultural portions of a human-dominated landscape by Asian elephants in Nepal

Abstract

Understanding how wide-ranging animals use landscapes in which human use is highly heterogeneous is important for determining patterns of human–wildlife conflict and designing mitigation strategies. Here, we show how biological sign surveys in forested components of a human-dominated landscape can be combined with human interviews in agricultural portions of a landscape to provide a full picture of seasonal use of different landscape components by wide-ranging animals and resulting human–wildlife conflict. We selected Asian elephants (Elephas maximus) in Nepal to illustrate this approach. Asian elephants are threatened throughout their geographic range, and there are large gaps in our understanding of their landscape-scale habitat use. We identified all potential elephant habitat in Nepal and divided the potential habitat into sampling units based on a 10 km by 10 km grid. Forested areas within grids were surveyed for signs of elephant use, and local villagers were interviewed regarding elephant use of agricultural areas and instances of conflict. Data were analyzed using single-season and multi-season (dynamic) occupancy models. A single-season occupancy model applied to data from 139 partially or wholly forested grid cells estimated that 0.57 of grid cells were used by elephants. Dynamic occupancy models fit to data from interviews across 158 grid cells estimated that monthly use of non-forested, human-dominated areas over the preceding year varied between 0.43 and 0.82 with a minimum in February and maximum in October. Seasonal patterns of crop raiding by elephants coincided with monthly elephant use of human-dominated areas, and serious instances of human–wildlife conflict were common. Efforts to mitigate human–elephant conflict in Nepal are likely to be most effective if they are concentrated during August through December when elephant use of human-dominated landscapes and human–elephant conflict are most common.

key words:

• Asian elephant
• human–wildlife conflict
• Nepal
• occupancy
• seasonal use

ACKNOWLEDGEMENTS

We would like to thank Government of Nepal, Department of National Parks and Wildlife Conservation and Department of Forests, for providing the necessary permits and support for the survey. This study would not have been possible without the financial support of the USAID-Hariyo Ban Program. We are thankful to all four consortium partners of Hariyo Ban Program (WWF, Care, FECOFUN and NTNC). We would like to thank the entire survey team, especially the wildlife technicians of NTNC’s different field stations, for their tireless effort to complete the field survey. We thank all the respondents of the interview. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the US Government.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the United States Agency for International Development [Hariyo Ban Program].