Details

Autor(en) / Beteiligte

• Budd, Kris
• Suddychan, Daophone
• Tyson, Martin
• Coudrat, Camille N. Z.
• McWilliam, Alex
• Hallam, Christopher D.
• Johnson, Arlyne
• Eggert, Lori S.

Titel

Effects of a hydropower project on a high‐value Asian elephant population

Ist Teil von

• Ecology and evolution, 2023-07, Vol.13 (7), p.e10353-n/a

Ort / Verlag

England: John Wiley & Sons, Inc

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Habitat loss and fragmentation are leading contributors to the endangered status of species. In 2006, the Nakai Plateau contained the largest known Asian elephant (Elephas maximus) population in the Lao People's Democratic Republic (Lao PDR), and the population was among those with the highest genetic diversity reported for Asian elephants. In 2008, completion of the Nam Theun 2 hydroelectric dam inundated much of the Plateau, resulting in the loss of 40% of elephant habitat. We studied elephant presence, movements, and the incidence of human–elephant conflict (HEC) on the Nakai Plateau and surrounding areas from 2004 to 2020, before and for 12 years after dam completion. To examine contemporary population dynamics in the Nakai elephants, we used genetic sampling to compare minimum population numbers, demography, and levels of genetic diversity from the wet and dry seasons in 2018/2019, 10 years after dam completion, with those reported in a pre‐dam‐completion genetic survey. After dam completion, we found a major increase in HEC locally and the creation of new, serious, and persistent HEC problems as far as 100 km away. While we were unable to compare estimated population sizes before and after dam completion, our data revealed a decrease in genetic diversity, a male‐biased sex ratio, and evidence of dispersal from the Plateau by breeding‐age females. Our results raise concerns about the long‐term viability of this important population as well as that of other species in this region. Given that hydropower projects are of economic importance throughout Laos and elsewhere in southeast Asia, this study has important implications for understanding and mitigating their impact. We studied elephant presence, movements, and the incidence of human‐elephant conflict (HEC) on the Nakai Plateau, Lao PDR, and surrounding areas before and for 12 years after the completion of the Nam Theun 2 hydroelectric dam. We also used genetic data to compare the population 10 years after dam completion to data from a pre‐dam completion survey. Our results demonstrate a major increase in HEC both locally and as far as 100 km away from the Plateau during the study period, a decrease in genetic diversity, a shift in the sex ratio, and an increase in the proportion of subadult males in the population. Our results provide insights into not only the direct local impacts of habitat loss and fragmentation on elephant populations, but also the longer term landscape‐level effects.