Hydropower activities, road construction, and housing developments threaten the endangered primate, Golden Langur (Trachypithecus geei), a research study has found.
The impact of these activities on the species’ habitat was high based on the scope, severity, and irreversibility of impacts.
Wildlife biologist, Phuntsho Thinley (PhD) and his team of foresters published the findings in Springer last year. The rankings were based on Miradi threat ranking analysis which was used to analyse the threats posed by developmental activities like hydropower activities and population threats such as electrocution, roadkill, and retaliatory killing, among others.
Agricultural expansion, resource extraction, electrocution, and roadkill had a medium impact on the habitat of the species.
From June 2012 until June last year, a total of 107 incidents of population threats to golden langurs were recorded from which mortality or injury was 50, 30 electrocuted, 15 were killed on roads, 15 dog kills, six retaliatory killings, four road injuries, and two cases of pet keeping.
More than 1,000 households within 34 gewogs in six dzongkhags— Dagana, Sarpang, Trongsa, Tsirang, Wangdue, and Zhemgang, located inside the three protected areas of Jigme Singye Wangchuck National Park, Royal Manas National Park, and Phibsoo Wildlife Sanctuary were interviewed for the study.
Forestry staff trained for golden langur surveys listed 15 incidents of population threats. They listed habitat threats from resource extraction (collection of firewood, timber, non-timber forest products, stones, boulders, and sand), agricultural expansion (development of agricultural fields and irrigation canals), and illegal plantation of cash crops such as cardamom in forests, among others.
The study found that the threats from roadkills and electrocution required immediate intervention. Most roadkills occurred in Sarpang along the Gelephu-Sarpang road and in Zhemgang along the Dakphel-Zhemgang road and Dakphel-Tingtibi road. “The Gelephu-Sarpang road is particularly dangerous because of its flat terrain which encourages vehicles to speed faster than 100 km/h.”
Electrocutions of the species occurred around 440kV (kilovolt) of uninsulated exposed electric cables.
To immediately mitigate these threats, the study recommended installing speed limit signage and speed breakers with strict enforcement of speed limits, installing insulated electric cables and fencing around power transformers, and reducing and restraining dog population in the core habitat areas.
Golden langur is listed as endangered species in the IUCN Redlist of threatened species and listed in Appendix-I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora It has been recognised as one of the world’s 25 most endangered primates.
In Bhutan, it is fully protected in Schedule I of both the Forest and Nature Conservation Act and Forest and Nature Conservation Rules and Regulations of Bhutan.