Our new publication: Camera‐trapping reveals new insights in the ecology of three sympatric muntjacs in Nakai-Nam Then National Park

Study area map of Nakai- Nam Theun national Park, Laos. Camera trapping was conducted in three different management zones between February 2018 and May 2019

We conducted a landscape-scale systematic camera-trapping surveys (overall >20,000 camera-trap nights) in Nakai-Nam Theun National Park in 2018-2019. We analyzed camera-trap muntjac photograph records to evaluate the three species’ responses to environmental and anthropogenic variables, and to predict their distributions across the protected area.

Our research and analysis main observations and conclusions are:

• The three species of muntjac show varying responses to the variables, indicating complex drivers of occurrence
• Annamite dark muntjac was predominantly found at higher elevations, consistent with previous qualitative assessments that the species complex is more common in highland areas across its range
• Northern red muntjac occupancy peaked at approximately 1250 m asl., but declined at elevations above this, consistent with previous assessments that in Laos the northern red muntjac may be uncommon above 1500 m asl
• Large-antlered muntjac was predicted to range at higher elevations: contradicting previous speculations that the species predominantly occurs below 1000 m asl due to ecological habitat associations
• All three muntjac had higher occupancies in more inaccessible areas, as their populations are likely depressed by hunting pressure in less remote areas. From a conservation perspective, such a finding is more worrisome for large-antlered muntjac, given its Critically Endangered conservation status (the species is endemic to the Annamite Mountains: a restricted world range)
• The mean Percentage Area of Occupancy across the national park was higher for large-antlered muntjac, followed by Annamite dark muntjac and then northern red muntjac
• Large-antlered muntjac and northern red muntjac were distributed more widely across the national park, while Annamite dark muntjac was restricted to high elevation areas
• Given the high occupancies that we found for the Critically Endangered large-antlered muntjac, we argue that Nakai-Nam Theun National Park may be vital for the long-term survival of the species. Securing large-antlered muntjac, as well as other Annamite endemic species that are still present in Nakai-Nam Theun NP, is critical for the conservation of these species in the Annamite mountains.
• Assessing population changes over time is an integral part of adaptive management: Percentage of Area Occupied (PAO), occupancy estimates, and predictive maps all provide information that can be used to inform conservation decisions in Nakai- Nam Theun NP.
• Our occupancy estimates provide a robust conservation baseline for each muntjac and management zone, which can, in turn, be used to assess population trends and, ultimately, the effectiveness of conservation interventions.