Globally, tropical rain forests are among the most species-rich habitats and are therefore often prioritised in conservation efforts. A team of scientists from Viet Nam and Germany now show that the diversity of ground-dwelling mammals and birds in Nui Chua National Park (Viet Nam) is highest in semi-dry forest, the transitional habitat where dry and wet evergreen broadleaf forest habitats meet. These results highlight the conservation importance of habitat transition zones, the scientists write in a paper published in the journal “Biotropica”.

Nui Chua National Park, located in southern Viet Nam, is the only National Park within the coastal dry forest landscape of the country. The protected area is unique for its habitat diversity, with dry forest at low elevations, semi-dry forest in a transitional area and wet evergreen forest at high elevations. The National Park gained attention in 2018 when the silver-backed chevrotain (Tragulus versicolor) was rediscovered by scientists there.

To acquire baseline data on species occurrence and distribution in Nui Chua NP, a team of scientists conducted five camera trap surveys between 2018 and 2022. “While searching for the silver-backed chevrotain in the park, I was surprised by the high number of records of other species in the forest area where we rediscovered this endemic species”, says An Nguyen, doctoral student in the Department of Ecological Dynamics at the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW). “This inspired us to look beyond the species level and investigate the ground-dwelling mammal and bird community in Nui Chua NP.” The team set up a total of 145 camera trap stations across the park to survey ground-dwelling mammals and birds. “The highest diversity was found in the semi-dry transition areas between the coastal dry forest and the high elevation rainforest.”

“Detailed insights into the occurrence and distribution of wildlife can help conservation planning and the prioritisation of limited conservation resources”, says Tran Van Tiep, Director of Nui Chua National Park. “Our results suggest we should pay special attention to semi-dry forest areas for conservation efforts in Nui Chua NP, particularly since this habitat has the highest biodiversity and highest occupancy of the highly threatened silver-backed chevrotain, the flagship species of our park. As these important transition habitats occur within the buffer zone but outside the National Park, we should consider including them within the park’s core zone.” The fact that the highly threatened silver-backed chevrotain likely has its largest population in the semi-dry forests of Nui Chua provides an additional incentive for protecting this habitat. Moving beyond Nui Chua NP, the scientists recommend that conservationists identify other semi-dry forest areas in the wider coastal dry forest landscape and protect these forests.

“The findings from this survey are in line with the exceptionally high botanical diversity that we have documented in the semi-dry coastal forest habitat”, says Truong, botanist and Director of the Southern Institute of Ecology. “This provides further evidence of the conservation importance of this transitional habitat, and the need to protect it along the coastal provinces of southern Viet Nam.”