Unveiling the Impact of Human Influence on Species Distributions in Vietnam: A Case Study Using Babblers (Aves: Timaliidae)

Abstract

As developing countries give priority to economic growth, the effects of development threaten natural habitats and species distributions. Over the course of two decades, Vietnam has rapidly developed, especially in the expansion of agricultural production. However, no study has quantitatively measured the effects of recent human impact on the effects of past species distributions in Vietnam. We use locality data collected from multiple natural history collections, including several in Vietnam, to infer past species distributions. We assess habitat availability of five common babbler species (Aves: Timaliidae) using distribution models with data prior to rapid development that followed political reform. Overlaying the Global Human Influence Index with predicted distributions highlights the human impact on these distributions. Three important patterns emerge: (1) human impact influences common Timaliidae distributions similarly, (2) widespread species distributions show higher fragmentation due to human influence compared to narrowly distributed species in Vietnam, and (3) less than 20% of distributions overlap with nationally declared protected areas. We emphasize that conservation efforts should not only prioritize individual species, but also focus efforts on a regional scale, and that the use of museum data can be highly informative in conservation analyses. There are current obstacles to enforcing conservation of Vietnam's already fragmented habitats, but our results suggest there is still time to reevaluate conservation approaches.

A new locally collected environmental quality indicator for medium and large mammals

“…It is a global dataset of 1-kilometer grid cells, composed of nine global data layers covering human population pressure (population density), human land use and infrastructure (built-up areas, nighttime lights, land use/land cover), and human access (coastlines, roads, railroads, navigable rivers). It has been used to indicate conservation priority areas (Oliveira et al 2022), to evaluate human impact on avian distribution (Yohe et al 2014), as proxy of propagule pressure of alien species (Gallardo et al 2015), hunting pressure and is related to ungulates density (Martínez□Gutiérrez et al 2018). However, it may not be adequate for some situations once it may fail to incorporate local nuances.…”