Effects of a highway on the genetic diversity of Asiatic black bears

A highway separating two parts of the Dong Phayayen-Khao Yai Forest Complex in Thailand acts as a significant dispersal barrier for Asiatic black bears (Ursus thibetanus), with a current migration rate of just 1% between the populations. Despite similar genetic diversity levels, the study found notable differentiation (FST = 0.035) and no strong evidence of inbreeding, suggesting long-term effects of habitat fragmentation. The effective population size (Ne = 178 bears) is below recommended thresholds, raising conservation concerns. Simulations predict a strong negative impact on genetic diversity within the next decade if isolation persists. Noninvasive hair sampling and microsatellite analysis of 95 individuals revealed these patterns, highlighting the potential for assisted migration via habitat corridors to mitigate road impacts.

Vaeokhaw, S., Ngoprasert, D., Swatdipong, A., Gale, G. A., Klinsawat, W., & Vichitsoonthonkul, T. (2020). Effects of a highway on the genetic diversity of Asiatic black bears. Ursus, 2020(31e3), 1. https://doi.org/10.2192/ursus-d-18-00013.2