Geographical distribution of Hylobates lar subspecies throughout South-East Asia (adapted from Thinh et al. 2010; Brockelman and Geissmann, 2020). Black squares represent individuals of known exact locations while blue squares indicated the approximate locations of the confiscated and surrendered individuals used in this study. Numbers on the map corresponds to the location in Table 1. The approximate location of the Isthmus of Kra, the Surat Thani-Krabi depression, and the Kangar-Pattani line are indicated by the grey, red, and green lines, respectively, marking the possible break among the Indochinese (carpenteri, entelloides, and yunnannesis) from the lar subspecies.