No Reliable Evidence Supports the Presence of Javan Tigers - Data Issues Related to the DNA Analysis of a Recent Hair Sample

A paper recently published in Oryx by Wirdateti et al. (2024) suggests that the extinct Javan tiger may still survive on the Island of Java, Indonesia, based on mtDNA analysis of a single hair collected from a claimed tiger encounter site. After carefully re-analyzing the data presented in Wirdateti et al. (2024), we conclude that there is little support for the authors’ statements. Importantly, the sequences of the putative tiger hair and museum Javan tiger specimens generated by the authors are not from tiger cytoplasmic mitochondrial DNA but more likely the nuclear copies of mitochondrial DNA. In addition, the high mismatches found between the two “Javan tiger” sequences generated by the authors is unusual for homologous sequences that are both from tigers and hence indicative of data unreliability. Yet, too few details regarding the quality control were provided in Wirdateti et al. (2024) to rule out the possibility of contamination introduced during the data production process. In conclusion, it is inappropriate to use these unreliable sequences presented in Wirdateti et al. (2024) to infer the existence of the Javan tiger.