Nyhus, P. | bioRxiv Science

bioRxiv2024

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.

zoology↗

bioRxiv2020

The Past, Present and Future of Elephant Landscapes in Asia

Habitat loss drives species declines worldwide, but is seldom quantified over centennial timescales. We constructed ecological niche models for Asian elephants based on land-use change between 850-2015, and predictions under six different climate/socioeconomic scenarios from 2015-2099. We find that over 64% of suitable natural habitat across diverse ecosystems was lost over the past three centuries. Average patch size dropped 83% from approximately 99,000 km2 to 16,000 km2 and the area occupied by the largest patch decreased 83% from ~ 4 million km2 (45% of area) to 54,000 km2 (~7.5% of area). Over half of current elephant range appears unsuitable. Habitat availability is predicted to decline further this century across all scenarios. The most severe losses occur under RCP3.4-SSP4, representing mid-range emissions but high regional inequities. We conclude that climate change mitigation measures must include policies to ensure inter-regional socioeconomic equity to safeguard landscapes for elephants, humans, and other species.

ecology↗