Determining threatened species distributions in the face of limited data: Spatial conservation prioritization for the Chinese giant salamander (Andrias davidianus)

Abstract

The purpose of this study was to determine whether limited occurrence data for highly threatened species can provide useful spatial information to inform conservation. The study was conducted across central and southern China. We developed a habitat suitability model for the Critically Endangered Chinese giant salamander (Andrias davidianus) based on one biotic and three abiotic parameters from single‐site locality records, which represent the only relevant environmental data available for this species. We then validated model quality by testing whether increased percentage of predicted suitable habitat at the county level correlated with independent data on giant salamander presence. We randomly selected 48 counties containing historical records which were distinct from, and independent of, the single‐site records used to develop the model, and 47 additional counties containing >50% predicted suitable habitat. We interviewed 2,812 respondents near potential giant salamander habitat across these counties and tested for differences in respondent giant salamander reports between counties selected using each method. Our model predicts that suitable giant salamander habitat is found widely across central and southern China, with counties containing ≥50% predicted suitable habitat distributed in 13 provinces. Counties with historical records contain significantly more predicted suitable habitat than counties without historical records. There are no statistical differences in any patterns of respondent giant salamander reports in surveyed counties selected from our model compared with the areas of known historical giant salamander distribution. A Chinese giant salamander habitat suitability model with strong predictive power can be derived from the restricted range of environmental variables associated with limited available presence‐only occurrence records, constituting a cost‐effective strategy to guide spatial allocation of conservation planning. Few reported sightings were recent, however, with most being over 20 years old, so that identification of areas of suitable habitat does not necessarily indicate continued survival of the species at these locations.

Historical museum collections clarify the evolutionary history of cryptic species radiation in the world's largest amphibians

“…These separate drainages represent distinct biogeographic regions with independent geological histories and exhibit substantial endemism in freshwater taxa (Fei et al, ; Shih & Ng, ; Xing, Zhang, Fan, & Zhao, ; Zieritz et al, ). Giant salamanders are fully aquatic and occur in fast‐flowing tributaries within mountainous landscapes (Chen et al, ) across a series of different montane ecoregions that also represent areas of extensive local endemism (López‐Pujol, Zhang, Sun, Ying, & Ge, , ; Tang, Wang, Zheng, & Fang, ), and that can act as watersheds for multiple river drainages (e.g., Nanling mountains separate the Yangtze and Pearl drainages; Huangshan separates the Yangtze and Fujian‐Zhejiang hills drainages). Previous molecular phylogenetic analyses of giant salamander samples collected from across China (Murphy, Fu, Upton, Lema, & Zhao, ; Tao, Wang, Zheng, & Fang, ; Wang, Zhang, Xie, Wei, & Jiang, ; Yan, Lü, et al, ), which were investigated using isozymes, mitochondrial genes, microsatellites, or single nucleotide polymorphisms (SNPs), have identified genetically distinct local populations (e.g., a genetically distinct population from Huangshan; Murphy et al, ; Yan, Lü, et al, ).…”

Imminent extinction in the wild of the world’s largest amphibian

“…Establishing a robust status assessment for widely-distributed species requires costly, co-ordinated activities involving multiple methods, and range-wide threat assessments are therefore often extrapolated from potentially non-representative local studies [3]. The Chinese giant salamander (CGS; Andrias davidianus), the world's largest amphibian, is thought to occur across much of China, but populations are harvested to stock a farming industry supporting a new domestic luxury food market [4].…”

“…The CGS, a top predator in Chinese freshwater ecosystems, reaches 1.8 metres and represents an ancient lineage (Cryptobranchidae) that diverged >170 million years ago [3][4][5]. Endemic to China, it occupied a huge distribution across several watersheds but has declined through overexploitation and habitat loss, and is considered Critically Endangered and a global conservation priority for maintaining evolutionary history [3].…”

“…Endemic to China, it occupied a huge distribution across several watersheds but has declined through overexploitation and habitat loss, and is considered Critically Endangered and a global conservation priority for maintaining evolutionary history [3].…”

“…To assess these concerns, we conducted a four-year survey to investigate CGS status across China at sites in 97 counties selected using historical records or habitatsuitability modelling [3]. All sites contained intact habitat and diverse amphibian faunas.…”