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

Shu Chen,Zhiqiang Liang,Jian Yang,Nathalie Pettorelli,Gang Wei,Samuel T Turvey,Hanbin Xiao,Xavier A Harrison,Minyao Wu,Andrew A Cunningham,Jie Wang,Fang Yan

doi:10.1002/ece3.3862

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.

Highlights

Effective conservation management of threatened species requires a robust, evidence-based understanding of key population parameters such as geographic distribution and habitat requirements (Segan, Bottrill, Baxter, & Possingham, 2011; Stewart, Coles, & Pullin, 2005; Sutherland, Pullin, Dolman, & Knight, 2004)
Habitat suitability models are a group of mechanistic statistical models widely used in ecology, which relate the frequency of species occurrences to sets of environmental variables in order to generate predictions of locations where species are expected to occur (Franklin, 2009)
The species is severely threatened both by habitat loss and by unsustainable overexploitation of wild individuals, for the recently developed domestic luxury food market, and the rapidly growing giant salamander farming industry might further threaten its survival in the wild (Cunningham et al, 2016; Huang, 1982; Wang et al, 2004); the species may already be extirpated from areas of suitable remaining habitat. It is listed as Critically Endangered by the IUCN (2016), and it is a top priority for international conservation using prioritization metrics that incorporate evolutionary history, as it is one of only three extant species in the Cryptobranchidae, a lineage that diverged from other amphibians during the Jurassic (Isaac, Redding, Meredith, & Safi, 2012)

Summary

| INTRODUCTION

Effective conservation management of threatened species requires a robust, evidence-based understanding of key population parameters such as geographic distribution and habitat requirements (Segan, Bottrill, Baxter, & Possingham, 2011; Stewart, Coles, & Pullin, 2005; Sutherland, Pullin, Dolman, & Knight, 2004). The species is severely threatened both by habitat loss and by unsustainable overexploitation of wild individuals, for the recently developed domestic luxury food market, and the rapidly growing giant salamander farming industry might further threaten its survival in the wild (Cunningham et al, 2016; Huang, 1982; Wang et al, 2004); the species may already be extirpated from areas of suitable remaining habitat It is listed as Critically Endangered by the IUCN (2016), and it is a top priority for international conservation using prioritization metrics that incorporate evolutionary history, as it is one of only three extant species in the Cryptobranchidae, a lineage that diverged from other amphibians during the Jurassic (Isaac, Redding, Meredith, & Safi, 2012).

| METHODS

Findings

| DISCUSSION