Chinese giant salamanders 379
survey sites reported hunting the species, with these figures likely to be underestimates of true hunting levels as a result of the sensitive and illegal nature of this activity. Even if re- spondents did not hunt giant salamanders themselves, they often reported that other people from outside their commu- nity hunted salamanders locally. The prevalence of illegal overexploitation is further demonstrated by direct evidence of ongoing poaching of giant salamanders observed by field teams at over a quarter of our survey sites. Although observed illegal fishing activities could also be targeting other aquatic species, the methods deployed are non-species specific and could result in capture, death or injury of giant salamanders. The Chinese giant salamander complex comprises at
least three species, including the recently described South China giant salamander A. sligoi (Yan et al., 2018; Liang et al., 2019; Turvey et al., 2019). The ecological survey meth- ods deployed in this study have been successfully used to de- tect other cryptobranchid salamander species in both Japan and the USA (Browne et al., 2011), and therefore it is unlikely that the existence ofmultiple giant salamander species across our survey region confounds our results, or that different giant salamander species differ in their susceptibility to hunt- ing. Speciation of Andrias in Chinawas associatedwith uplift of the Qinghai–Tibet Plateau and geographical isolation of populations in different montane ecoregions rather than with niche differentiation (Turvey et al., 2019), and giant sal- amanders are likely to be generalist species with respect to their macrohabitat and microhabitat requirements. Hybrids between Chinese giant salamanders and Japanese giant sala- manders (Andrias japonicus) are now invasive in parts of Japan (Fukumoto et al., 2015), and wide-scale intentional releases of giant salamanders across China has resulted in genetic homogenization of some local populations (Yan et al., 2018). Other possible factors could also have driven the observed
range-wide decline of Chinese giant salamanders. Disease is known to cause significant mortality on giant salamander farms in China (Geng et al., 2011;Menget al., 2014) and effluent from farms is discharged into river systems without treatment across the range of Chinese giant salamanders (Cunningham et al., 2016). Furthermore, the widespread practice of releasing farmed salamanders into rivers across China is not informed by pathogen screening (Cunningham et al., 2016), and pathogen pollution could constitute a potential risk to wild populations.We were un- able to quantify the potential impact of the farming industry on the health of wild populations, but the presence of diverse amphibian species communities, including other salamander species, at most of our survey sites further indicates that dis- ease is not likely to be a primary driver ofwild giant salaman- der population declines. Our investigation of environmental parameters associ- ated with giant salamander presence and absence in China
provides a new evidence-base to guide conservation plan- ning for this Critically Endangered species complex of the largest amphibians. It appears likely that giant salamander populations have been largely extirpated across our sur- veyed sites by poaching rather than habitat degradation. This highlights the pressing need for existing protective legislation prohibiting the hunting of giant salamanders to be better implemented and more strictly enforced, together with strict habitat protection, if Chinese giant salamanders are to persist in the wild. Our increased knowledge of the environmental condi-
tions under which giant salamanders occur is invaluable for informing ex situ conservation breeding programmes, which have been suggested as a necessary component of the conservation strategy for Chinese giant salamanders (Turvey et al., 2018, 2019). A robust understanding of the environmental requirements of the target species is a prerequisite for the establishment of captive breeding pro- grammes (Michaels et al., 2014). To our knowledge, there are no existing Chinese giant salamander captive breeding programmes that can produce offspring suitable for sub- sequent release into the wild. Although Chinese giant salamanders have been bred to several generations on com- mercial breeding farms, the often unknown provenance of founding stock, presence of multiple pathogens, and often suboptimal biosecurity makes farms inappropriate for con- servation breeding (Cunningham et al., 2016). Our water parameter data should therefore be used to inform the development of husbandry protocols and water quality management for Chinese giant salamander conservation breeding programmes in dedicated conservation breeding facilities in China. These data have already been used suc- cessfully for the management of an ex situ population of Andrias davidianus at the Zoological Society of London. We hope that stakeholders and decision makers in China will act upon our findings and will strengthen both in situ and ex situ conservation actions for giant salamanders while there is still time to save these remarkable species.
Acknowledgements We thank all of the field assistants for partici- pating in surveys. Funding was provided by the Darwin Initiative (Project No. 19-003), the National Natural Science Foundation of China (31360144), Ocean Park Conservation Foundation Hong Kong, and the Zoological Society of London’s EDGE of Existence programme.
Author contributions Study design, data collection, writing; BT, STT, AAC; coordination of field activities, study design, data collec- tion: SC; study design, data collection: SO, JR, GW, FX, MW, JC; data collection: JY, ZL, HT, JW, JL, FZ, HZ, JX, TB.
Conflicts of interest None.
Ethical standards This study adhered to the code of ethics developed and endorsed by the British Sociological Foundation. All methods, including a biosecurity protocol to prevent the spread of pathogens be- tween sites, were approved by the Zoological Society of London’s Ethics Committee and comply with the Oryx guidelines on ethical standards.
Oryx, 2021, 55(3), 373–381 © The Author(s), 2021. Published by Cambridge University Press on behalf of Fauna & Flora International doi:10.1017/S0030605320000411
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