A case study on trade in threatened Tiger Geckos (Goniurosaurus) in Vietnam including updated information on the abundance of the Endangered G. catbaensis

Changes in suitable habitat for the critically endangered Northern white-cheeked gibbon (Nomascus leucogenys) in the Western Nghe An Biosphere Reserve, Vietnam: Implication for conservation

Several recent studies have highlighted that change in land use and land cover (LULC) is the main threat causing the decline and extinction of certain species. Gibbons (Hylobatidae) could be excellent examples, on account of their potential for extinction in the near future under the effects of LULC changes due to their particular ecological traits. This study aims to model the current suitable habitat of the Northern white-cheeked gibbon (Nomascus leucogenys (Ogilby, 1840)) in the Western Nghe An Biosphere Reserve (BR), Vietnam and assess the changes in its suitable habitat following the changes in LULC from 1990 to 2020. The maximum entropy approach (MaxEnt) was used to predict the suitable habitat of the gibbon using its occurrence localities and environmental predictors. The model analysis showed that the “Distance to Agriculture” variable had the strongest impact on the gibbons’ suitable habitat. Our results predicted the present suitable habitat of the gibbon species at approximately 4,022.42 km2 (30.95% of the overall BR area) in three spatially separated areas inside the Western Nghe An BR. Furthermore, the suitable habitat areas of the gibbon in 1990, 2000, and 2010 were projected at roughly 4,347.68 km2, 4,324.97 km2, and 2,750.21 km2, respectively, following a decreasing trend from 1990 to 2010, but a gradual increase between 2010 and 2020. The suitable habitat of the gibbon inside three core protected areas (Pu Mat National Park, Pu Huong, and Pu Hoat Nature Reserves) showed a continually increasing trend from 1990 to 2020. Our results highlighted the influence of LULC changes and the role of the protected area network in gibbon conservation. The information from the study provides a quantitative baseline for the future conservation of the critically endangered gibbon in the Western Nghe An BR.

Cultural and Medicinal Use of Amphibians and Reptiles by Indigenous People in Punjab, Pakistan with Comments on Conservation Implications for Herpetofauna

Simple Summary

Humans have interacted with reptile and amphibian species for millennia. The current study was designed to collect knowledge about the use of amphibian and reptile species by the native peoples residing along the Jhelum and Chenab rivers in Punjab, Pakistan. To the best of our knowledge, this is the first quantitative assessment of the cultural uses of amphibian and reptile species in the study area. However, hunting, trade, and cultural use are the greatest threats to the diversity of the amphibians and reptiles in the studied area. These threats can potentially lead to their extinction. It is important to protect the highly endangered and vulnerable species employed in therapeutic medications, more specifically in terms of their conservation.

Abstract

Amphibians and reptiles have interacted with humans for millennia. However, humans interact with amphibian and reptile species in different manners, which depend on their culture and traditions. This study was designed to better understand the interactions between amphibian and reptile species and their usage among the native peoples in the vicinity of the Jhelum and Chenab rivers, Pakistan. Information was collected through semi-structured interviews and questionnaires, and was analyzed by using different indices, including the frequency of citation, corrected fidelity level, fidelity level, relative importance level, and informant major ailment. Two amphibians and twenty-six reptile species were used in therapeutic medicine in the study area. Based on the cultural analysis, we found that Naja naja (black cobra) was highly cited across all cultural groups. A 100% Fidelity Level was calculated for the following species: Naja naja (eye infection), Varanus bengalensis (joint pain), Eurylepis taeniolatus (cataract), and Acanthodactylus cantoris (cancer). We found five endangered species in the study area, i.e., Aspideretes gangeticus, A. hurum, Chitra indica, Varanus flavescens, and Geoclemys hamiltonii, that were used to cure joint pain, muscle stretching and pain, backbone pain, paralysis, and psoriasis, respectively. Likewise, Lissemys punctata andersoni, a vulnerable species as labelled by the International Union for Conservation of Nature, was extensively used for the treatment of joint pain, body pain, paralysis, and arthritis in the study area. In terms of conservation, it is critical to protect the highly vulnerable and endangered species that are being used in therapeutic medicines. Our findings may be helpful for the conservation of amphibian and reptile species by helping to make an effective plan to prevent their extinction. The main threats to the diversity of amphibian and reptile species in the area are hunting, trading, and cultural use. These threats could potentially lead to the extinction of these species. Therefore, with the involvement of concerned authorities, e.g., local stakeholders, the Ministry of Climate Change, provincial wildlife departments, academia, and conservation managers, immediate conservation measures should be taken for the protection and sustainable utilization of medicinal species.

Living under the risk of extinction: population status and conservation needs assessment of a micro–endemic tiger gecko in Vietnam

Human impact is considered the major threat to the global decline of biodiversity, especially for threatened endemic species in karst ecosystems. Studies assessing a species' demography based on temporal and spatial indicators of population size, density and structure are expected to evaluate the level of impact of threats and are therefore becoming increasingly important for species conservation efforts. Goniurosaurus huuliensis, an endemic species in Vietnam, is one of the most threatened reptiles in the world. This karst–adapted species is classified by the IUCN Red List as Critically Endangered and listed under CITES Appendix II due to habitat loss and over–exploitation for the international pet trade. Here we provide the first evaluation of the population status of G. huuliensis. We applied a 'capture mark–recapture' method to estimate the population size and identify the population density and structure. The total population size was estimated to comprise a maximum of 1,447 individuals in integrated suitable habitats, possibly reaching up to 2,855 individuals exclusively in karst habitats within the total extension of occurrence. This is exceedingly lower than the threshold for a minimum viable population. Furthermore, G. huuliensis is documented to occur in extremely small mean population densities of only 6.4 indiv./km and 2.5 indiv./km/day along the surveyed transects. Based on the demographic information, the ongoing severe human impact (e.g. wildlife exploitation and limestone quarrying) is driving G. huuliensis to the brink of extinction. In situ conservation measures are therefore urgently required. We recommend that in-situ actions should be increased, and a plan should be developed to establish a species and habitat conservation area for G. huuliensis.

First ecological assessment of the endangered Lichtenfelder’s Tiger Gecko (Goniurosaurus lichtenfelderi) from northern Vietnam: Micro-habitat and macro-climatic niche comparisons between island and mainland populations

The Lichtenfelder’s Tiger Gecko, Goniurosaurus lichtenfelderi is currently known only from northern Vietnam and southern China. Because of its restricted distribution, the species is potentially threatened by extinction due to anthropogenic impacts. Recently, the species has been listed in the IUCN Red List of Threatened Species as “Vulnerable” and included in CITES Appendix II and the Vietnam Governmental Decree – Group IIB. However, conservation activities to safeguard wild populations of G. lichtenfelderi have not yet been implemented due to a lack of detailed information about the population status and its ecological requirements. In this study, the micro-habitat use of G. lichtenfelderi was assessed. As a result of our field surveys, we found this species in evergreen forest areas with a high percentage of vegetation coverage and in close proximity to medium or small stream sections with rocky shelters on granitic formations. Canopy coverage, three micro-climatic variables (air, substrate temperature and humidity), weather condition and substrate type were the most important characteristics explaining the variation in the micro-habitat use of G. lichtenfelderi. Coupled with a macro-ecological (climate niche) approach, the complex niches of G. lichtenfelderi were defined by comparing them between two geographically distant populations in island and mainland sites. We found high similarities in macro-climatic and micro-habitat niches between the island and mainland populations of G. lichtenfelderi. Based on the ecological information, we recommend conservation actions to protect the core refugia of G. lichtenfelderi and reduce negative influences of anthropogenic impacts on wild populations in the future.

Ontogeny, phylogeny and mechanisms of adaptive changes in evaporative water loss in geckos

Body size dependence of metabolic rate, body surface and scale morphology complicate disentangling the contribution of these characteristics to adaptive changes in total evaporative water loss (TEWL) of reptiles. To separate adaptive changes from size-related dependence, we compared intra- and interspecific scaling of several candidate traits in eyelid geckos (Eublepharidae), a group exhibiting large variation in body size and TEWL. The intraspecific allometry of TEWL of a eublepharid species fits the geometric surface-mass relationship. However, evolutionary shifts to both higher and lower evaporation were strongly correlated with habitat aridity and cannot be explained by shifts in body size alone. The intraspecific allometry of standard metabolic rate is nearly the same as the interspecific allometry. Unlike for mammals and birds, this pattern rules out respiratory water loss as a driver of the adaptive changes in TEWL among eublepharids. Scale morphology was independent of TEWL variation as well, but the correlation between cutaneous water loss and TEWL suggests a crucial role of skin permeability in adaptation to habitat aridity. Our analyses demonstrate how powerful a comparison between intra- and interspecific allometries can be for detecting body size-dependent mechanisms of adaptive changes in ecophysiological traits correlated with body size.

Slow life history leaves endangered snake vulnerable to illegal collecting

Global wildlife trade is a multibillion-dollar industry and a significant driver of vertebrate extinction risk. Yet, few studies have quantified the impact of wild harvesting for the illicit pet trade on populations. Long-lived species, by virtue of their slow life history characteristics, may be unable to sustain even low levels of collecting. Here, we assessed the impact of illegal collecting on populations of endangered broad-headed snakes (Hoplocephalus bungaroides) at gated (protected) and ungated (unprotected) sites. Because broad-headed snakes are long-lived, grow slowly and reproduce infrequently, populations are likely vulnerable to increases in adult mortality. Long-term data revealed that annual survival rates of snakes were significantly lower in the ungated population than the gated population, consistent with the hypothesis of human removal of snakes for the pet trade. Population viability analysis showed that the ungated population has a strongly negative population growth rate and is only prevented from ultimate extinction by dispersal of small numbers of individuals from the gated population. Sensitivity analyses showed that the removal of a small number of adult females was sufficient to impose negative population growth and suggests that threatened species with slow life histories are likely to be especially vulnerable to illegal collecting.

The Rush for the Rare: Reptiles and Amphibians in the European Pet Trade

Simple Summary

The exotic pet trade has been identified as a main threat to many reptile and amphibian species, especially for optically attractive species or those with special biological features. The international exotic pet trade is largely unregulated and in large parts still heavily depends on wild-caught specimens. Rarity sells, and species that are new to science or new on the pet market are highly sought-after and may fetch record prices. The European Union is a main hub and destination for both legally and illegally sourced wildlife. In the German town Hamm, one of the largest reptile trade shows in the world takes place four times a year, attracting traders and clients from across Europe and beyond. Based on ten case studies, our article illustrates marketing mechanisms and trade dynamics for reptiles and amphibians, which have only recently been described by science. The paper also highlights the problems of insufficient international legislation to prevent over-exploitation of such species or even those which are nationally protected in their country of origin, and presents solutions.

Abstract

Direct exploitation is one of the five main reasons for the loss of biodiversity, and collections for the international pet trade are an ongoing threat for many reptiles and amphibians. The European Union and in particular Germany have a central role as a hub and destination for exotic pets from all over the world. Rare species of reptiles and amphibians especially are in the focus of collectors. Rarity on the market may be either caused by rarity of a species in the wild or by a limited availability for sale, e.g., due to national protection measures in the range state or remote localities. The present study identified 43 species that are not listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and were only recently described, but have already entered the European pet trade. Ten of these species were selected as case studies, representing species from different geographic regions and illustrating the marketing mechanisms. Many such species that are new to science are neither assessed by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species nor are they covered by international legislation, even though in several countries, where such internationally sought-after species are caught, national protection measures are in place. This paper analyses the challenges and opportunities for the protection of potentially threatened and newly described reptile and amphibian species against over-exploitation for the pet trade.