Research Article
Print
Research Article
Assessment of the threat status of the amphibians in Vietnam - Implementation of the One Plan Approach
expand article infoMarie Krzikowski, Truong Q. Nguyen§|, Cuong T. Pham§|, Dennis Rödder, Anna Rauhaus#, Minh D. Le¤«», Thomas Ziegler#
‡ University of Cologne, Cologne, Germany
§ Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| Graduate University of Science and Technology, Hanoi, Vietnam
¶ Museum Koenig Bonn, Bonn, Germany
# Cologne Zoo, Cologne, Germany
¤ University of Science, Hanoi, Vietnam
« Vietnam National University, Hanoi, Vietnam
» American Museum of Natural History, New York, United States of America
Open Access

Abstract

The current decline in global biodiversity is most evident in amphibians with 41% percent of all species worldwide classified as threatened with extinction. Hence, a major challenge in amphibian conservation is the high number of threatened species, leading to a common approach of identifying priority species and regions for conservation efforts. As a part of one of 36 globally designated biodiversity hotspots, Vietnam is considered to be of particular importance for conservation action. To improve amphibian conservation in Vietnam, this study provides an updated species list and assesses their threat status by compiling data from a variety of sources. Furthermore, a Zoological Information Management System (ZIMS) analysis was conducted to determine the representation of extant amphibians from Vietnam in zoos worldwide. The batrachofauna of Vietnam is characterized by a high level of species richness and local endemism as well as a high rate of new discoveries, with more than half of the endemic species reported exclusively from their type locality, making them especially vulnerable to extinction. Up to 18% of all amphibians extant in Vietnam and 28% of endemic species are classified as threatened with extinction by the IUCN. In many cases, the IUCN Red List status is either missing or outdated, highlighting the urgent need of action. Around 14% of endemic amphibian species have been recorded exclusively from unprotected areas, suggesting prioritization for further research and conservation measures. The continuing decline in many species remains an unresolved problem. As a guide for future research and conservation measures, a list of the top 57 species was compiled. In addition, according to the ZIMS analysis, only 8% of threatened and 3% of endemic amphibian taxa from Vietnam are currently kept in zoos worldwide, and a richness analysis revealed that the highest density of husbandries is found in Europe and North America. To achieve maximum outcome for the conservation of threatened species, this study recommends a general shift by zoos towards maintaining species in greater need of captive assurance populations and breeding programs to support integrative strategies that combine in situ and ex situ conservation efforts following the IUCN’s One Plan Approach.

Keywords

Amphibian conservation, conservation breeding, diversity analysis, endemic species, protected area coverage, threatened with extinction

Introduction

As a profound consequence of humankind’s global impact on the natural environment, a biodiversity crisis is currently taking place (Wake and Vredenburg 2008; Tollefson 2019; Melville et al. 2021). This rapid biodiversity decline is most evident in amphibians (Gascon et al. 2007; Bishop et al. 2012; Clulow et al. 2014), of which currently more than 40% of all species in the world are under the risk of extinction (IUCN 2021). Amphibians are considered particularly vulnerable to changes, as many species have narrow habitat preferences and restricted geographic ranges (Purvis et al. 2000; Wake and Vredenburg 2008). They also occupy environments that are subject to a multitude of primarily human-caused drivers of decline (Pabijan et al. 2020).

Major threats to the amphibian species are habitat degradation and fragmentation, introduction of invasive species, over-exploitation, and climate change (Gascon et al. 2007; Halliday 2008; Bishop et al. 2012; Hussain and Pandit 2012; Meredith et al. 2016). Additionally, amphibians have been affected by the pathogenic fungi Batrachochytrium dendrobatidis and B. salamandrivorans which can induce chytridiomycosis (Kilpatrick et al. 2010; Martel et al. 2013). This disease has already been linked to the extinction of several amphibian species (Schloegel et al. 2006; Vredenburg et al. 2010). Decreasing amphibian populations are of particular concern because they are indicators of environmental stress and ecosystem health (Blaustein and Wake 1995; Welsh and Ollivier 1998; Bishop et al. 2012). Their precipitous decline serves as a warning that we are in a period of significant environmental degradation (Baillie et al. 2004). Amphibians are integral components of many ecosystems on every continent except Antarctica and may represent an important link between aquatic and terrestrial ecosystems (Whiles et al. 2006). Being predators, prey, or herbivores, and thus contributing to the trophic dynamics of many communities, the loss of amphibians is likely to have cascade impacts on other species (Blaustein 1994; Blaustein and Kiesecker 2002). Therefore, the severe amphibian declines demand urgent and collective actions to prevent another large-scale species extinction (Isaac et al. 2012; Pabijan et al. 2020).

The disappearance of amphibians is perhaps the most significant taxon-specific extinction event that conservationists are facing (Zippel et al. 2011). A major challenge in amphibian conservation is the high number of species facing extinction worldwide, as it far exceeds the resources available (Mittermeier et al. 1998; Myers et al. 2000; Mittermeier et al. 2011). Therefore, scientists are facing hurdles in determining the best approach to save the maximum number of species with the available resources and identifying which species should be prioritized initially (Myers et al. 2000). Since habitat loss is a key threat to nine out of ten threatened amphibian species (Baillie et al. 2004), it is important to identify, safeguard, and possibly extend protection, especially for sites where high rates of threatened species occur (Semlitsch 2003). Furthermore, endemic species with restricted ranges are more at risk of extinction than those with larger ranges (Meiri et al. 2017). Thus, biodiversity hotspots with high concentrations of endemic and threatened species need to be identified (Myers 1990; Mittermeier et al. 1998; Eken et al. 2004). Additionally, in cases where over-exploitation, habitat loss or pollution is the clear driver of extinction, captive assurance colonies need to be held in suitable programs, such as in zoos or conservation breeding stations, so that habitat restoration efforts and reintroductions can be a viable conservation strategy (Clulow et al. 2014).

Vietnam is located in the Indo-Burma region, one of the 36 global biodiversity hotspots, which constitute focal points for conservation efforts (Myers et al. 2000; Stork and Habel 2014; Noss et al. 2015). Due to an excessive rate of habitat loss and a large number of endemic species, Vietnam is regarded as an important area with high biodiversity conservation priority (Myers et al. 2000). In terms of biodiversity, the country is recognized as one of the top nations in the world with high species richness (Sterling et al. 2006), particularly the herpetofauna (Adler 2009). An extraordinarily large number of new species has been described from Vietnam in the last decades, in particular amphibians and reptiles (e.g., Ziegler and Nguyen 2019, see below).

The first major herpetological summary was published by Morice (1875), listing 13 amphibian species for Vietnam. From 1947, Rene Bourret published a series of papers and books on the herpetofauna of Vietnam, Laos, and Cambodia, documenting a total of 171 amphibians for the Indochinese region (Nguyen 2006). Because of the Indochinese Wars, biodiversity exploration was interrupted during the period from 1954 to 1975. Since 1975, a surge in herpetological studies of Vietnam has resulted in an enormous increase of our knowledge in this group of vertebrates (Nguyen 2006). The most recent herpetological list for Vietnam by Nguyen et al. (2009) reported 174 species of amphibians. Moreover, a large number of new amphibian discoveries from Vietnam in the last three decades also highlighted the mega-diversity of the country (Ziegler and Nguyen 2019). The outcomes of the studies and the resulting greater knowledge of the batrachofauna of Vietnam are essential for species conservation, as these data form a foundation for developing effective conservation programs.

In terms of nature conservation, the most important policy of Vietnam was the establishment of a protected area network. In 1962, the first Vietnamese National Park (NP), Cuc Phuong NP, was established in northern Vietnam. Three decades later, in 1995 with the ongoing loss of habitat and over-exploitation of the fauna and flora, the government decided to counteract by expanding the network of existing NPs and protected areas (PAs) (Sterling et al. 2006). Since then, the number of PAs has increased to a total of 33 NPs, 59 nature reserves, and 13 habitat and species conservation areas in Vietnam, including two world heritage sites (Stolton et al. 2004; Le et al. 2018, VEA 2020). With 1,077,236 ha in total, the NPs cover about 3% of the country’s area and there are plans to increase this number even further. Of the current 33 NPs, 24 are managed by provincial authorities, while the Vietnam Administration of Forestry (VNFOREST) is responsible for the other six (Le et al. 2018).

As there is no conservation assessment of endemic and threatened terrestrial vertebrate species in Vietnam available, this study focuses on amphibians. As a basis for improved conservation of Vietnamese amphibians, we analyzed the species diversity of amphibians in the country, their threat status according to IUCN (2021), national legislations as well as their distribution with particular focus on endemic and micro-endemic species. Considering the One Plan Approach, supported by the IUCN, that aims to develop integrative strategies to combine in situ and ex situ measures with groups of experts for the purpose of improved species conservation, another goal of this study was to analyze the representation of extant amphibian species from Vietnam in zoos worldwide. Such an approach has already been performed for amphibians globally (Jacken et al. 2020), but not yet for a particular region in Southeast Asia. As this study presents a topical review of the amphibian fauna of Vietnam, the first objective was to provide an updated species list for all amphibian species extant in Vietnam. We further identified hotspots based on species-level metrics (e.g., species richness, endemism, and extinction vulnerability). We assessed the proportion of endemic and threatened species, and the coverage of their distribution areas by protected areas to compile a list of the taxa, which face the greatest risk of extinction and hence are in highest need of attention in conservation work.

Methods

Species list

To identify which amphibians occur in Vietnam, the most recent list published by Nguyen et al. (2009) was used as an initial starting point. To document species records in Vietnam after 2009 and any taxonomic revisions, we searched the online databases, e.g., Amphibian Species of the World (Frost 2021) and Amphibia Web (2021). Data collection for this study was conducted between May and June 2021. Species record was verified case by case and the cut-off date was set to 30th June 2021. Data obtained from ZIMS was updated on the 20th of March 2022.

Distribution

Distribution data followed Nguyen et al. (2009) and were augmented by online databases, Amphibian Species of the World (Frost 2021) and Amphibia Web (2021), the IUCN Red List (IUCN 2021) and the following publications: Ohler et al. (2000, 2011), Ohler and Grosjean (2005), Bain et al. (2003, 2007, 2009a-b), Bain and Nguyen (2004), Nguyen et al. (2005, 2008, 2013, 2014a-b, 2016, 2018a-b, 2020a-b), Orlov et al. (2006, 2012), Orlov (2008), Hendrix et al. (2008), Dubois and Ohler (2009), Rowley and Cao (2009), Rowley et al. (2011a-b, 2012a-b, 2013, 2014, 2015, 2016, 2017, 2020), Matsui et al. (2010), Tran et al. (2010), Stuart et al. (2011), Chan et al. (2013), Luu et al. (2013), Milto et al. (2013), Nishikawa et al. (2013), Ostroshabov et al. (2013), Le et al. (2014, 2015a-b, 2021a), Le and Do (2019), Pham et al. (2014, 2015, 2016a-b, 2017a-c, 2018a-b, 2019a-d, 2020a-d), Ziegler et al. (2014), Vassilieva et al. (2014, Geissler et al. (2015), McLeod et al. (2015), Gawor et al. (2016), Poyarkov et al. (2017, 2018a-c, 2021a), Yu et al. (2017, 2019a-b), Chen et al. (2018), Duong et al. (2018), Sheridan and Stuart (2018), Tapley et al. (2018), Kropachev et al. (2019), Luong et al. (2019, 2021), Bernardes et al. (2020), Cutajar et al. (2020), Ninh et al. (2020), Ong et al. (2020),Wu et al. (2020), Gorin et al. (2021), Hoang et al. (2021), Tran and Le (2021), and Zheng et al. (2021).

Species endemic to the Indochinese Region and Vietnam were determined following the definition by Bain and Hurley (2011) of the Indochinese Region as containing three countries, Cambodia, Laos, and Vietnam. Further investigations into whether endemic species in Vietnam are restricted to a local, provincial, regional or macro-regional level, and how wide their distribution areas cover within the country, were carried out. We used geographic regions and administrative units of Vietnam as measures of distribution areas (Fig. 1, Suppl. material 1: Table S10).

Figure 1.

Number of recorded amphibian species per province and region. Map of Vietnam with its eight regions, 58 provinces, and five municipalities and the respective number of recorded amphibian species per province and per region (see respective references in Material and Methods). Adopted and modified from IEBR archive.

Following the compilation of distribution ranges of all amphibians extant in Vietnam, the protected area coverage of micro-endemic species was assessed. The localities of the species were obtained from the sources listed above and were plotted on PAs maps using software package QGIS 3.18.3 (QGIS Development Team 2021).

Subregions of Vietnam

Vietnam is located in the Northeast of mainland Southeast Asia. It stretches along the eastern edge of the Indochinese Peninsula to the Gulf of Thailand and borders the southern Chinese provinces of Yunnan and Guangxi to the North and the Lao People’s Republic to the West. The southern part of the country borders Cambodia and maintains maritime borders with Thailand, the Philippines, Indonesia, and Malaysia. In terms of administration, there are 58 provinces in Vietnam, as well as five centrally administered cities called municipalities (Sterling et al. 2006). Geographically, two fertile river deltas lie in the North and South, with a narrow strip of forests and mountains in between as a link. In total, Vietnam covers a land area of 330,591 km2. Vietnam’s climate is subtropical with four seasons in the North and tropical with a dry and a rainy season in the South. On the high plateaus in central Vietnam, the temperature is generally lower and the climate more humid, with dry seasons typically lasting only three months (Sterling et al. 2006).

This study followed Sterling et al. (2006) in dividing the country into eight geographic regions and three macro-regions, northern, central, and southern Vietnam. Northern Vietnam consists of three regions, Northwest (NW), Northeast (NE) and Red River Delta (RRD). Central Vietnam also contains three regions, North Central (NC), South Central Coast (SCC) and the Central Highlands (CH). The remaining two regions, Southeast (SE) and Mekong River Delta (MRD), form the third macro-region, southern Vietnam. The regions vary in their geography, biogeographic history, and climate, which have shaped different flora and fauna communities (Sterling et al. 2006).

Threat status

Information on the threat status of each species was first retrieved from the IUCN Red List of Threatened Species (IUCN 2021) which allocates taxa to one of nine IUCN Red List Categories: Not Evaluated (NE), Data Deficient (DD), Least Concern (LC), Near Threatened (NT), Vulnerable (VU), Endangered (EN), Critically Endangered (CR), Extinct in the Wild (EW), and Extinct (EX). Those rated VU, EN and CR were classified as threatened with extinction (IUCN 2021). The IUCN aims to update the extinction risk assessments of each species at least every 10 years, as the IUCN status is considered invalid 10 years after its publication.

To further determine threat statuses of each species, the inclusion of species in the three appendices of CITES (Convention on International Trade in Endangered Species of Wild Flora and Fauna) was reviewed (CITES 2021a). Vietnam joined CITES in 1994 (CITES 2021b).

After checking their listings in the international regulations, species in the Vietnam Red Data Book and in the appendices of national decrees were documented. At the national level, species in Vietnam are under protection by the Governmental Decree No. 64/2019 and Decree No. 06/2019. The former lists species with the highest conservation priority, whereas the latter lists threatened and rare forest-dwelling species that are protected by law. Furthermore, Decree No. 06/2019 is designed to implement CITES at the national legislative level, thus including species listed in CITES appendices. In addition to these two decrees, threatened species are catalogued in the Vietnam Red Data Book, with the latest version published in 2007 (Tran et al. 2007). This version is outdated; however, scientists at the Institute of Ecology and Biological Resources are presently working on a new edition. Generally, the Vietnam Red Data Book is based on the IUCN Red List criteria and uses the IUCN categories. If a species is not endemic to a country, the threat classifications for national populations in the National Red List may differ from those assessed by the IUCN (IUCN 2021).

Ex situ populations

Regarding the representation of Vietnamese amphibians in zoos worldwide, data on the species and the number of individuals held in registered collections as well as the number of institutions keeping extant amphibians in Vietnam was obtained via the Zoological Information Management System (ZIMS 2022). In a second step, we quantified how many amphibian species extant in Vietnam are represented in zoos worldwide and the respective proportions of endemic and threatened species. ZIMS is a web-based, real-time data collection system which captures both animal husbandry and medical information (ZIMS 2022). It allows zoo and aquarium staff members to enter, check, and revise animal records from zoos globally. The software contains data on gender distributions as well as reports of successful reproduction within the last 12 months. Participation in ZIMS is not mandatory for zoos and not all zoos have added their collection data to the system. Thus, to analyze additional holdings, we further searched the website “Zootierliste” (ZTL, Zoo Animals’ list) (Graf et al. 2021). This database contains information on the current and former animal holdings of European zoos and other public animal husbandries which are entered by registered users. The ZTL does not contain information on the number of individuals of the different species kept in zoos and their breeding success. Only the number of keeping institutions obtained via the ZTL database are represented in this study to get a most complete species inventory.

For non-endemic taxa, if those known to occur in Vietnam are listed in ZIMS or ZTL, they do not necessarily derive from the country, as founders of the captive population may come from other range states.

Diversity analysis

The geographic distribution of holdings, including their covered diversity was assessed in R based on the coordinates of the relevant zoos obtained from ZIMS. The total number of zoos per country, the number of individuals per species kept in each zoo and Shannon-Weaver Index (H = -∑ pi log(b) pi) were computed using package Vegan (Oksanen et al. 2020). In this index, pi refers to the proportion of species i and log(b) is the natural logarithm.

Results

Amphibian diversity

Of the 174 amphibian species listed for Vietnam by Nguyen et al. (2009), 154 species were incorporated in the species list. The other 20 species (18 frog species and 2 salamander species) were excluded, either because they are no longer considered to be extant in Vietnam, because populations in Vietnam have been assigned to a different species, or because they are junior synonyms of other species (see references in Suppl. material 1: Table S1). Additionally, a total of 48 species have been assigned to new genera and one additional species has been removed from its last accepted genus but has not yet been assigned to a new genus (Suppl. material 1: Table S2). Moreover, a total of 86 species have been newly described from Vietnam since Nguyen et al. (2009) (Suppl. material 1: Table S3). One additional species, namely Amolops daorum, was described from Vietnam by Bain et al. (2003) prior to the species list by Nguyen et al. (2009) but was considered a junior synonym of A. mengyangensis by Ohler (2007). However, this hypothesis was rejected by Stuart et al. (2010), leading to the inclusion of Amolops daorum in the amphibian species list of Vietnam presented in this study. Additionally, 34 new country records for Vietnam (Suppl. material 1: Table S4) have been added to the final species list of this study, consisting of a total of 275 amphibian species for Vietnam (Suppl. material 1: Table S5) or 3,3% of the global amphibian diversity. All three orders of amphibians are represented, including 3.6% of the Anura, 1% of the Caudata, and 1.9% of the Gymnophiona (Table 1). All of the species belong to 53 genera and most species fall within the order Anura (n = 263 or approximately 96%), while the rest are members of the order Caudata (n = 8 or nearly 3%) and the order Gymnophiona (n = 4 or more than 1%) (Table 1).

Table 1.

Number of Vietnamese amphibians compared to the global amphibian diversity. Data for the global amphibian species richness was retrieved from the Amphibian Species of the World (Frost 2021).

Order Worldwide Vietnam Vietnamese endemics
Anura 7361 263 88
Caudata 766 8 5
Gymnophiona 213 4 2
Total 8340 275 95

In Vietnam, the order Anura contains eight families, Caudata and Gymnophiona contain only one family each. In the order Anura, Rhacophoridae is the most diverse family with 75 recorded species. The family Salamandridae is the unique representative of the order Caudata in Vietnam, with eight members belonging to one subfamily. The family Ichthyophiidae, a member of the order Gymnophiona, is represented with four species. The ten most speciose genera account for 55% of all amphibians in the country and are listed in Table 2.

Table 2.

Ten most speciose genera of amphibians in Vietnam.

Genus Number of species Subfamily Family Order
Leptobrachella 27 Leptobrachiinae Megophryidae Anura
Odorrana 24 Ranidae Anura
Amolops 15 Ranidae Anura
Rhacophorus 15 Rhacophorinae Rhacophoridae Anura
Theloderma 15 Rhacophorinae Rhacophoridae Anura
Microhyla 14 Microhylinae Microhylidae Anura
Leptobrachium 11 Leptobrachiinae Megophryidae Anura
Gracixalus 11 Rhacophorinae Rhacophoridae Anura
Limnonectes 10 Dicroglossinae Dicroglossidae Anura
Panophrys 10 Megophryinae Megophryidae Anura

Distribution

The diversity of local amphibian faunas differed among the geographic regions and provinces of Vietnam (Fig. 1). The highest species diversity among the eight regions was recorded for the Central Highlands (130 species), Northwest (121 species), North Central (112 species) and Northeast (110 species). Regarding the species richness per province, the ten provinces with the highest number of species were Lao Cai (92 species), Gia Lai (84 species), Kon Tum (76 species), Son La (65 species), Lam Dong (64 species), Thua Thien-Hue (64 species), Ha Giang (60 species), Dak Lak (59 species), Quang Binh (57 species), and Ha Tinh (56 species) (Fig. 1). Table 2 shows the similarities between the different amphibian faunas of the eight regions. Species similarity based on Sørenson’s similarity index varied from 0.22 to 0.64 between the regions. The highest similarity between the regions of Vietnam was found between Northwest and Northeast with a similarity index value of 0.64. Overall, it was shown that regions of the same macro-region appeared more ecologically similar to each other (similarity index value > 0.5) than to regions of other macro-regions (similarity index value ≤ 0.5), which shared fewer species. An exception to this was the Red River Delta region of the North macro-region, whose species composition was only 0.34 similar to that of the Northwest region (Table 3).

Table 3.

Species similarity (measured by Sørenson index) between eight geographic regions of Vietnam.

Region NW NE RRD NC SCC CH SE MRD
NW 1 0.64 0.34 0.54 0.3 0.35 0.35 0.22
NE 1 0.61 0.54 0.29 0.35 0.36 0.23
RRD 1 0.55 0.36 0.41 0.5 0.32
NC 1 0.59 0.57 0.42 0.24
SCC 1 0.6 0.47 0.26
CH 1 0.53 0.25
SE 1 0.55
MRD 1

Endemism

Approximately 49.1% of the recorded species (135 of 275) of amphibians in Vietnam are endemic to the Indochinese Region. The proportion of the country endemism is 34.5% (95 of 275 species). In percentage terms, 93% of the endemic species from Vietnam belong to the order Anura (n = 88), 5% to the Caudata (n = 5), and 2% to the Gymnophiona (n = 2) (Table 1). More than half of all endemic species are members of the anuran families Megophryidae (n = 28) and Rhacophoridae (n = 28) (56 out of 95 species or 59%) (see in Suppl. material 1: Table S4 for more information).

More than half of all endemic amphibian species from Vietnam are reported exclusively from their type locality (n = 54) (Fig. 2). One species, namely Oreolalax sterlingae, occurs in multiple locations in a single province. Another 12 species are distributed in between two and four provinces in one region. One-fifth of all endemic taxa are regionally widespread (n = 20) occupying from two to nine provinces in two or three regions. Macroregional endemism is known for four species, while three species inhabit areas in six or more provinces in two macro-regions and are classified as widespread. Only Microhyla picta has been reported in all three macro-regions.

Figure 2.

Distribution range of endemic amphibians from Vietnam (n = 95). Records separated according to the size of the area where the species is recorded. Distributions are described as follows: local - type locality only; provincial - multiple locations in one province; regional - 2–4 provinces in same region; regionally widespread - 2–9 provinces in 2–3 regions of the same macro-region.

Regarding the distribution among the three macro-regions, 87 species are endemic to one of them: 33 species to northern Vietnam, 53 species to central Vietnam, and 1 species to southern Vietnam (Suppl. material 1: Table S6). Another seven species are endemic to two adjacent macro-regions, either the North and the Central or the Central and the South. About 70% (67 out of 95 endemic species) are recorded exclusively from one region (Fig. 3).

These 67 regional endemic species consist of 61 frog species, four salamander species, and two caecilian species (Suppl. material 1: Table S7). The Central Highlands, with 39% species endemic to this region, contain the most regionally endemic amphibians (n = 26), followed by NE (n = 14 or 21%), and NW (n = 11 or 16%) (Fig. 3).

Figure 3.

Distribution of regionally endemic amphibian species in Vietnam. Map of Vietnam with its eight geographic regions and the respective number of regional endemics per region. Adopted and modified from IEBR archive. (See Suppl. material 1: Table S8 for more details related to the distribution of regional endemic species).

Four-fifths of all regional endemic species occur in one province only (55 of 67 species) and are therefore classified as local endemics (Fig. 4).

Figure 4.

Distribution of provincially endemic amphibian species in Vietnam. Map of Vietnam with its 58 provinces and five municipalities and the respective number of provincially endemic amphibian species in bold. The number in brackets indicates the total number of endemic amphibian species from Vietnam for the province including the provincial endemics. Adopted from IEBR archive.

Further data about the differences in the distribution of endemic species belonging to the orders Anura, Caudata and Gymnophiona is presented in Suppl. material 1: Table S9. All endemic Gymnophiona species (two of two endemic species) are endemic at the provincial level, as well as 58% of endemic anuran species (n = 51) and 40% of endemic Caudata species (n = 2) (Fig. 4 and Suppl. material 1: Table S10).

Threat status

IUCN Red List status

A total of 203 species were included in the IUCN Red List (IUCN 2021), representing 73.8% of all amphibians extant in Vietnam. A quarter (or 72 species) known from Vietnam have not been assessed by the IUCN Red List, comprising 67 species of the order Anura, three of the order Caudata and two of the order Gymnophiona (Fig. 5).

Figure 5.

Listing of amphibian species extant in Vietnam on the IUCN Red List (IUCN 2021).

In percentage terms, 25% of all Vietnamese amphibians assessed by the IUCN are considered threatened with extinction (50 out of 203 available statuses; CR = three species, EN = 25 species, VU = 22 species) (Fig. 6A). Based on absolute numbers, frogs are most threatened (n = 47), salamanders are second most threatened (n = 3), and caecilians are not considered threatened with extinction (n = 0) (Fig. 6B–D). In terms of the relative proportions of threatened and non- threatened species within the orders, salamanders are the most threatened, with 60% of the listed species classified as threatened with extinction, frogs are the second most threatened taxon with 24% of the species listed as threatened and caecilians are listed as non-threatened with 100% classified as LC. Approximately one sixth of all frogs are currently classified as DD. More than half of all species conservation statuses (104 out of 203 available statuses) are older than 10 years and therefore no longer valid. IUCN Red List status is outdated for 79% of all species classified as DD (26 out of 33 species), for 20% of the total 50 species classified as threatened (VU: 5 out of 22 species, EN: 5 out of 25, CR: 0 out of 3) and for 85% of the species classified as NT (11 out of 13).

Figure 6.

Distribution of IUCN Red List statuses of the Vietnamese amphibian taxa for which a status was available. A all orders B Anura C Caudata D Gymnophiona (IUCN 2021).

Up to 44 country endemic species are included in the IUCN Red List, representing 46% of all amphibian species endemic to Vietnam. For 51 endemic species recorded from Vietnam, no IUCN Red List status is available. For 30% of the assessed species, insufficient data is available, and they are classified as DD (n = 13). Of the remaining 31 species, 87% are classified as threatened with extinction (n = 27) (example species presented in Fig. 7), and 13% as LC (n = 4). While endemic species evaluated by the IUCN constitute only 22% of all evaluated species, they contribute to 67% of all CR species, 68% of all EN species, and 41% of all VU species. Regarding the distribution of endemic species (n = 95) and their IUCN Red List status, 63% of threatened species (17 out of 27 threatened species, EN: 11; VU: 6) are endemic to central Vietnam. Another 30% (CR: 2; EN: 4; VU:2) of threatened taxa are endemic to northern Vietnam, while no species endemic to southern Vietnam are classified as threatened with extinction by the IUCN (Suppl. material 1: Table S11).

Figure 7.

Threatened endemic amphibian species from Vietnam A Oreolalax sterlingae (IUCN: CR) B Leptobrachium ngoclinhense (IUCN: EN) C Amolops minutus (IUCN: EN) D Rhacophorus vampyrus (IUCN: EN) (Photos: T. Q. Nguyen and C. T. Pham).

Considering the regional endemic species, 67% have not been evaluated by the IUCN (n = 45), 6% are classified as DD (n = 4) and 27% are considered threatened with extinction (n = 18; CR: 2; EN: 12; VU: 4). Among species classified as threatened with extinction, 11 species are endemic to the Central Highlands region, four species to the Northeast and three species to the Northwest (Table 4).

Table 4.

Distribution of amphibian species from Vietnam endemic to one region (n = 67) and their IUCN Red List status.

Region IUCN (2021) Not Evaluated Total
CR EN VU NT LC DD
Northwest 2 1 0 0 0 0 8 11
Northeast 0 2 2 0 0 2 8 14
Red River Delta 0 0 0 0 0 0 3 3
North Central 0 0 0 0 0 0 6 6
South Central Coast 0 0 0 0 0 0 6 6
Central Highlands 0 9 2 0 0 2 13 26
Southeast 0 0 0 0 0 0 1 1
Mekong River Delta 0 0 0 0 0 0 0 0
Total 2 12 4 0 0 4 45 67

Regarding the threat statuses of local endemic species, no status was available for species belonging to the orders Caudata (n = 2) and Gymnophiona (n = 2) and for two-thirds of the in total 51 local endemic species belonging to the order Anura (n = 34). Of the 17 species for which a status was available, 13 species were classified as threatened with extinction (CR: 2; EN: 9; VU: 2) and four species were classified as DD (Suppl. material 1: Table S12).

Legislative inclusion of amphibians from Vietnam

Two genera of amphibians, which are also extant in Vietnam, are listed in CITES Appendix II. Both genera belong to the order Caudata, namely Paramesotriton, represented by two species in Vietnam and Tylototriton, represented by five species, four of which are endemic to Vietnam. Accordingly, only 2.5% of the total species and 4.2% of the endemic species extant in Vietnam are included in CITES. Of the total 49 species evaluated as threatened in Vietnam, only three species are included in Appendix II, namely Paramesotriton guangxiensis (EN), Tylototriton vietnamensis (EN), and Tylototriton ziegleri (VU). On national legislative level, Paramesotriton deloustali and Tylototriton spp. are listed in Group II of Decree No. 06 represented by six species. The List of Threatened Reptiles and Amphibians in the Vietnam Red Data Book lists 12 threatened amphibian species: nine frog species (CR: 1, EN: 6, VU: 2), two salamander species (EN: 2) and one caecilian species (VU: 1). For one species, the conservation status in the Vietnam Red Data Book and on the IUCN Red List is identical while 11 species are classified as more threatened in the Vietnam Red Data Book than on the IUCN Red List. Of the 95 endemic species for Vietnam, two are listed in the Red Data Book, namely Quasipaa delacouri and Tylototriton vietnamensis. Another 25 species have been evaluated as threatened with extinction by the IUCN but are not included in the Vietnam Red List. While the latest version of the Vietnam Red List was published in 2007, 18 of the threatened endemic species were described after 2007 and six frog species were described before that year. An additional species, namely Amolops minutus, was described in the year 2007.

Coverage by protected areas

Of the total 95 endemic species for Vietnam, 82 have been documented within one or more PAs while 13 have been recorded exclusively from locations in unprotected areas (Table 5, Fig. 8). Regarding their IUCN Red List status, two of the 13 amphibian species are classified as threatened (EN: 2), two are classified as DD and no status was available for the remaining nine species.

Figure 8.

Microendemic amphibian species from Vietnam not yet recorded in any protected area. A Limnonectes phuyenensis (Phu Yen) B Amolops ottorum (Son La) C Odorrana mutschmanni (Cao Bang) D Zhangixalus jodiae (Ha Giang) (Photos: C. T. Pham, A. V. Pham and T. T. Nguyen).

Table 5.

Endemic amphibian species from Vietnam not yet recorded in any protected area and the provinces from where the species have been recorded so far. *: species is endemic to this province. Additional information: IUCN Red List status.

Order Species Province(s) IUCN (2021)
Anura Limnonectes phuyenensis Phu Yen *
Leptobrachella kalonensis Binh Thuan *
Leptobrachella macrops Phu Yen, Dak Lak
Leptobrachella pyrrhops Lam Dong *
Leptobrachium xanthospilum Gia Lai * DD
Microhyla aurantiventris Gia Lai *
Nanohyla nanapollexa Quang Nam, Kon Tum DD
Amolops minutus Lai Chau * EN
Amolops ottorum Son La *
Odorrana mutschmanni Cao Bang *
Theloderma ryabovi Kon Tum * EN
Zhangixalus jodiae Ha Giang *
Caudata Tylototriton sparreboomi Lai Chau *
Total 13

An overview of the distributions of local endemic species, species classified as threatened, and endemic species exclusively recorded in unprotected areas in Northern Vietnam is presented in Fig. 9 and for central Vietnam and southeastern Vietnam in Fig. 10. Since there are no species endemic to the Mekong River Delta, no detailed illustration of this region is presented here. Regarding the localities of species recorded exclusively in unprotected areas, Zhangixalus jodiae, Odorrana mutschmanni, Quasipaa acanthophora, and Tylototriton sparreboomi have been found in northern Vietnam partly relatively far away from protected areas and close to the border with China (Fig. 9). Species occurring only in unprotected sites in central Vietnam were all detected in relatively close proximity (<50 km) to protected areas, namely Leptobrachella kalonensis, L. macrops, L. pyrrhops, Leptobrachium xanthospilum, Microhyla aurantiventris, Nanohyla nanapollexa, Theloderma ryabovi, and Limnonectes phuyenensis (Fig. 10).

Figure 9.

Distribution of protected areas in the mainland of northern Vietnam with localities of endemic and threatened endemic species. Green shapes: Protected Areas; Yellow circles: Localities of endemic species; Red triangles: Localities of threatened endemic species.

Figure 10.

Distribution of protected areas in the mainland of central Vietnam with localities of endemic and threatened endemic species. Green shapes: Protected Areas; Yellow circles: Localities of endemic species; Red triangles: Localities of threatened endemic species.

Vietnamese amphibians ex situ

ZIMS

According to ZIMS data, 29 of the total 275 amphibian species reported to occur in Vietnam are represented in global zoos, including four Vietnamese endemic species (Table 6). Thus, 95.8% of the endemic amphibian species from Vietnam are not currently held in zoos (n = 91). Approximately 17% of the species held are classified as threatened by the IUCN, namely Theloderma bicolor, T. ryabovi, Paramesotriton guangxiensis, Tylototriton vietnamensis, and T. ziegleri (5 species; EN: 4; VU: 1), with a further 3% listed as NT (1 species), 76% as LC (22 species) and 3% as NE (1 species). Four threatened species held in ZIMS institutions worldwide account for only 8% of the 50 amphibian species in Vietnam classified as threatened. Of the 29 species kept in total, 13 (45%) were held in only one institution, four species (14%) in two zoos, one species (3%) in three zoos, two species (7%) in four zoos, eight species (26%) in five to 19 zoos and one species (3%), namely Theloderma corticale, in 89 zoos.

Table 6.

Representation of amphibian species reported to occur in Vietnam in ZIMS institutions (n = 25) and ZTL institutions (n = 36). Species: *: species is endemic to Vietnam, **: species is endemic to the Indochinese Region. IUCN status: IUCN Red List status (IUCN 2021), those rated as threatened in bold. Institutions: Number of institutions in number of regions. Individuals: Number of individuals. Hatchings: Offspring in the past 12 months. The following species, Sylvirana cubitalis, S. maosonensis and S. nigrovittata, were listed in ZIMS under the former genus name Hylarana.

Species IUCN status ZIMS ZTL
Institutions (Regions) Individuals Hatchings Institutions
Bombina microdeladigitora VU 3
Bufo gargarizans LC 4 (1) 154 0 2
Duttaphrynus melanostictus LC 19 (3) 1923 103 18
Ingerophrynus galeatus ** LC 5 (1) 93 120 12
Phrynoidis asper LC 14 (3) 61 0 3
Euphlyctis cyanophlyctis LC 1 (1) 3 0
Occidozyga lima LC 3 (1) 12 0 5
Occidozyga martensii LC 1
Hyla chinensis LC 1 (1) 1 0 2
Leptobrachium chapaense LC 1
Glyphoglossus guttulatus LC 1 (1) 10 0 2
Kaloula pulchra LC 18 (5) 64 0 12
Microhyla butleri LC 1 (1) 6 0 1
Microhyla heymonsi LC 1
Microhyla ninhthuanensis* NE 1 (1) 89 88
Microhyla pulchra LC 1 (1) 1 0 1
Hylarana erythraea LC 3
Hylarana taipehensis LC 1
Sylvirana guentheri LC 1
Sylvirana cubitalis LC 7 (1) 291 63 8
Sylvirana maosonensis LC 1 (1) 29 0 1
Sylvirana nigrovittata LC 2 (1) 157 3
Kurixalus bisacculus LC 2 (1) 124 100 4
Kurixalus odontotarsus LC 1 (1) 19 0 2
Nyctixalus pictus NT 10 (2) 128 38 6
Polypedates megacephalus LC 11 (1) 509 57 10
Rhacophorus kio LC 2 (1) 3 0 2
Rhacophorus orlovi ** LC 1 (1) 42 0
Theloderma bicolor EN 9 (1) 118 48 11
Theloderma corticale LC 89 (3) 654 105 69
Theloderma gordoni LC 1 (1) 3 0 2
Theloderma ryabovi * EN 1 (1) 2 0 2
Zhangixalus dennysi LC 20
Zhangixalus duboisi DD 1
Zhangixalus feae LC 7
Paramesotriton deloustali LC 1 (1) 32 0 1
Paramesotriton guangxiensis EN 2 (1) 10 0 2
Tylototriton vietnamensis * EN 4 (1) 154 13 4
Tylototriton ziegleri * VU 1 (1) 69 87 1

Of all amphibian species reported to occur in Vietnam and held in zoos, seven (24%) are represented by fewer than 10 individuals in ZIMS institutions; twelve (41%) with between 10 and 93 individuals; seven (24%) with between 118 and 291 individuals; two (7%) with between 509 and 654 individuals; and one (3%), Duttaphrynus melanostictus, with 1923 individuals. In terms of breeding success, reproduction of 38% of the species held in zoos (11 out of 29 species) were recorded within the last 12 months, including four endemic species from Vietnam and Indochina, namely Ingerophrynus galeatus, Microhyla ninhthuanensis, Tylototriton vietnamensis, and T. ziegleri (examples of threatened species already in ex situ conservation programs are presented in Fig. 11). Considering the distribution of amphibian populations in zoos worldwide, five of the 29 amphibian species known from Vietnam and being held are represented in zoos in Asia, including zoos in Singapore, Dubai, and India, but none in either of the two ZIMS member institutions in Vietnam. All four endemic amphibian species from Vietnam are held exclusively in European zoos.

Figure 11.

Threatened Vietnamese amphibian species already in ex situ conservation breeding programs (Cologne Zoo, Germany). A Ingerophrynus galeatus in amplexus (Vietnam Red Data Book: VU) B Paramesotriton deloustali offspring (CITES: II) C Tylototriton ziegleri (CITES: II, IUCN: VU) D young Tylototriton vietnamensis (CITES: II, IUCN: EN) (Photos: A. Rauhaus and T. Ziegler)

ZTL

ZTL listed 36 species of amphibians reported to occur in Vietnam in European zoos including three Vietnamese endemic species (Table 6). Of all species, 26 are listed in both ZIMS and ZTL, 10 only in the ZTL and three only in ZIMS (Fig. 12). Of the 36 captive held species according to ZTL, six (17%) are classified as threatened by the IUCN, namely Bombina microdeladigitora, Theloderma bicolor, T. ryabovi, Paramesotriton guangxiensis, Tylototriton vietnamensis, and T. ziegleri (EN:4; VU:2), one (3%) as NT, 27 (75%) as LC (n = 27), and each one (3%) as DD and NE. Therefore, only six of the total 49 amphibian species from Vietnam classified as threatened are represented in European zoos according to the ZTL.

Figure 12.

Number of institutions maintaining amphibians reported to occur in Vietnam (after ZIMS and ZTL). Light grey column: Number of institutions after ZIMS; Dark grey column: Number of institutions after ZTL; Striped column: Number of institutions identical after ZIMS and ZTL. *: species is endemic to Vietnam, **: species is endemic to the Indochinese Region.

Diversity analysis

Analyzing the spatial coverage of ZIMS listed zoos keeping amphibian species from Vietnam clearly shows that the highest density is found in Europe and North America (Fig. 13). However, it needs to be noted that this pattern may also reflect the overall higher densities of ZIMS members in these regions.

Figure 13.

Geographic overview of amphibian species reported from Vietnam kept in zoos listed in ZIMS. Countries are shaded according to the number of zoos keeping specimens. Single zoos are highlighted as colored dots referring to the number of individuals per zoo. The size of the dots represents the H = Shannon Weaver Index. North America and Europe are highlighted with the highest density of zoos.

Discussion

Although mostly up to date, the data of this study unlikely reflects the actual species number of Vietnam’s amphibian fauna. Since the cut-off date for our species list (June 2021), another six new species were described from Vietnam and are not included in this study: Gracixalus ziegleri Le, Do, Tran, Nguyen, Orlov, Ninh & Nguyen, 2021, Vietnamophryne cuongi Nguyen, Hoang, Jianping, Orlov, Ninh, Nguyen, Nguyen & Ziegler, 2021, Leptobrachella graminicola Nguyen, Tapley, Nguyen, Luong & Rowley, 2021, Boulenophrys frigida (Tapley, Cutajar, Nguyen, Portway, Mahony, Nguyen, Harding, Luong & Rowley, 2021), Micryletta melanops Poyarkov, Nguyen, Yang & Gorin, 2021, and Theloderma khoii Ninh, Nguyen, Nguyen, Hoang, Siliyavong, Nguyen, Le, Le & Ziegler, 2022. The new species discovery rate of amphibians from Vietnam is still high, as indicated by the 88 newly described species in the last decade, highlighting the outstanding amphibian diversity of the country. In addition, since the publication of the amphibian checklist by Nguyen et al. (2009), a total of 33 new country records have been documented from Vietnam, and there are an additional 12 amphibian species found in localities near the border between neighboring countries and Vietnam that are expected to occur in Vietnam. It is thus certain that additional new species will be described or recorded from Vietnam in the near future. On the other hand, taxonomic revisions, which are warranted for some of the existing taxa, may also alter the number of currently recognized amphibians in the country. For example, based on studies undertaken over the last decade, 20 of the 174 amphibian species listed by Nguyen et al. (2009) have been excluded from Vietnam, while 48 were reassigned to other genera. Moreover, the distribution data presented herein reliably reflect current scientific knowledge, but certainly do not represent the actual distribution of many species, in particular those only recently described and so far, only known from their type localities. Additionally, some of the endemic species occurring close to border areas are expected to be distributed in adjacent countries and therefore not endemic after all, such as Limnonectes nguyenorum McLeod, Kurlbaum & Hoang, 2015 which has recently been reported from China as well (Liu et al. 2022).

Amphibian endemism is not distributed evenly across the landscape of Vietnam with highest numbers of endemic species found in the Central Highlands (26 species endemic to this region), Northeast (14 species), and Northwest (11 species). The data are relatively consistent with the high species richness recorded in the regions. Specifically, the Central Highlands should be prioritized for amphibian conservation as most provincial and local endemic species are located in this region (n = 22) as well as most species classified as threatened by the IUCN Red List (n = 11). More than half of the 95 endemic species (n = 54, 57%) are only known from their type localities, emphasizing the importance of establishing local protected areas and strengthening the already existing protected area network particularly the tropical montane forests in the provinces of Kon Tum, Lam Dong and Lao Cai, for which high numbers of endemic species were recorded.

Only 73.8% of amphibians extant in Vietnam have been assigned an IUCN Red List category and not all the amphibians classified as threatened by the IUCN are protected by national legislations, highlighting the possibility of more far-reaching measures for species protection and conservation. It is noted that Decree No. 64/2019 did not include any amphibian species in the high conservation priority list. Re-evaluation and possible inclusion of endemic and threatened amphibians is highly recommended. More than half of all available threat statuses are outdated and there are differences in quality of the respective reports between previous and more recent reports (IUCN 2021), thus reaffirming the importance of re-evaluations. Further research is especially needed for 33 species classified as DD since DD species are more likely to become extinct than assessed species (Howard and Bickford 2014; Bland et al. 2015). According to the IUCN Standards and Petitions Committee (2019), the species classified as DD should be prioritized by the scientific community to generate data that will allow their proper classification into a threat category. Continued collection of basic biological and ecological information is also particularly relevant for the 51 endemic species that have not yet been evaluated by the IUCN, so that their threat status can be properly assessed.

As only four amphibian species endemic to Vietnam are listed on CITES Appendices, the other 91 endemic species are recommended to be monitored for negative impacts from the trade. In addition, an updated version of the Vietnam Red Data Book is urgently required because conservation statuses of many species from Vietnam have changed substantially since its publication in 2007.

A total of 13 endemic species (14% of all endemics) are recorded exclusively from unprotected areas. Of these species, only Amolops minutus (EN) and Theloderma ryabovi (EN), have been classified by the IUCN as threatened and should be prioritized for further research into their distribution and threats to design appropriate conservation actions, including protected area coverage.

To achieve the goals of the One Plan Approach, the integration of ex situ populations into global species conservation planning and implementation must be strengthened. According to the Convention on Biological Diversity, ex situ efforts are recommended to function as a supporting measure to in situ efforts and ideally enable reintroductions of captive populations into the wild when it is possible. Since the exact origin of most of the kept amphibian populations is not evident in ZIMS, genetic analyses are recommended to determine their provenance or priority should be placed on species or their populations with known geographic origins and endemic species from Vietnam, respectively. As zoos and other husbandry facilities only have limited resources, the selection of species should be well planned and ideally focused on species with a greater need of captive assurance populations and breeding programs. It is also important to further investigate and determine which species would benefit the most from ex situ efforts on a species-by-species basis; as a starting point, range-restricted species could be prioritized. As a specific recommendation resulting from the data compiled herein, a list of top 50 species which might profit most from research and/or conservation efforts was compiled. A ranking scheme was used to generate the list, with points given for 1) Level of endemism, 2) IUCN Red List status, and 3) Not recorded in any protected area. An additional seven species were added because they received the same scores as those ranked from 26 to 50 (Suppl. material 1: Table S13).

Although the data from ZIMS and ZTL are not complete, it is apparent from these zoo databases that only a few amphibian species from Vietnam are present in zoos worldwide. Of the species held in zoos, only a small fraction is kept in more than a hundred individuals each. Overall, a majority of held species are not a priority for conservation (listed as LC) and threatened taxa are underrepresented in zoos. We therefore recommend a general shift from common, non-threatened display species towards establishing ex situ populations of threatened species to address the amphibian crisis. In addition, nearly two-thirds of the held species are only present in one or two institutions. For the maintenance of healthy ex situ populations, a network of keeping facilities is recommended (e.g., Ziegler et al. 2020). It is also important to maintain multiple safeguard populations against unforeseen events (such as disease outbreaks or natural catastrophes) (e.g., Jacken et al. 2020). Only 11 out of 29 held amphibian species exceed the criterion of at least four holding institutions suggested by Jacken et al. (2020). Of the five threatened species (according to IUCN 2021) kept in zoos, only two, Theloderma bicolor and Tylototriton vietnamensis, are currently held in four or more institutions. Of the 13 endemic amphibian species from Vietnam which are recorded exclusively from unprotected areas, only a single species, Theloderma ryabovi (EN), is present in zoos with very few individuals in a single institution according to ZIMS. However, it can be assumed that more amphibian species and a larger number of individuals are kept and bred in captive-breeding centers in the country of origin (Harding et al. 2015) or elsewhere. Local holdings such as in the Me Linh Station for Biodiversity in Vinh Phuc Province, which also include amphibian populations (Ziegler et al. 2016), are not listed in either the ZIMS or the ZTL database. These in country facilities play a special role in developing conservation breeding programs for threatened amphibian species. The map showing the distribution of regional endemic or even micro-endemic amphibians in Vietnam underlines the necessity of scientific institutions and stations in the respective regions to consider conservation of these taxa a top priority, as they are the only ones on site and able to implement effective conservation breeding projects. As an additional measure, co-operation with zoos worldwide is recommended.

Conclusion

Conservation of amphibians in Vietnam could be further improved through continued field research, as well as more targeted support for the highly threatened endemic species analyzed in this study. Monitoring programs are considered especially important for 28 threatened species endemic to Vietnam to assess their population status. Further research is also crucial for the 63 endemic species not yet evaluated by the IUCN or classified as DD and the 13 endemic species exclusively recorded from unprotected areas. Besides threat status assessment, strengthening or establishing new protected areas should be considered, where required. Captive facilities in Vietnam in concert with international zoos should consider shifting their focus towards threatened amphibian species. In particular, regional stations and captive facilities can play a critical role in improving amphibian conservation through making the establishment of husbandry and breeding programs for threatened and microendemic amphibian species a top priority, following the IUCN’s One Plan Approach.

Acknowledgements

We thank Prof. Dr. Lee Grismer (Riverside) and Dr. Arne Schulze (Landau) for kindly reviewing and commenting on a previous version of the manuscript. Many thanks to our colleagues for providing photographs and the map. This research was partially supported by the Vietnam Academy of Science and Technology (Project Code: ĐLSĐ00.01/20-23).

References

  • Adler K (2009) Herpetological exploration, research, and conservation in Vietnam. In: Nguyen SV, Ho CT, Nguyen TQ (Eds) Herpetofauna of Vietnam. Edition Chimaira, Frankfurt am Main, 33–56.
  • AmphibiaWeb (2021) An Online Reference. Electronic Database University of California, Berkeley, Ca, USA. https://amphibiaweb.org [Accessed on 30.06.2021]
  • Baillie JEM, Hilton-Tayler C, Stuart SN [Eds] (2004) 2004 IUCN Red List of Threatened Species: A Global Species Assessment. IUCN, Gland, Switzerland and Cambridge, UK.
  • Bain RH, Hurley MM (2011) A biogeographic synthesis of the amphibians and reptiles of Indochina. Bulletin of the American Museum of Natural History 2011(360): 1–138. https://doi.org/10.1206/360.1
  • Bain RH, Nguyen TQ, Doan KV (2007) New herpetofaunal records from Vietnam. Herpetological Review 38(1): 107–117.
  • Bain RH, Nguyen TQ, Doan KV (2009a) A new species of the genus Theloderma Tschudi, 1838 (Anura: Rhacophoridae) from northwestern Vietnam. Zootaxa 2191: 58–68. https://doi.org/10.5281/zenodo.189385
  • Bain RH, Stuart BL, Nguyen TQ, Che J, Rao DQ (2009b) A new Odorrana (Amphibia: Ranidae) from Vietnam and China. Copeia 2009(2): 348–362. https://doi.org/10.1643/CH-07-195
  • Bernardes M, Le MD, Nguyen TQ, Pham CT, Pham AV, Nguyen TT, Rödder D, Bonkowski M, Ziegler T (2020) Integrative taxonomy reveals three new taxa within the Tylototriton asperrimus complex (Caudata, Salamandridae) from Vietnam. ZooKeys 935: 121–164. https://doi.org/10.3897/zookeys.935.37138
  • Bishop PJ, Angulo A, Lewis JP, Moore RD, Rabb GB, Mainguy JGMG (2012) The Amphibian Extinction Crisis-what will it take to put the action into the Amphibian Conservation Action Plan? SAPI EN. S. Surveys and Perspectives Integrating Environment and Society 5(2): 1–16. http://journals.openedition.org/sapiens/1406
  • Bland LC, Orme CDL, Bielby J, Collen B, Nicholson E, McCarthy MA (2015) Cost-effective assessment of extinction risk with limited information. Journal of Applied Ecology 52(4): 861–870. https://doi.org/10.1111/1365-2664.12459
  • Chan KO, Blackburn DC, Murphy RW, Stuart BL, Emmett DA, Ho CT, Brown RM (2013) A new species of narrow-mouthed frog of the genus Kaloula from eastern Indochina. Herpetologica 69(3): 329–341. https://doi.org/10.1655/HERPETOLOGICA-D-12-00094
  • Chen J, Poyarkov Jr NA, Suwannapoom C, Lathrop A, Wu Y-H, Zhou W-W, Yuan Z-Y, Jin J-Q, Chen H-M, Liu H-Q, Nguyen TQ, Nguyen SN, Duong TV, Eto K, Nishikawa K, Matsui M, Orlov NL, Stuart BL, Brown RM, Rowley JJL, Murphy RW, Wang Y-Y, Che J (2018) Large-scale phylogenetic analyses provide insights into unrecognized diversity and historical biogeography of Asian leaf-litter frogs, genus Leptolalax (Anura: Megophryidae). Molecular Phylogenetics and Evolution 124: 162–171. https://doi.org/10.1016/j.ympev.2018.02.020
  • Clulow J, Trudeau VL, Kouba AJ (2014) Amphibian declines in the twenty-first century: why we need assisted reproductive technologies. In: Holt WV, Brown JL, Comizzoli P (Eds) Reproductive sciences in animal conservation: Progress and Prospects. Springer, New York, 275–316. https://doi.org/10.1007/978-1-4939-0820-2_12
  • Cutajar T, Rowley JJL, Nguyen LT, Nguyen CT, Portway C, Harding L, Luong HV, Tapley B (2020) The advertisement call of Megophrys jingdongensis (Fei and Ye, 1983) and a new record from Lai Chau Province, Northeast Vietnam. Herpetology Notes 13: 139–143.
  • Dubois A, Ohler A (2009) A new species of the genus Quasipaa (Anura, Ranidae, Dicroglossinae) from northern Vietnam. Alytes. Paris 27: 49–61.
  • Duong TV, Do DT, Ngo CD, Nguyen TQ, Poyarkov Jr NA (2018) A new species of the genus Leptolalax (Anura: Megophryidae) from southern Vietnam. Zoological Research/Dōngwùxué yánjiū. Kunming 39: 181–196. https://doi.org/10.24272/j.issn.2095-8137.2018.009
  • Eken G, Bennun L, Brooks TM, Darwall W, Fishpool LDC, Foster M, Knox D, Langhammer P, Matiku P, Radford E, Salaman P, Sechrest W, Smith ML, Spector S, Tordoff A (2004) Key Biodiversity Areas as Site Conservation Targets. Bioscience 54(12): 1110–1118. https://doi.org/10.1641/0006-3568(2004)054[1110:KBAASC]2.0.CO;2
  • Frost DR (2021) Amphibian Species of the World: An Online Reference. Version 6. American Museum of Natural History, New York, USA. Electronic Database accessible at https://amphibiansoftheworld.amnh.org/index.php [Accessed on 30.06.2021]
  • Gascon C, Collins JP, Moore RD, Church DR, McKay JE, Mendelson Jr III (2007) Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group. Gland, Switzerland and Cambridge, UK, 64 pp.
  • Gawor A, Pham CT, Nguyen TQ, Nguyen TT, Schmitz A, Ziegler T (2016) The herpetofauna of the Bai Tu Long National Park, northeastern Vietnam. Salamandra (Frankfurt) 52: 23–41.
  • Geissler P, Poyarkov Jr NA, Grismer LL, Nguyen TQ, An HT, Neang T, Kupfer A, Ziegler T, Böhme W, Müller H (2015) New Ichthyophis species from Indochina (Gymnophiona, Ichthyophiidae): 1. The unstriped forms with descriptions of three new species and the redescriptions of I. acuminatus Taylor, 1960, I. youngorum Taylor, 1960 and I. laosensis Taylor, 1969. Organisms, Diversity & Evolution 15(1): 143–174. https://doi.org/10.1007/s13127-014-0190-6
  • Gorin VA, Scherz MD, Korost DV, Poyarkov Jr NA (2021) Consequences of parallel miniaturisation in Microhylinae (Anura, Microhylidae), with the description of a new genus of diminutive South East Asian frogs. Zoosystematics and Evolution 97(1): 21–54. https://doi.org/10.3897/zse.97.57968
  • Graf R, Pfleiderer J, Fritsche M, Schmidt J, Mantei R, Peter S, Spangenberg F (2021) Zootierliste [ZTL]. http://www.zootierliste.de/ [Accessed 21.10.2020]
  • Harding G, Griffiths RA, Pavajeau L (2015) Developments in amphibian captive breeding and reintroduction programs. Conservation Biology 30(2): 340–349. https://doi.org/10.1111/cobi.12612
  • Hendrix R, Nguyen TQ, Böhme W, Ziegler T (2008) New anuran records from Phong Nha–Ke Bang National Park, Truong Son, central Vietnam. Herpetology Notes 1: 23–31.
  • Hoang CV, Nguyen TT, Ninh HT, Luong AM, Pham CT, Nguyen TQ, Orlov NL, Chen Y, Wang B, Ziegler T, Jiang J (2021) Two new cryptic species of Microhyla Tschudi, 1838 (Amphibia, Anura, Microhylidae) related to the M. heymonsi group from central Vietnam. ZooKeys 1036: 47–74. https://doi.org/10.3897/zookeys.1036.56919
  • Howard SD, Bickford DP (2014) Amphibians over the edge: Silent extinction risk of Data Deficient species. Diversity & Distributions 20(7): 837–846. https://doi.org/10.1111/ddi.12218
  • Hussain QA, Pandit AK (2012) Global amphibian declines: A review. International Journal of Biodeversity and Conservation 4(10): 348–357. https://doi.org/10.5897/IJBC12.008
  • Jacken A, Rödder D, Ziegler T (2020) Amphibians in zoos: A global approach on distribution patterns of threatened amphibians in zoological collections. International Zoo Yearbook 54(1): 146–164. https://doi.org/10.1111/izy.12272
  • Kilpatrick AM, Briggs CJ, Daszak P (2010) The ecology and impact of chytridiomycosis: An emerging disease of amphibians. Trends in Ecology & Evolution 25(2): 109–118. https://doi.org/10.1016/j.tree.2009.07.011
  • Kropachev II, Orlov NL, Ninh HT, Nguyen TT (2019) A new species of Rhacophorus genus (Amphibia: Anura: Rhacophoridae: Rhacophorinae) from Van Ban District, Lao Cai Province, northern Vietnam. Russian Journal of Herpetology 26(6): 325–334. https://doi.org/10.30906/1026-2296-2019-26-6-325-334
  • Le DT, Do YT (2019) Limnonectes nguyenorum McLeod, Kurlbaum & Hoang 2015 (Anura: Dicroglossidae), a new frog record from Yen Bai Province, northwestern Vietnam. Hnue Journal of Science. Natural Sciences. Hanoi 64: 141–147. https://doi.org/10.18173/2354-1059.2019-83
  • Le DT, Pham AV, Nguyen SLH, Ziegler T, Nguyen TQ (2014) Babina lini (Chou, 1999) and Hylarana menglaensis Fei, Ye et Xie, 2008, two additional anuran species for the herpetofauna of Vietnam. Russian Journal of Herpetology 21(4): 315–321. www.rjh.folium.ru/index.php/rjh/article/view/911
  • Le DT, Pham AV, Nguyen SLH, Ziegler T, Nguyen TQ (2015a) First records of Megophrys daweimontis Rao and Yang, 1997 and Amolops vitreus (Bain, Stuart and Orlov, 2006) (Anura: Megophryidae, Ranidae) from Vietnam. Asian Herpetological Research 6: 66–72. https://doi.org/10.16373/j.cnki.ahr.140045
  • Le DT, Nguyen TT, Nishikawa K, Nguyen SLH, Pham AV, Matsui M, Bernardes M, Nguyen TQ (2015b) A new species of Tylototriton Anderson, 1871 (Amphibia: Salamandridae) from northern Indochina. Current Herpetology. Kyoto 34(1): 38–50. https://doi.org/10.5358/hsj.34.38
  • Liu S, Mo M, Rao D (2022) First country record of the fanged frog Limnonectes nguyenorum McLeod, Kurlbaum & Hoang, 2015 (Anura, Dicroglossidae) in China. Herpetozoa (Wien) 35: 1–7. https://doi.org/10.3897/herpetozoa.35.e78015
  • Luong AM, Nguyen HQ, Le DT, Nguyen SLH, Nguyen TQ (2019) New records of amphibians (Anura: Megophryidae, Ranidae) from Dien Bien Province, Vietnam. Herpetology Notes 12: 375–387.
  • Luong AM, Pham CT, Do QH, Hoang CV, Phan TQ, Nguyen TQ, Ziegler T, Le MD (2021) New records and an updated checklist of amphibians from Lai Chau Province, Vietnam. Check List 17(2): 445–458. https://doi.org/10.15560/17.2.445
  • Luu VQ, Nguyen TQ, Pham CT, Dang KN, Vu TN, Miskovic S, Bonkowski M, Ziegler T (2013) No end in sight? Further new records of amphibians and reptiles from Phong Nha-Ke Bang National Park, Quang Binh Province, Vietnam. Biodiversity Journal 4: 285–300.
  • Martel A, Spitzen-van der Sluijs A, Blooi M, Bert W, Ducatelle R, Fisher MC, Woeltjes A, Bosman W, Chiers K, Bossuyt F, Pasmans F (2013) Batrachochytrium salamandrivorans sp. nov. causes lethal chytridiomycosis in amphibians. Proceedings of the National Academy of Sciences of the United States of America 110(38): 15325–15329. https://doi.org/10.1073/pnas.1307356110
  • Matsui M, Hamidy A, Murphy RW, Khonsue W, Yambun P, Shimada T, Ahmad N, Belabut DM, Jiang JP (2010) Phylogenetic relationships of megophryid frogs of the genus Leptobrachium (Amphibia, Anura) as revealed by mtDNA gene sequences. Molecular Phylogenetics and Evolution 56(1): 259–272. https://doi.org/10.1016/j.ympev.2010.03.014
  • McLeod DS, Kurlbaum S, Hoang NV (2015) More of the same: a diminutive new species of the Limnonectes kuhlii complex from northern Vietnam (Anura: Dicroglossidae). Zootaxa 3947(2): 201–214. https://doi.org/10.11646/zootaxa.3947.2.4
  • Meiri S, Bauer AM, Allison A, Castro-Herrera F, Chirio L, Colli G, Das I, Doan TM, Glaw F, Grismer LL, Hoogmoed M, Kraus F, LeBreton M, Meirte D, Nagy ZT, Nogueira CC, Oliver P, Pauwels OSG, Pincheira-Donoso D, Shea G, Sindaco R, Tallowin OJS, Torres-Carvajal O, Trape JF, Uetz P, Wagner P, Wang Y, Ziegler T, Roll U (2017) Extinct, obscure or imaginary: The lizard species with the smallest ranges. Diversity & Distributions 24(2): 262–273. https://doi.org/10.1111/ddi.12678
  • Melville J, Chapple DG, Keogh JS, Summer J, Amey A, Bowles P, Brennan IG, Couper P, Donnellan SC, Doughty P, Edwars DL, Ellis RJ, Esquerré D, Fenker J, Gardner MG, Georges A, Haines ML, Hoskin CJ, Hutchinson M, Moritz C, Nankivell J, Oliver P, Pavón-Vázquez CJ, Pepper M, Rabosky DL, Sanders K, Shea G, Singhal S, Wilmer JW, Tingley R (2021) A return-on-investment approach for prioritization of rigorous taxonomic research needed to inform responses to the biodiversity crisis. PLOS Biology 19(6): e300121. https://doi.org/10.1371/journal.pbio.3001210
  • Mittermeier RA, Myers N, Thomsen JB, da Fonseca GAB, Olivieri S (1998) Biodiversity Hotspots and Major Tropical Wilderness Areas: Approaches to Setting Conservation Priorities. Conservation Biology 12(3): 516–520. https://doi.org/10.1046/j.1523-1739.1998.012003516.x
  • Mittermeier RA, Turner WR, Larsen FW, Brooks TM, Gascon C (2011) Global Biodiversity Conservation: The Critical Role of Hotspots. In: Zachos F, Habel J (Eds) Biodiversity Hotspots. Springer, Berlin, 3–22. https://doi.org/10.1007/978-3-642-20992-5_1
  • Morice A (1875) Coup d’oeil sur la faune de la Cochinchine française, par M. le Dr Albert Morice (H. Georg).
  • Myers N, Mittermeier RA, Mittermeier CG, da Fonseca GAB, Kent J (2000) Biodiversity hotspots for conservation priorities. Nature 403(6772): 853–858. https://doi.org/10.1038/35002501
  • Nguyen LT, Poyarkov NA Jr, Le DT, Vo BD, Ninh HT, Duong TV, Murphy RW, Sang NV (2018b) A new species of Leptolalax (Anura: Megophryidae) from Son Tra Peninsula, central Vietnam. Zootaxa 4388(1): 1–21. https://doi.org/10.11646/zootaxa.4388.1.1
  • Nguyen LT, Tapley B, Nguyen CT, Luong HV, Rowley JJL (2021b) A new species of Leptobrachella (Anura, Megophryidae) from Mount Pu Ta Leng, northwest Vietnam. Zootoxa 5016(3): 301–332. https://doi.org/10.11646/zootaxa.5016.3.1
  • Nguyen SV, Ho CT, Nguyen TQ (2005) Danh Luc Ech Nhai Va Bo Sat Viet Nam/A Checklist of the Amphibians and Reptiles of Vietnam. Hanoi: Nha Xuat Ban Hong Nghiep.
  • Nguyen SV, Ho CT, Nguyen TQ (2009) : Herpetofauna of Vietnam. Ed. Chimaria.
  • Nguyen TT, Tran TT, Nguyen TQ, Pham CT (2008) Geographic distribution: Rhacophorus maximus. Herpetological Review 39: 364.
  • Nguyen TT, Le DT, Nguyen SLH, Matsui M, Nguyen TQ (2014a) First record of Philautus petilus Stuart and Heatwole, 2004 (Amphibia: Anura: Rhacophoridae) from Vietnam and its phylogenetic position. Current Herpetology. Kyoto 33(2): 112–120. https://doi.org/10.5358/hsj.33.112
  • Nguyen TT, Matsui M, Duc HM (2014b) A new tree frog of the genus Kurixalus (Anura: Rhacophoridae) from Vietnam. Current Herpetology. Kyoto 33(2): 101–111. https://doi.org/10.5358/hsj.33.101
  • Nguyen TT, Ninh HT, Orlov NL, Nguyen TQ, Ziegler T (2020a) A new species of the genus Zhangixalus (Amphibia: Rhacophoridae) from Vietnam. Journal of Natural History 54(1-4): 257–273. https://doi.org/10.1080/00222933.2020.1754484
  • Nguyen TQ (2006) Herpetological collaboration in Vietnam. In: Vences M, Köhler J, Ziegler T, Böhme W (Eds) Herpetologia Bonnensis II. Proceedings of the 13th Congress of the Societas Europaea Herpetologica, 233–240.
  • Nguyen TQ, Le MD, Pham CT, Nguyen TT, Bonkowski M, Ziegler T (2013) A new species of Gracixalus (Amphibia: Anura: Rhacophoridae) from northern Vietnam. Organisms, Diversity & Evolution 13(2): 203–214. https://doi.org/10.1007/s13127-012-0116-0
  • Nguyen TV, Pham CT, Do DT, Ziegler T, Nguyen TQ (2018a) New records and first description of females of the large-eared frog, Odorrana gigatympana (Orlov, Ananjeva et Ho, 2006) (Anura: Ranidae), from Vietnam. Russian Journal of Herpetology 25(3): 239–244. https://doi.org/10.30906/1026-2296-2018-25-3-239-244
  • Nguyen TV, Hoang CV, Jianping J, Orlov NL, Ninh HT, Nguyen HQ, Nguyen TT, Ziegler T (2021a) A new species of Vietnamophryne with an extended description of Vietnamophryne orlovi. Russian Journal of Herpetology 28(6): 355–368. https://doi.org/10.30906/1026-2296-2021-28-6-355-368
  • Ninh HT, Nguyen TT, Orlov NL, Nguyen TQ, Ziegler T (2020) A new species of the genus Zhangixalus (Amphibia: Rhacophoridae) from Vietnam. European Journal of Taxonomy 688(688): 1–8. https://doi.org/10.5852/ejt.2020.688
  • Ninh HT, Nguyen TT, Nguyen HQ, Hoang NV, Siliyavong S, Nguyen TV, Le DT, Le QK, Ziegler T (2022) A new species of mossy frog (Anura: Rhacophoridae) from Northeastern Vietnam. European Journal of Taxonomy 794: 72–90. https://doi.org/10.5852/ejt.2022.794.1655
  • Nishikawa K, Matsui M, Nguyen TT (2013) A new species of Tylototriton from northern Vietnam (Amphibia: Urodela: Salamandridae). Current Herpetology (Kyoto) 32(1): 34–49. https://doi.org/10.5358/hsj.32.34
  • Noss RF, Platt WJ, Sorrie BA, Weakley AS, Means DB, Costanza J, Peet RK (2015) How global biodiversity hotspots may go unrecognized: Lessons from the North American Coastal Plain. Diversity & Distributions 21(2): 236–244. https://doi.org/10.1111/ddi.12278
  • Ohler A, Marquis O, Swan SR, Grosjean S (2000) Amphibian biodiversity of Hoang Lien Nature Reserve (Lao Cai Province, northern Vietnam) with description of two new species. Herpetozoa (Wien) 13: 71–87. https://www.zobodat.at/pdf/HER_13_1_2_0071-0087.pdf
  • Ohler A, Wollenberg KC, Grosjean S, Hendrix R, Vences M, Ziegler T, Dubois A (2011) Sorting out Lalos: Description of new species and additional taxonomic data on megophryid frogs from northern Indochina (genus Leptolalax, Megophryidae, Anura). Zootaxa 3147(1): 1–83. https://doi.org/10.11646/zootaxa.3147.1.1
  • Oksanen J, Guillaume Blanchet F, Friendly M, Kindt R, Legendre P, McGlinn D, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Szoecs E, Wagner H (2020) vegan: Community Ecology Package. R package version 2.5–7. https://CRAN.R-project.org/package=vegan
  • Ong AV, Hoang TN, Hoang QX, Nguyen TT, Ho TA (2020) Survey Results on amphibians and reptiles in Nam Dan District, Nghe An Province, Vietnam. Studia Universitatis Moldaviae 1(131): 135–139. https://doi.org/10.5281/zenodo.3954013
  • Orlov NL (2008) Description of a new species of Rhacophorus genus (Amphibia: Anura: Rhacophoridae) from Kon Cha Rang area (Gia Lai Province, Vietnam). Russian Journal of Herpetology 15(2): 133–140. rjh.folium.ru/index.php/rjh/article/view/173
  • Orlov NL, Poyarkov Jr NA, Vassilieva AB, Ananjeva NB, Nguyen TT, Sang NV, Geissler P (2012) Taxonomic notes on rhacophorid frogs (Rhacophorinae: Rhacophoridae: Anura) of southern part of Annamite Mountains (Truong Son, Vietnam), with description of three new species. Russian Journal of Herpetology 19(1): 23–64. rjh.folium.ru/index.php/rjh/article/view/457
  • Orlov NL, Dutta SK, Ghate HV, Kent Y (2006) New species of Theloderma from Kon Tum Province (Vietnam) and Nagaland State (India) (Anura: Rhacophoridae). Russian Journal of Herpetology 13(2): 135–154. www.rjh.folium.ru/index.php/rjh/article/view/805
  • Pabijan M, Palomar G, Antunes B, Antol W, Zielinski P, Babik W (2020) Evolutionary principles guiding amphibian conservation. Evolutionary Applications 13(5): 857–878. https://doi.org/10.1111/eva.12940
  • Pham AV, Nguyen TQ (2018a) Thành phần thức ăn của loài Ếch gai Vân Nam Nanorana yunnanensis (Anderson, 1879) ở tỉnh Sơn La. VNU Journal of Science: Natural Sciences and Technology 34: 10–16. http://repository.vnu.edu.vn/handle/VNU_123/62800
  • Pham AV, Le DT, Nguyen SLH, Ziegler T, Nguyen TQ (2014) First records of Leptolalax eos Ohler, Wollenberg, Grosjean, Hendrix, Vences, Zeigler et Dubois, 2011, and Hylarana cubitalis (Smith, 1917) (Anura: Megophryidae, Ranidae) from Vietnam. Russian Journal of Herpetology 21(3): 195–200. www.rjh.folium.ru/index.php/rjh/article/view/862
  • Pham AV, Le DT, Pham CT, Nguyen SLH, Ziegler T, Nguyen TQ (2016b) Two additional records of megophryid frogs, Leptobrachium masatakasatoi Matsui, 2013 and Leptolalax minimus (Taylor, 1962), for the herpetofauna of Vietnam. Revue Suisse de Zoologie 123: 35–43. https://doi.org/10.5281/zenodo.46287
  • Pham AV, Hoang TLQ, Pham CT, Nguyen TQ (2019a) Diversity of the Family Rhacophoridae (Amphibia: Anura) in Lai Chau Province, Vietnam. VNU Journal of Science: Natural Sciences and Technology 35: 2. https://doi.org/10.25073/2588-1140/vnunst.4880
  • Pham AV, Pham CT, Doan LD, Ziegler T, Nguyen TQ (2019b) New records of megophryids (Amphibia: Anura: Megophryidae) from Son La Province, Vietnam. Biodiversity Data Journal 7(e39140): 1–18. https://doi.org/10.3897/BDJ.7.e39140
  • Pham AV, Sung NB, Pham CT, Le MD, Ziegler T, Nguyen TQ (2019c) A new species of Amolops (Anura: Ranidae) from Vietnam. Raffles Bulletin of Zoology. Singapore 67: 363–377. https://doi.org/10.26107/RBZ-2019-0027
  • Pham CT, Nguyen TQ, Bernardes M, Nguyen TT, Ziegler T (2016a) First records of Bufo gargarizans Cantor, 1842 and Odorrana lipuensis Mo, Chen, Wu, Zhang et Zhou, 2015 (Anura: Bufonidae) from Vietnam. Russian Journal of Herpetology 23(2): 103–107. www.rjh.folium.ru/index.php/rjh/article/view/1040
  • Pham CT, Le MD, Nguyen TT, Ziegler T, Wu ZJ, Nguyen TQ (2017c) A new species of Limnonectes (Amphibia: Anura: Dicroglossidae) from Vietnam. Zootaxa 4269(4): 545–558. https://doi.org/10.11646/zootaxa.4269.4.8
  • Pham CT, Rauhaus A, Tran TD, Niggemann C, Dang PH, Le MD, Nguyen TQ, Ziegler T (2019d) First record of Gracixalus quangi Rowley, Dau, Nguyen, Cao & Nguyen, 2011, from Hoa Binh Province, Vietnam, including the first documentation of advanced larval stages and an extended tadpole description. Amphibian & Reptile Conservation 13: 90–103. amphibian-reptile-conservation.org/archive.html
  • Pham CT, Le MD, Hoang CV, Pham AV, Ziegler T, Nguyen TQ (2020a) First records of Bufo luchunnicus (Yang et Rao, 2008) and Amolops wenshanensis Yuan, Jin, Li, Stuart et Wu, 2018 (Anura: Bufonidae, Ranidae) from Vietnam. Russian Journal of Herpetology 27(2): 81–86. https://doi.org/10.30906/1026-2296-2020-27-2-81-86
  • Pham CT, Do DT, Le MD, Ngo HT, Nguyen LT, Ziegler T, Nguyen TQ (2020c) A new species of Limnonectes (Amphibia: Anura: Dicroglossidae) from Vietnam. Zootaxa 4894(3): 387–402. https://doi.org/10.11646/zootaxa.4894.3.5
  • Pham CT, Do QH, Ngo HN, Tran TT, Ziegler T, Nguyen TQ (2020d) First report on the anuran fauna of Hai Ha forest, Quang Ninh Province, Vietnam. Check List. The Journal of Biodiversity Data 16: 1025–1041. https://doi.org/10.15560/16.4.1025
  • Poyarkov Jr NA, Duong TV, Orlov NL, Gogoleva SI, Vassilieva AB, Nguyen LT, Nguyen VDH, Nguyen SN, Che J, Mahony S (2017) Molecular, morphological and acoustic assessment of the genus Ophryophryne (Anura, Megophryidae) from Langbian Plateau, southern Vietnam, with description of a new species. ZooKeys 672: 49–120. https://doi.org/10.3897/zookeys.672.10624
  • Poyarkov Jr NA, Suwannapoom C, Pawangkhanant P, Aksornneam A, Duong TV, Korost DV, Che J (2018a) A new genus and three new species of miniaturized microhylid frogs from Indochina (Amphibia: Anura: Microhylidae: Asterophryinae). Zoological Research/Dōngwùxué yánjiū (Kunming) 38(3): 1–26. https://doi.org/10.24272/j.issn.2095-8137.2018.019
  • Poyarkov Jr NA, Nguyen TV, Duong TV, Gorin VA, Yang JH (2018b) A new limestone-dwelling species of Micryletta (Amphibia: Anura: Microhylidae) from northern Vietnam. PeerJ 6(e5771): 1–27. https://doi.org/10.7717/peerj.5771
  • Poyarkov Jr NA, Kropachev II, Gogoleva SI, Orlov NL (2018c) A new species of the genus Theloderma Tschudi, 1838 (Amphibia: Anura: Rhacophoridae) from Tay Nguyen Plateau, central Vietnam. Zoological Research/Dōngwùxué yánjiū (Kunming) 39: 156–180. https://doi.org/10.24272/j.issn.2095-8137.2018.018
  • Poyarkov Jr NA, Nguyen TV, Arkhipov DV (2021a) A new species of the genus Tylototriton (Amphibia, Caudata, Salamandridae) from central Vietnam. Taprobanica. The Journal of Asian Biodiversity 10: 4–22. https://doi.org/10.47605/tapro.v10i1.244
  • Poyarkov Jr NA, Nguyen TV, Yang Jh, Gorin VA (2021b) : A new species of Micryletta (Amphibia: Anura: Microhylidae) from the Langbian Plateau in southern Vietnam. Zoological Research/Dōngwùxué yánjiū (Kunming) 42: 726–733 https://doi.org/10.24272/j.issn.2095-8137.2021.228
  • Purvis A, Gittleman JL, Cowlishaw G, Mace GM (2000) Predicting extinction risk in declining species. Proceedings of the Royal Society of London. Series B, Biological Sciences 267(1456): 1947–1952. https://doi.org/10.1098/rspb.2000.1234
  • QGIS Development Team (2021) QGIS Geographic Information System (QGIS Association) http://www.qgis.org [Accessed on 30.06.2021]
  • Rowley JJL, Tran DTA, Hoang HD, Le DTT (2012b) A new large species of large Flying Frog (Rhacophoridae: Rhacophorus) from lowland forests of southern Vietnam. Journal of Herpetology 46(4): 480–487. https://doi.org/10.1670/11-261
  • Rowley JJL, Le DTT, Dau QV, Hoang HD, Cao T (2014) A striking new species of phytotelm-breeding tree frog (Anura: Rhacophoridae) from central Vietnam. Zootaxa 3785(1): 25–37. https://doi.org/10.11646/zootaxa.3785.1.2
  • Rowley JJL, Stuart BL, Neang T, Hoang HD, Dau QV, Nguyen TT, Emmett DA (2015) A new species of Leptolalax (Anura: Megophryidae) from Vietnam and Cambodia. Zootaxa 4039(3): 401–417. https://doi.org/10.11646/zootaxa.4039.3.1
  • Rowley JJL, Tran DTA, Le DTT, Dau QV, Peloso PLV, Nguyen TQ, Hoang HD, Nguyen TT, Ziegler T (2016) Five new, microendemic Asian Leaf-litter Frogs (Leptolalax) from the southern Annamite mountains, Vietnam. Zootaxa 4085(1): 63–102. https://doi.org/10.11646/zootaxa.4085.1.3
  • Rowley JJL, Dau VQ, Hoang HD, Le DTT, Cutjara TP, Nguyen TT (2017) A new species of Leptolalax (Anura: Megophryidae) from northern Vietnam. Zootaxa 4243(3): 544–564. https://doi.org/10.11646/zootaxa.4243.3.7
  • Rowley JJL, Le DTT, Hoang HD, Cao TT, Dau QV (2020) A new species of phytotelm breeding frog (Anura: Rhacophoridae) from the Central Highlands of Vietnam. Zootaxa 4779: 341–354. https://doi.org/10.11646/zootaxa.4779.3.3
  • Schloegel LM, Hero JM, Berger L, Speare R, McDonald K, Daszak P (2006) The Decline of Sharp-Snouted Day Frog (Taudactylus acutirostris): The First Documented Case of Extinction by Infection in a Free-Ranging Wildlife Species. EcoHealth 3(1): 35–40. https://doi.org/10.1007/s10393-005-0012-6
  • Semlitsch RD (2003) Amphibian Conservation. Smithsonian Institution, Washington.
  • Sheridan JA, Stuart BL (2018) Hidden species diversity in Sylvirana nigrovittata (Amphibia: Ranidae) highlights the importance of taxonomic revisions in biodiversity conservation. PLoS ONE 13(3): e0192766. https://doi.org/10.1371/journal.pone.0192766
  • Sterling EJ, Hurley MM, Le MD (2006) Vietnam: A Natural History. Yale University Press.
  • Stork NE, Habel JC (2014) Can biodiversity hotspots protect more than tropical forest plants and vertebrates? Journal of Biology 41: 421–428. https://doi.org/10.1111/jbi.12223
  • Stuart BL, Bain RH, Phimmachak S, Spence K (2010) Phylogenetic Systematics of the Amolops monticola Group (Amphibia: Ranidae), with Description of a New Species from Northwestern Laos. Herpetologica 66(1): 52–66. https://doi.org/10.1655/08-073.1
  • Stuart BL, Rowley JJL, Tran DTA, Le DTT, Hoang HD (2011) The Leptobrachium (Anura: Megophryidae) of the Langbian Plateau, southern Vietnam, with description of a new species. Zootaxa 2804(1): 25–40. https://doi.org/10.11646/zootaxa.2804.1.3
  • Tapley B, Cutajar T, Mahony S, Nguyen CT, Dau VQ, Luong AM, Le DT, Nguyen TT, Nguyen TQ, Portway C, Luong HV, Rowley JJL (2018) Two new and potentially highly threatened Megophrys Horned frogs (Amphibia: Megophryidae) from Indochina’s highest mountains. Zootaxa 4508(3): 301–333. https://doi.org/10.11646/zootaxa.4508.3.1
  • Tapley B, Cutajar TP, Nguyen LT, Portway C, Mahony S, Nguyen CT, Harding L, Luong HV, Rowley JJL (2021) A new potentially Endangered species of Megophrys (Amphibia: Megophryidae) from Mount Ky Quan San, north-west Vietnam. Journal of Natural History 54(39–40): 2543–2575. https://doi.org/10.1080/00222933.2020.1856952
  • Tran DTA, Le QK, Le KV, Vu TN, Nguyen TQ, Böhme W, Ziegler T (2010) First and preliminary frog records (Amphibia: Anura) from Quang Ngai Province, Vietnam. Herpetology Notes 3: 111–119.
  • Tran K, Ho CT, Nguyen SV, Pham T (2007) List of Threatened Reptiles and Amphibians. In: Dang NT, Tran K, Dang HH, Nguyen C, Nguyen N, Nguyen YH, Dang D (Eds) Vietnam Red Data Book. Part I. Animals, 114–118.
  • Tran TT, Le DT (2021) The first list of amphibians and reptiles from Soc Son Watershed Protection Forest, Ha Noi City, Vietnam. Academia Journal of Biology 43(1): 61–76. https://doi.org/10.15625/2615-9023/14450
  • Vassilieva AB, Galoyan EA, Gogoleva SI, Poyarkov Jr NA (2014) Two new species of Kalophrynus Tschudi, 1838 (Anura: Microhylidae) from the Annamite mountains in southern Vietnam. Zootaxa 3796(3): 401–434. https://doi.org/10.11646/zootaxa.3796.3.1
  • Vredenburg VT, Knapp RA, Tunstall TS, Briggs CJ (2010) Dynamics of an emerging disease drive large-scale amphibian population extinctions. Proceedings of the National Academy of Sciences of the United States of America 107(21): 9689–9694. https://doi.org/10.1073/pnas.0914111107
  • Wake DB, Vredenburg VT (2008) Are we in the midst of the sixth mass extinction? A view from the world of amphibians. Proceedings of the National Academy of Sciences of the United States of America 105(supplement_1): 11466–11473. https://doi.org/10.1073/pnas.0801921105
  • Whiles MR, Lips KR, Pringle CM, Kilham SS, Bixby RJ, Brenes R, Connelly S, Colon-Gaud JC, Hunte-Brown M, Huryn AD, Montgomery C, Peterson C (2006) The effects of amphibian population declines on the structure and function of Neotropical stream ecosystems. Frontiers in Ecology and the Environment 4(1): 27–34. https://doi.org/10.1890/1540-9295(2006)004[0027:TEOAPD]2.0.CO;2
  • Wu YH, Yan F, Stuart BL, Prendini E, Suwannapoom C, Dahn HA, Zhang BL, Cai H-X, Xu Y-B, Jiang K, Chen H-M, Lemmon AR, Lemmon EM, Raxworthy CJ, Orlov NL, Murphy RW, Che J (2020) A combined approach of mitochondrial DNA and anchored nuclear phylogenomics sheds light on unrecognized diversity, phylogeny, and historical biogeography of the torrent frogs, genus Amolops (Anura: Ranidae). Molecular Phylogenetics and Evolution 144(106701): 1–13. https://doi.org/10.1016/j.ympev.2020.106789
  • Yu Gh, Rao Dq, Matsui M, Yang Jx (2017) Coalescent-based delimitation outperforms distance-based methods for delineating less divergent species: the case of Kurixalus odontotarsus species group. Scientific Reports (Nature, London) 7(16124): 1–13. https://doi.org/10.1038/s41598-017-16309-1
  • Yu G, Hui H, Hou M, Wu Z, Rao D, Yang J (2019b) A new species of Zhangixalus (Anura: Rhacophoridae), previously confused with Zhangixalus smaragdinus (Blyth, 1852). Zootaxa 4711(2): 275–292. https://doi.org/10.11646/zootaxa.4711.2.3
  • Zheng Y, Zhang S, Lu Q, Zhang S, Wang L, Hong M, Nguyen TQ, Zhao J, Yao M (2021) Population genetic patterns of mangrove associated frog reveal its colonization history and habitat connectivity. Diversity & Distributions 0(8): 1–17. https://doi.org/10.1111/ddi.13304
  • Ziegler T, Nguyen TQ (2019) Herpetological research and conservation in Vietnam and Laos in compliance with the one plan approach. Proc. 4th Nat Sci Conf Amph Rept Vietnam.
  • Ziegler T, Rauhaus A, Mutschmann F, Dang PH, Pham CT, Nguyen TQ (2016) Building up of keeping facilities and breeding projects for frogs, newts and lizards at the Me Linh Station for Biodiversity in northern Vietnam, including improvement of housing conditions for confiscated reptiles and primates. Der Zoologische Garten 85(3–4): 91–120. https://doi.org/10.1016/j.zoolgart.2015.09.001
  • Ziegler T, Rauhaus A, Niggemann C, Nicolaudius J, Bernardes M, Nguyen TQ (2020, December) Developing a conservation breeding network for threatened Vietnamese Crocodile Newts. AArk Newsletter (52): 9–12.
  • Ziegler T, Tran DTA, Nguyen TQ, Perl RGB, Wirk L, Kulisch M, Lehmann T, Rauhaus A, Nguyen TT, Le QK, Vu TN (2014) New amphibian and reptile records from Ha Giang Province, northern Vietnam. Herpetology Notes 7: 185–201.
  • Zippel K, Johnson K, Gagliardo R, Gibson R, McFadden M, Browne R, Martinez C, Townsend E (2011) The Amphibian Ark: A Global Community for Ex situ Conservation of Amphibians. Herpetological Conservation and Biology 6(3): 340–352.

Supplementary material

Supplementary material 1 

Assessment of the threat status of the amphibians in Vietnam - Implementation of the One Plan Approach

Marie Krzikowski, Truong Quang Nguyen, Cuong The Pham, Dennis Rödder, Anna Rauhaus, Minh Duc Le, Thomas Ziegler

Data type: Original data

Explanation note: Species list, endemic species, new records, distribution, top 57 list.

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
Download file (103.45 kb)