Biotic Survey Focal Taxa

Research into Vietnam's natural history has had a long albeit sporadic history dating back to the turn of the 20th century. From the late 1800s through the 1930s, historical Indochina (Vietnam, Cambodia, Lao PDR and southern China) was the focus of exploration and natural history collections by primarily French and North American researchers, including Bourret, Coolidge, Delacour and Osgood. Following the Second World War, conflicts and political isolation limited biodiversity research until Russian researchers began working in concert with the Vietnamese in the 1970s following reunification. Recently this region has experienced an explosion of biotic inventory activity, resulting in many new taxa descriptions and geographic range extensions as well as exploration of the factors underlying species diversity and distribution patterns.

Renewed interest in Vietnamese biodiversity can be partly attributed to the fact that, despite this extensive historical activity, a number of geographic regions and important floral and faunal groups remain virtually unknown. Previous work has concentrated on generally well-known groups (birds, large mammals) and inventories of organisms such as vascular plants and freshwater fishes frequently consist of unverified checklists based on site observations. Comprehensive surveys of other taxa, including well-characterized ones, under-represent large sections of the country, e.g. the extensive area east of the Red River in northern Vietnam.

The joint CBC-AMNH/IEBR/MBG research expedition surveyed six focal taxa in three regions of Vietnam: amphibians and reptiles, birds, freshwater fishes, invertebrates, mammals and vascular plants (flora). These taxa and focal groups within them were selected because they met one or more of the following key criteria:

  • Scientists at the American Museum of Natural History, Missouri Botanical Gardens, and the Institute for Ecology and Biological Resources are specialists in the groups;
  • Additional collections will contribute to phylogenetic studies and knowledge of biogeography, species richness, and distributions;
  • Combined they can provide a cross-section of overall diversity for assessing the richness and conservation status of a region; and
  • Collecting techniques suitable for comparative analyses are available for each group.

A brief summary of historical survey work, current knowledge and focal groups for each of the following taxa are provided below.

Amphibians & Reptiles
Large scale survey work on Vietnamese herpetofauna essentially ceased between 1945 and the 1990s and, with a few exceptions, regional monographs on Indochinese amphibians and reptiles pre-date the Second World War. The species diversity and conservation status of amphibian and reptile taxa in this region are interesting for a variety of reasons. First, recent survey work in Vietnam indicates potentially high levels of hidden biodiversity in anuran species complexes (e.g., ranids, rachophorids). Assessing amphibian species richness and endemism requires taxonomic revisions based on both on-going surveys and existing natural history collections. Second, snakes and especially turtles are under intensive harvesting pressure to supply local and regional markets, creating an urgent need for information on the diversity, ecology, taxonomy and conservation status of these taxa.

The avifauna of Vietnam and the surrounding regions has been the focus of exciting and productive scientific investigations for more than eight decades. The French ornithologist and natural historian Jean Delacour undertook seven major research expeditions to Indochina between 1923 and 1939, five of which visited present-day Vietnam. More recent activity has identified three new montane passerine taxa from the Kon Tum Plateau and four Endemic Bird Areas are now recognized in Vietnam. Despite the intensity of previous work we included birds in the focal taxa because the fauna is well-described, they are generally diurnal, obvious and easily surveyed, and new taxa and range extensions are still being uncovered. Their distributions are also likely to help clarify how the intergradation of sub-tropical and tropical biota across latitudinal and altitudinal gradients structures observed biodiversity patterns.

Freshwater Fishes
Freshwater ichthyofauna is under-surveyed and under-described throughout Indochina. Current checklists of fishes from Northern and Southern Vietnam are believed to represent approximately 80% of actual diversity, and of these roughly 50% of taxa descriptions consist of single known localities and associated habitats. Fauna inhabiting streams draining the eastern slopes of the Annamite Cordillera to the Gulf of Tonkin are particularly poorly known, although there is evidence of distinct biogeographic affinities north (to taxa found in the Red River Delta and South China) and south (to taxa in the Mekong Delta) of the Hai Van Pass, c. 16° N. Results from these surveys will produce a number of new species descriptions, help clarify existing nomenclature, and contribute to surveying and monitoring protocols.

Invertebrates are the most diverse group of animals on earth and can provide an enormously rich data set for analyzing patterns of species richness, distribution and diversity across a variety of gradients. They can also be readily collected using standard protocols, allowing for robust comparative analyses between research sites. The following taxa within invertebrates were selected to provide a cross-section of arthropod diversity and because they met the other focal taxa requirements:
Arachnida: Ctenidae (wandering spiders)
Heteroptera: Reduviidae (ambush or assassin bugs)
Coleoptera: Staphylinidae (rove beetles)
Hymenoptera: social Vespidae (wasps) and Braconidae (parasitoid wasps)
Diptera: Mycetophilidae (fungus gnats) and Drosophilidae (fruit flies)

Large mammals are the most intensively and extensively surveyed group in Vietnam and the fauna contains a number of important taxa, including four endemic, globally threatened primate species and three recently described artiodactyles. To complement this work, the CBC-AMNH/IEBR surveys chose to focus on small mammals, bats and insectivores. Apart from Osgood's 1932 survey of Indochinese mammals, research into the diversity and distribution of these taxa has been limited and there are few modern survey protocols and identification guides available. Small mammal surveys can potentially provide both baseline and monitoring data on species richness and distribution and information on overall ecosystem health using standardized collection methods. This approach is especially useful in countries such as Vietnam where moderate habitat disturbance and intense human exploitation of the large mammal fauna can make conservation assessments challenging.

Vietnam's floristic diversity is high given the country's size. Approximately 12,000 vascular plant species are predicted to occur in the country, fewer than 8,000 of which have been identified; 10% of these species and 3% of the genera are believed to be endemic. Diversity patterns across latitudinal and altitudinal gradients are often complex, reflecting the admixture of sub-tropical and tropical biota and Vietnam's complex geology, topography and climate. Research scientists from the MBG and IEBR will identify all flowering plants, ferns and mosses collected to family; they expect that 10-20% of these collections will be previously undescribed.


Arthropod Biotic Surveys

Estimates of global insect species diversity vary greatly, running from a low of 1.84 million to more than 50 million total species. In large part this uncertainty reflects our poor knowledge of the ecological and evolutionary processes structuring speciation and the maintenance of diversity in these groups. Current consensus figures lie between 4 and 10 million species, approximately 1 million of which have been described to date. Compiling accurate lists of currently known taxa and estimating true invertebrate diversity totals for individual countries is difficult. A review of zoological literature from 1990 to the present provides an indication of Vietnam's hidden arthropod biodiversity as well as the active state of research: examining only those articles describing generic and higher level taxa, we found 318 new species descriptions, 90% of which are restricted to the country.

In addition to uncovering novelty, a survey of arthropods can be a useful tool in biodiversity and conservation research. The high diversity of anthropods and our ability to sample large numbers of taxa and individuals using standardized protocols makes this an excellent research group for a variety of comparative analyses. These include examinations of local community structure, species distribution across elevational, climatic and latitudinal gradients, and biogeographical hypotheses of species diversity patterns. Results from this research can address basic ecological and evolutionary questions and also inform conservation and protected area management plans.

The Center for Biodiversity and Conservation at the American Museum of Natural History in New York and the Institute for Ecology and Biological Resources in Hanoi jointly surveyed arthropod biodiversity in three regions of Vietnam, 1998-2000. This research was intended to estimate overall species richness and faunal turnover along altitudinal gradients and to measure the diversity and distribution of organisms and identify new taxa in the focal groups. Methods were designed to allow comparative analyses between sites and to assess the conservation and biodiversity value of these currently unprotected areas.


Reduviidae (Heteroptera: Cimicomorpha) collected in the Northern Truong Son Mountains (1998) and Ngoc Linh Mountain Range (1999) of Vietnam. The subfamilies pictured are (from left): Harpactorinae, Stenopodainae, Ectrichodiinae.

Brian Trotta


Herpetology Biotic Surveys

Current estimates of herpetofauna diversity in Vietnam name approximately 100 amphibian and 180 reptile species, a relatively high proportion of which (20 to 25%, est.) are either endemic to Vietnam or occupy restricted ranges in the region. One amphibian (the endemic Vietnamese Salamander, Paramesotriton deloustali) and 27 reptile species (primarily turtles) are listed as Vulnerable, Endangered or Critically Endangered by the IUCN (2000).

The Center for Biodiversity and Conservation (AMNH) and the Institute for Ecology and Biological Resources in Hanoi surveyed amphibian and reptile biodiversity at three sites in Vietnam, 1998-2000. In addition, a brief pilot study was carried out in 1997. The research was designed to assess the degree and distribution of species diversity, identify new taxa and range extensions, and assess the conservation importance of these currently unprotected areas.


Dorsal (left) and ventral (right) views of Bombina microdeladigitora, the Yunnan Firebelly Toad.

Raoul Bain


Ichthyology Biotic Surveys

Tropical Asia and Southeast Asia host a rich freshwater fish fauna numbering over 3,000 species in 121 families (including 18 regional endemics). Despite this high recorded biodiversity, Southeast Asia in general and Vietnam in particular remain both under-surveyed and under-described. This is especially true of the river basins draining the eastern slopes of the Truong Son Mountains along the Vietnam-Lao PDR border. Roughly 450 fish species are currently known from the inland waters of Vietnam, a list which constitutes (at best) 80% coverage of extant freshwater ichthyofauna biodiversity. The need for further exploration and conservation assessments coincides with expanding threats to freshwater resources from flow alteration and water diversion, increased sediment load, introduced species, overfishing and habitat loss. Currently seven species of freshwater fish occurring in Vietnam have been placed on the IUCN Red List (2000), including Mekong Freshwater Stingray Dasyatis laosensis, the regionally endemic Giant Mekong Catfish Pangasianodon gigas, and Asian Arowana Scleropages formosus, restricted in Vietnam to the east slopes of the Truong Son Mountains. This is clearly an incomplete assessment of Vietnam's threatened freshwater fish species.

The Center for Biodiversity and Conservation at the American Museum of Natural History in New York and the Institute for Ecology and Biological Resources in Hanoi, jointly surveyed freshwater ichthyofauna at three locations in Vietnam, 1998-2000. Research was designed to record the diversity and distribution of freshwater fish species, identify new taxa, record range extensions, provide baseline data for monitoring freshwater ecosystem health, and assess the conservation and biodiversity value of currently unprotected areas.


River loach, cf. Homalosoma (Balitoridae) collected in Ha Giang.


Mammalogy Biotic Surveys

A diverse assemblage of over 200 mammals inhabits Vietnam, reflecting the intergradation of Sino-Himalayan and Indo-Malayan biogeographic zones and the presence of a regionally endemic fauna centered on the Truong Son Mountains. It includes five recently discovered or re-discovered mammals with distributions limited to a subset of Indochina (including Vietnam): Heude's Pig Sus bucculentus, Large-antlered Muntjac Muntiacus vuquangensis, Annamite Muntjac M. truongsonensis, Roosevelts' Muntjac M. rooseveltorum and Annamite Striped Rabbit Nesolagus timminsi. This burst of research into Vietnam's complex species diversity has coincided with increasing threats to its conservation. Thirty-seven mammal species - over 17% of the total - are currently listed as Globally Threatened by the IUCN (2000). These threatened taxa include four species on Conservation International's list of the twenty-five most endangered primates in the world: Delacour's Langur Trachypithecus delacouri, Cat Ba Golden-headed Langur T. poliocephalus, Gray-shanked Douc Langur Pygathrix nemaeus cinerea and Tonkin Snub-nosed Monkey Rhinopithecus avunculus. Exploitation, habitat loss and human activity also threaten the less visible small mammal species critical to overall ecosystem health.

The Center for Biodiversity and Conservation at the American Museum of Natural History in New York and the Institute for Ecology and Biological Resources in Hanoi jointly surveyed small and large mammals in the Northern Truong Son Mountains in 1998 and 1999. Research was designed to assess species richness and distribution, record threatened species, identify new taxa and range extensions, provide baseline data for monitoring ecosystem health, and assess the conservation and biodiversity value of this currently unprotected area.

Complementing the field research, Darrin Lunde from AMNH and Nguyen Truong Son from IEBR collaborated on the fully-illustrated "Identification Guide to the Rodents of Vietnam" (2001). The guide includes a taxonomic key to Families and diagnosis of Subfamilies in the Order Rodentia, species range maps, natural history notes, and information on preparation, curation and collections management techniques. 

Lunde, D.P., and Nguyen Truong Son. 2001. "An Identification Guide to the Rodents of Vietnam." Center for Biodiversity and Conservation at the American Museum of Natural History, New York, NY.



Melogale moschata, the Small-toothed Ferret Badger (Mustelidae). From Rao An, Huong Son District, Ha Tinh Province.


Ornithology Biotic Surveys

Current estimates place the number of bird species present in Vietnam at nearly 850. Sixty-three of these - over 7% - are classified as either Globally Threatened or Near Threatened. In the last five years, three new montane passerine species have been described from the Central (or Western) Highlands of Vietnam: Golden-winged Laughingthrush Garrulax ngoclinhensis, Black-crowned Barwing Actinodura sodangorum, and Chestnut-eared Laughingthrush G. konkakinhensis. These novel species and the identification of a number of new subspecies and range extensions from throughout the country suggest that the extent and distribution of Vietnam's avifauna requires further study.

The Center for Biodiversity and Conservation at the American Museum of Natural History in New York and the Institute for Ecology and Biological Resources in Hanoi jointly surveyed avifauna at three research sites in Vietnam during 1999 and 2000. Research was designed to assess species richness and the distribution of biodiversity, note the presence of threatened species, identify new taxa and range extensions, and assess the conservation and biodiversity value of these currently unprotected areas.


Cissa hypoleuca, the Indochinese Green Magpie, from Ngoc Linh (Quang Nam Province). Endemic east of the Mekong River in Vietnam, Lao PDR, Cambodia, and south China.

Judith Eger


For annual summaries of survey methods, results and links to species inventories, please visit the following pages:

For a list of published and in preparation identifications, revisions and range extensions based on these survey results, please visit Publications.