Taxonomy Ecology And Conservation Of Snakes Serpentes In Border Areas Between Laos And Son La Province

MINISTRY OF EDUCATION

AND TRAINING

MINISTRY OF AGRICULTURE

AND RURAL DEVELOPMENT

VIETNAM NATIONAL UNIVERSITY OF FORESTRY

DINH SY TUONG

TAXONOMY, ECOLOGY AND CONSERVATION OF SNAKES

(SERPENTES) IN BORDER AREAS BETWEEN LAOS

AND SON LA PROVINCE

MAJOR: FOREST SCIENCE

CODE: 8620201

MASTER THESIS IN FOREST SCIENCE

ACADEMIC ADVISOR:

ASSOC. PROF. DR LUU QUANG VINH

HaNoi, October 2022

i

ABSTRACT

This research was conducted to provide the information of snake

species in three communes that border with Laos. Twenty-five species of

snakes have been recorded within surveys from May 17th

- May 28th 2022,

June 10th

- June 22nd 2022 and June 25th

- July 2nd 2022 in Tan Xuan, Chieng

Khua and Chieng Tuong communes. The number of snake species in these

three communes has increased to 42. Remarkably, there are 9 new recorded of

species was described (Dendrelaphis, Gonyosoma, Lycodon, Oligodon,

Hebius, Pareas, Trimeresurus) for Van Ho District and 3 new recorded for

Moc Chau District (Rhabdophis, Protobothrops, Parafimbrios). The main

threats to the snake fauna are created by human activities. Therefore, the

research has recommended some solutions for reducing the threats consisting

of managing, keeping and protecting snakes in these three communes.

ii

TABLE OF CONTENTS

ABSTRACT...................................................................................................... i

TABLE OF CONTENTS................................................................................ii

ABBERVIATIONS ........................................................................................ iv

LIST OF TABLES .......................................................................................... v

LIST OF FIGURES ....................................................................................... vi

CHAPTER 1: INTRODUCTION.................................................................. 1

CHAPTER 2: LITERATURE REVIEW...................................................... 4

2.1. Snake fauna diversity in Southeast Asia ............................................... 4

2.2. Snake fauna research in Vietnam.......................................................... 4

2.3. Snake fauna research in Laos................................................................ 8

2.4. Snake diversity in border areas with Laos of Son La Province .......... 10

CHAPTER 3: GOAL, OBJECTIVES, AND RESEARCH QUESTIONS11

3.1 Goal ...................................................................................................... 11

3.2 Specific Objectives............................................................................... 11

3.3 Research Questions.............................................................................. 11

CHAPTER IV: STUDY AREA ................................................................... 12

4.1. Location............................................................................................... 12

4.2. Climate ................................................................................................ 13

4.3. Forestry resources ............................................................................... 14

CHAPTER V: METHODS .......................................................................... 18

5.1 Field surveys and data collection ......................................................... 18

5.2 Distribution characteristic of snakes.................................................... 31

5.3. Comparisons of the species similarity composition between border

areas............................................................................................................ 32

5.4. Evaluating conservation status of snake species................................. 32

5.5. Conservation issues............................................................................. 33

iii

CHAPTER VI: RESULTS ........................................................................... 34

6.1. Snake species composition in the study sites...................................... 34

6.1.1. List of snakes from these three communes................................... 34

6.1.2. New records of snakes in the study sites ...................................... 40

6.1.3. Description of non-new recorded snake species in Tan Xuan,

Chieng Khua and Chieng Tuong communes.......................................... 56

6.2. Distribution of snake species across habitat types and elevations in the

study site..................................................................................................... 67

6.2.1. Distribution by elevations............................................................. 67

6.2.2. Distribution by habitats................................................................. 70

6.2.3. Distribution by microhabitats ....................................................... 71

6.3. Conservation issues............................................................................. 72

6.3.1. Conservation status....................................................................... 72

6.3.2. Threat to snake fauna in the study site.......................................... 75

6.4. Solutions for conservation and management of snake fauna in the

study site..................................................................................................... 79

CHAPTER VII: DISCUSSIONS ................................................................. 81

7.1. Ecological characteristics of snake fauna in the study area ................ 81

7.2. Comparisons of the species similarity composition between border

areas............................................................................................................ 82

7.3. The snake community of Son La compared to that of Houaphan....... 84

CHAPTER VIII: CONCLUSION............................................................... 87

ACKNOWLEDGEMENTS.......................................................................... 89

THREE OF ARTICLES RELATED WITH THIS THESIS.................... 90

REFERENCES.............................................................................................. 91

iv

ABBERVIATIONS

a.s.l Above sea level

CR Critically Endangered

EN Endangered

NT Near Threatened

IUCN International Union for Conservation of Nature

RBVN Vietnam Red Data Book

VU Vulnerable

v

LIST OF TABLES

Table 5.1. List of survey transects, survey time and participants................... 20

Table 5.2. Field survey note............................................................................ 27

Table 5.3. Field survey sheet........................................................................... 28

Table 5.4. Abbreviations of main morphological characteristics................... 28

Table 5.5. Abbreviations of scales in snake group ......................................... 29

Table 5.6. Distribution of snakes along elevation gradients........................... 31

Table 5.7. Macrohabitat selection by snakes in these three communes ......... 32

Table 5.8. Microhabitat selection by snakes in these three communes.......... 32

Table 5.9. List of threatened species............................................................... 33

Table 6.1. List of recorded snakes from three communes.............................. 35

Table 6.2. List of threatened species............................................................... 73

Table 7.1. Ecological characteristics of snake fauna by humidity, temperature

and collected time............................................................................................ 81

Table 7.2. Similarity index (Sorensen-Dice index) on snake species

composition between Son La Province and some neighboring province which

also border with Laos...................................................................................... 83

vi

LIST OF FIGURES

Figure 2.1. Diversity of snakes in Southeast Asia countries during 2010 –

2022 (Source: Uetz et al. 2022) 4

Figure 2.2. Number of snake species descriptions increases over 12 years in

Vietnam (Source: Uetz et al. 2022)................................................................... 5

Figure 4.1. Study site map............................................................................... 16

Figure 4.2. Topography map of these three communes that border with Laos17

Figure 5.1. Map of transects survey in Tan Xuan commune .......................... 18

Figure 5.2. Map of survey transects in Chieng Khua commune..................... 19

Figure 5.3. Map of transects survey in Chieng Tuong commune................... 19

Figure 5.4. Location of funnel trap in the study area...................................... 21

Figure 5.5. Material for trap making (Design by Russell Gray)..................... 22

Figure 5.6. Funnel and trap body (Design by Russell Gray) .......................... 23

Figure 5.7. Connecting the two heads of the funnel and the trap compartment

(Design by Russell Gray)................................................................................ 24

Figure 5.8. Fixing and completing the funnel trap (Design by Russell Gray).... 25

Figure 5.9. Diagram of funnel trap system (Design by Russell Gray) ........... 26

Figure 5.10. Scale in head pattern of snake (Manthey & Grossmann, 1997)..... 30

Figure 5.11. Body scale count (Manthey & Grossmann, 1997) ..................... 30

Figure 5.12: Ventral, subcudal and cloacal scale (Manthey & Grossmann,

1997)................................................................................................................ 30

Figure 6.1. Snake diversity in three communes border with Laos by family

and genera ....................................................................................................... 39

Figure 6.2. Snake species from this study in comparison with previous

document …………………………………………………………………. 40

Figure 6.3. (A) Dorsal and (B) ventral views of Dendrelaphis ngansonensis

(TX2.22.44). Photos by Tuong. S. Dinh ......................................................... 41

vii

Figure 6.4. (A) Dorsal and (B) ventral views of Dendrelaphis pictus

(TX2.22.06). Photos by Tuong. S. Dinh ......................................................... 42

Figure 6.5. (A) Dorsal and (B) ventral views of Gonyosoma boulengeri

(TX2.22.36). Photos by Tuong. S. Dinh ......................................................... 43

Figure 6.6. (A) Dorsal and (B) ventral views of Lycodon fasciatus

(TX.22.05). Photos by Tuong. S. Dinh ........................................................... 45

Figure 6.7. (A) Dorsal and (B) ventral views of Oligodon chinensis

(TX2.22.40). Photos by Tuong. S. Dinh ......................................................... 46

Figure 6.8. (A) Dorsal and (B) ventral views of Hebius chapaensis

(TX2.22.30). Photos by Tuong. S. Dinh ......................................................... 47

Figure 6.9. (A) Dorsal and (B) ventral views of Pareas carinatus

(TX2.22.42). Photos by Tuong. S. Dinh ......................................................... 48

Figure 6.10. (A) Dorsal and (B) ventral views of Pareas hamptoni

(TX2.22.41). Photos by Tuong. S. Dinh ......................................................... 49

Family Viperidae Oppel, 1811........................................................................ 49

Figure 6.11. (A) Dorsal and (B) ventral views of Trimeresurus cf. guoi

(TX2.22.39). Photos by Tuong. S. Dinh ......................................................... 51

Figure 6.12. (A) Dorsal and (B) ventral views of Rhabdophis helleri

(CK2.22.40). Photos by Thinh. L. Nghiem..................................................... 53

Family Viperidae Oppel, 1811........................................................................ 53

Figure 6.13. (A) Dorsal and (B) ventral views of Protobothrops

mucrosquamatus (CK.22.37). Photos by Thinh. L. Nghiem.......................... 54

Family Xenodermatidae Gray, 1849............................................................... 54

Figure 6.14. Dorsal view of Parafimbrios cf. lao (CK2.22.18). Photos by

Vinh. Q. Luu.................................................................................................... 56

Figure 6.15. (A) Dorsal and (B) ventral views of Ahaetulla prasina

(CK.22.08). Photos by Duc. T. Ha.................................................................. 58

viii

Figure 6.16. (A) Dorsal and (B) ventral views of Calamaria pavimentata

(TX2.22.03). Photos by Tuong. S. Dinh ......................................................... 59

Figure 6.17. (A) Dorsal and (B) ventral views of Lycodon futsingensis

(TX2.22.17). Photos by Tuong. S. Dinh ......................................................... 60

Figure 6.18. (A) Dorsal and (B) ventral views of Oreocryptophis

porphyraceus (TX2.22.43). Photos by Tuong. S. Dinh.................................. 61

Figure 6.19. (A) Dorsal and (B) ventral views of Ptyas korros (TX.22.01).

Photos by Duc. T. Ha ...................................................................................... 63

Family Natricidae Bonaparte, 1838 ................................................................ 63

Figure 6.20. (A) Dorsal and (B) ventral views of Fowlea flavipunctatus

(CK.22.06). Photos by Tuong. S. Dinh........................................................... 64

Figure 6.21. (A) Dorsal and (B) ventral views of Trimerodytes percarinatus

(TX2.22.15). Photos by Phuong. V. Nguyen.................................................. 66

Family Viperidae Oppel, 1811........................................................................ 66

Figure 6.22. (A) Dorsal and (B) ventral views of Protobothrops

mucrosquamatus (TX2.22.14). Photos by Tuong. S. Dinh............................. 67

Figure 6.23: Number of species distribution by elevation ranges .................. 69

Figure 6.24: Number of family and species distribution by elevation ranges69

Figure 6.25: Number of family and species distribution by habitats.............. 71

Figure 6.26. Graph show the number of species distribution in microhabitats72

Figure 6.27. Milpa in Tan Xuan Commune .................................................... 75

Photo by Vinh. Q. Luu .................................................................................... 75

Figure 6.28. Milpa in Chieng Khua Commune............................................... 76

Photo by Tuong. S. Dinh................................................................................. 76

Figure 6.29. One adult Dendrelaphis pictus dead on road by road kill. Photo

by Vinh. Q. Luu............................................................................................... 77

Figure 6.30. One adult male Trimeresurus cf. guoi dead on the mipla by

human kill in Tan Xuan commnune. Photo by Tuong. S. Dinh ..................... 77

ix

Figure 6.31. One adult Dendrelaphis pictus dead on road by human kill.

Photo by Vinh. Q. Luu .................................................................................... 78

Figure 6.32. One adult Elaphe taeniura dead on the road by human kill in

Chieng Khua commnune. Photo by Thinh. L. Nghiem .................................. 78

Figure 7.1. Analysis of groupings of similarity in species composition

between Son La Province and some neighboring province which also border

with Laos (bootstrap replicates 1000 times) ................................................... 83

1

CHAPTER 1: INTRODUCTION

Currently, there are about 4000 species of snakes belonging to 520

genera and 20 families distributed in the world except Antarctica, and on most

smaller land masses (Uetz et al. 2022). Despite their unwarranted reputation,

snakes are critically important animals for our world. Snakes maintain

balance in the food web and therefore keep ecosystems healthy. They provide

humans an ecological service by controlling pest populations. Snakes are truly

interesting and amazing animals, which are celebrated or worshiped in

cultures around the globe. Yet, due to increased conflict with humans, several

snake species are under threat of extinction. According to (Bohm et al. 2013),

the percentage of threatened snake species worldwide is 11.7%. There are

many threats to snakes including habitat loss, road kill, human kill and

poachers (Santos et al. 2008; Datta et al. 2018).

Vietnam is home for more than 200 snakes, particularly in the tropical

forest habitats (Uetz et al. 2022). In Vietnam, snakes distribute from the north

to the south region. The threats of snakes in Vietnam, same as in many other

countries across the continent, include habitat loss, hunting, poaching, snake

wine (Somaweera & Somaweera 2010; Vassilieva et al. 2016).

Vietnam and Laos share a border with a total length of more than 2,000

km (Sterling et al. 2006). The area with limestone mountain ecosystems

adjacent to Laos is mainly concentrated in some provinces including: Dien

Bien, Son La, Thanh Hoa, Nghe An, Ha Tinh, Quang Binh and Thua Thien￾Hue (Do 2001; Sterling et al. 2006, Grismer et al. 2021). This limestone

mountain ecosystem has an altitude from 0 to more than 2,000 m above sea

level and has a diverse structure such as terrestrial islands, mountain ranges,

caves, etc. biological and highly endemic. Furthermore, structures like natural

2

islands, providing distinct micro-habitats, will play an important role in the

evolution of species (Sterling et al. 2006, Grismer et al. 2021). However, this

mountain ecosystem is very sensitive to human impact and once affected, it is

very difficult to restore. Limestone ranges in Vietnam have been exploited

and unsustainably used for infrastructure development and tourism (Luu &

Lo, 2018).

Son La Province is located in the Northwest region of Vietnam

bordering with Laos (Houaphanh province). In 2009, Nguyen et al. recorded

42 snake species for Son La province. In the following years Pham et al.

(2013 and 2014) recorded 11 more species. In 2015, there were two species

recorded for the first time in Vietnam: Trimerodytes yunnanensis by Le et al.

and Parafimbrios lao by Teynié et al. at Sop Cop and Copia Nature Reserve.

By 2019, also in the Copia Nature Reserve, a new species Achalinus timi by

Ziegler et al. for science was described. In 2019, Luu et al. published a new

record of Ptyas nigromarginata for Son La. In 2020, Pham et al. published 5

more new record species of snakes. In 2021, Dinh et al. published a new

record of Naja kaouthia for this province. Currently, there is one new species

Achalinus vanhoensis have been published in Van Ho district by Ha et al.

(2022), combination with the previous data to bringing the total number of

snakes to the whole Son La province to 64 species.

Tan Xuan, Chieng Tuong and Chieng Khua are three communes of Son

La Province that border with Laos, there is not many specific investigations,

studies and reports on fauna from these communes, in Tan Xuan commune

already have 2 previous research from Nguyen et al. (2009) and Nguyen et al.

(2010) have been published 32 species in Xuan Nha commune and Xuan Nha

Nature Reserve. Currently the information on vertebrates in these three

3

communes is almost unknown, especially about snakes are a group of little

concern such as: species diversity, conservation status and habitat.

Therefore, I will conduct research on the topic: "Taxonomy, Ecology

and Conservation of snakes (Serpentes) in border area between Laos and

Son La Province". The main purpose of this study is to explore the diversity,

ecology and conservation of snakes in the area mentioned above.

4

CHAPTER 2: LITERATURE REVIEW

2.1. Snake fauna diversity in Southeast Asia

The number of snake species have slightly increased in some of

Southeast Asia countries from 2010 up to now, including: Timor Leste

increased only 1 species bring the number of snakes from 14 to 15 species,

Myanmar, Malaysia, Laos, Philippines and Cambodia increased by 12, 10, 8,

6 and 5 species, respectively with total being 223 (Malaysia), 191 (Myanmar),

147 (Philippines), 113 (Laos) and 102 (Cambodia). Thailand and Indonesia

have increased 20 species a total of 238 and 371 respectively. Vietnam have

the highest increases of snakes in Southeast Asia with 37 species and total

262. In two other countries, Singapore and Brunei there were no new species

descriptions for snakes (Uetz et al. 2022).

Figure 2.1. Diversity of snakes in Southeast Asia countries during 2010 –

2022 (Source: Uetz et al. 2022)

2.2. Snake fauna research in Vietnam

In 2022, the total number of snake species in Vietnam is 262 (Uetz et

al. 2022). Snakes are widely distributed in many areas of Vietnam including

plains, midland, mountainous, nature forest, stream and river. The number of

snake species has increased rapidly when new species have been described