Some Ecological Aspects of White-lipped Pit Viper, Trimeresurus albolabris Gray 1842 in Yangon University Campus Ko Myint 1 and Khin Mi Mi Zaw 2

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1 Universities Research Journal 2011, Vol. 4, No. 2 Some Ecological Aspects of White-lipped Pit Viper, Trimeresurus albolabris Gray 1842 in Yangon University Campus Ko Myint 1 and Khin Mi Mi Zaw 2 Abstract The snake species, Trimeresurus albolabris was recorded in the campus of Yangon University which situated at the elevation of 18 m to 26 m above sea level. The present study was carried out during March 2009 to February The observation was based on the data about six individuals for vertical distribution and four for feeding/hunting. This species preferred inhabiting shrubs to other kind of plants. They were mostly active in late hot season and rainy season. The frogs and lizards were observed as their main food sources. Key words: seasonal occurrence, habitat preference, feeding, vertical distribution Introduction The snake species, Trimeresurus albolabris is a venomous viper species belonging to Family Viperidae found in Southeast Asia: India (Assam), Thailand, Cambodia, Laos, Vietnam, China, Malaysia, western Indonesia and Myanmar (Smith, 1943). In Myanmar eight viperid snake species (Leviton et al., 2003) under genus Trimeresurus are currently recognized: Trimeresurus albolabris; T. erythrurus; T. medoensis; T. popeiorum; T. purpureomaculatus; T. stejnegeri; T. yunnanensis and T. albolabris. Two subspecies have been described: T. a. insularis from eastern Indonesia and T. a. septentrionalis from Nepal and northwestern India (Siam-Info, 2011). The snake is nocturnal and in search for food (rodents, frogs, lizards, birds). They also move on the ground at night. It is often found in heavily degraded forest, or in agricultural areas. It was documented to occur in moist mixed deciduous and subtropical forests (both Northern Triangle and Northern Indochina) as well as temperate forests (Cox, 1991). High elevation range is a limiting factor for distribution, in Myanmar they were recorded at elevations range from m (Leviton et al., 2003). It prefers lowland habitats, both forested and open field (Baker, 2011). The biology of white-lipped pit viper snake from southern India, Indochina, Thailand and Myanmar up to now is poorly 1, 2. Assistant Lecturers, Department of Zoology, Hinthada University

2 256 Universities Research Journal 2011, Vol. 4, No. 2 studied. The problems are the complicated identification of species and entangled history of synonyms and taxonomy of this group (Siam-Info, 2011). The aim of the study was to present about this species, Trimeresurus albolabris existing large number in Yangon University campus. Study Area University of Yangon is situated at (16 46 N, 96 º 08 E), elevation of 18m to 26m above sea level, hectares wide on the corner of Pyay Road and University Avenue Road of Kamayut Township. Forest type in the campus was mixed deciduous as described by Department of Geography with different species of tall trees, shrubs, and grass lands. After Nargis Cyclone which hit on 2 May, 2008 to lower part of Myanmar, about 900 tall and aged trees were fallen and uprooted. After that the forest of big and tall tree dominate environment was changed to medium size plant and shrub dominated environment. Kamayut Township obtained average annual rainfall in ( mm), temperature 33.1 C (91.58 F) and relative humidity 75%. Study Period and Methods This study was carried out in the campus of University of Yangon during March 2009 to February The identification of plants was made according to Hundley and Chit Ko Ko (1961). For the identification of study snake (based on five individuals), it was followed after Smith (1943), O'Shea & Halliday (2002) and Leviton et al. (2003). For the examining of diet components, observation was based on four individuals of study species. For seasonal distribution, the numbers of study species encountered at the same day or night were recorded. The strata of distribution of the study snake was based on six individuals. The seasonal distribution of this snake species on habitats associated with the kind of plants and bushes (bamboo, small tree, shrub, climber and herb) were differentiated. According to Baker (2011), their distribution patterns designed on strata of plants and shrubs (top of the plant or shrub, mid of the plant or shrub and at the base of the plant or shrub) with the time influence. The time period with vertical distributions on different strata of the shrubs were divided into three: the first interval from 17:00 to 19:00 hr, the second from 19 to 23 hr and for the third interval time, from 21to 23 hr. There were 2 hours taken at each interval. The air temperature and relative humidity were recorded by using thermohygrometer.

3 Universities Research Journal 2011, Vol. 4, No Results The white-lipped pit viper, Trimeresurus albolabris (Fig. 1), was found to be inhabiting throughout the different habitats of University s Campus in all three seasons. Fig. 1 White-lipped pit viper, Trimeresurus albolabris Seasonal occurrence This species was recorded throughout the year in the campus of Yangon University. Their population of this snake was observed in hot and rainy seasons than cold season during the study period (Table 1). Distributional preference The occurrence of observed frequency number of the species in the different habitats was recorded (Table 1). That was also presented associated with their habitats (Fig. 2) and vertical distribution in different strata: top of the shrub, mid of shrub and at the base shrub (Table 2). Their distribution patterns varied at the different temperature and humidity were recorded. This species was observed throughout the year in the campus during the study period. During the hot season and early rainy season, they were abundant among the shrubs and recorded as their most active time. At that time the temperature was (max 38.4 C, min 25.5 C) and the relative humidity (max 96%, min 33%) in hot season while the temperature (max 34 C, min 23 C) and the relative humidity (max 100%, min 65%) in rainy season. They were rarely found in cold season with the temperature (max 35.2 C, min 19.3 C) and the relative humidity (max 96%, min 37%). During the late hot season and early rainy season, they were commonly encountered at the base of bamboo stands (Dendrocalamus brandisii). At night in these seasons they

4 258 Universities Research Journal 2011, Vol. 4, No. 2 were found the among branches of the shrubs on the distance of 15-45cm above the ground while at day time were from cm above the ground among the thick leafy shrubs. During cold season and early hot season, they were observed commonly in the branches of the trees (Tamarindus indica, Mesua ferrea, Amherstiga nobilis and Moringa oleifera) of the height of 195cm-360cm above the ground. The vertical distributions of studied snake on different strata of the shrubs (Ixora coccinia) at different time intervals show that, during the first 2 hours from 17:00 to 19:00 hr, the snake inhabited the top of the shrubs above cm from the ground. For the second period from 19:00 to 21:00 hr, the snakes came down slowly from higher branch to lower branch of the shrub that was about 45-90cm above the ground. From 21:00 to 23:00 hr, the snake settled longer time on lower branch was about 15-45cm above (Table 2). Most of the snake were observed at the ground level or crossing the road at third interval time. Sometimes they were encountered crossing the road at about 19:00 hr when especially the day had rain. Table 1. Seasonal occurrence on different type of vegetation of white-lipped pit viper based on observed frequency number Habitats Bamboo Tree Shrub Herb Climber season Hot Rainy Cold Total Total

5 Universities Research Journal 2011, Vol. 4, No Fig. 2 Occurrence of T. albolabris in the different types of vegetation in the campus of Yangon University Table 2. The vertical distribution of white-lipped pit viper on different strata of shrubs on timely base. Time Height strata 17:00-19:00hr 19:00-21:00hr 21:00-23:00hr cm 90-45cm 45-15cm Top Mid Low Food and feeding/hunting White-lipped pitvipers are aggressive, arboreal and active at night. When threatened or hunts the preys, a defensive strike with wide opened mouth repeats by lightly tapping the head. They ambush preys and wait motionless by hanging in an S-shaped position usually. At night they are sitting on the low layer of the bushes (about cm), the hunting position with a head directed towards the ground. The diet consists of frog was the Polypedates leucomystax, Rana limnocharis and fence lizard Calotes versicolor. In the stomach of two dead males of the snakes (one supposed it may be crushed by the car and the next one given by the man killed it), a little fresh dead body of fence lizard C. versicolor and R. limnocharis were found. Two times of the snake hunting the frogs Polypedates directly on the

6 260 Universities Research Journal 2011, Vol. 4, No. 2 ground were observed: the first time at about 19:00 hr on 22 June that had rain in the evening and the second at about hr on 2 July at the base of the bamboos. Discussion White-lipped pit vipers were observed in the campus of Yangon University situated at about 18m above sea level. As regards geographical distribution of this species, Leviton et al. (2003) stated that the elevation range is the one of the limiting factors and they concluded this species occurred only on elevation range from 60 75m in Southern Rakhine, lower part of Chin, southern Kachin, Mandalay and Sagaing Regions of Myanmar, although it is recorded at the elevation as high as 3050 m in Nepal. They are tropical snakes (Massyn, 2000) that found in northern India (Assam), Nicobar Islands, Myanmar, Thailand, Cambodia, Laos, Vietnam, southern China (Fukien, Hainan, Kwangsi, Kwantung), Hong Kong, West Malaysia, Indonesia (Sumatra, Borneo, Sulawesi, Java, Madoera, Lombok, Sumbawa, Komodo, Flores, Sumba, Roti, Timor, Kisar). In Myanmar, this snake species was found to distribute in Mandalay and Sagaing Regions as a larger number compared to the other regions of the country (Leviton et al., 2003). The study snake species showed more preference to inhabit in shrubs, climbers, herbs, bamboos and small trees respectively, but not recorded in grass land. It was suggested that the University Campus possessed many shrubs that favors this snake species to reproduce. Wogan et al. (2003) explained that this species is commonly encountered in bamboo stands, although individuals have also been found on trees, in bushes, on the ground in open fields, and crossing roads. When observed on their distribution at different strata of shrubs, they came down from top to lower layer as near as the ground at night. It was suggested that they might hunt for the frogs which are also active and moving at night. Baker (2011) explained its behaviour that this species is arboreal and nocturnal. They are active at night moving down and sitting at low layer longer in search for food such as rodents, frogs, lizards and birds. They also move on the ground at night. In the present study in nature the frogs and lizard are their foods as they were common in the campus. Baker, 2011 stated that naturally in the wild these snakes feed on frogs, birds, small rodents, lizards and geckos. In

7 Universities Research Journal 2011, Vol. 4, No captive condition, they are established feeders they have no problems for any kind of food. Conclusion The white-lipped pit vipers, T. albolabris were found in the Campus of Yangon University at elevation ranged from 18 to 26 m above sea level. They are arboreal and nocturnal. This species inhabited more in shrubs than other kinds of plants. They are mostly active in late hot season (April and May) and rainy season (June-October). The frogs and lizards were observed to be their foods sources. The present study will contribute as baseline information to the area of biology and ecology of this species. Acknowledgements We would like to express our thanks to Dr. Tin Tun Myint, Rector, for giving us permission to submit this paper and Dr. Si Si Hla Bu, Pro-Rector, Hinthada University for her valuable suggestion. We are also grateful to Professor Dr. Aung Kyaing, Head of Zoology Department, Hinthada University and Professor Daw Khin Swe Thein, Department of Zoology, Hinthada University for allowing us to conduct this study. Our thanks go to Dr. Maung Maung Gyi, Professor and Head of Zoology Department, Yangon University for his encouragement and criticisms. We are indebted to Dr. Win Maung, former Pro-Rector, Sittway University for giving some ideas on chosen topic. References Baker, N. (2011), Snakes of SE Asia: White-lipped pit viper. Online reference at ecology Asia, Cox, M.J. (1991), The Snakes of Thailand and their Husbandry. Kreiger Publishing Company, Florida. Hundley, H.G. and Chit Ko Ko (1961) List of Trees, Shrubs, Herbs and principal Climbers, Etc. Recorded from Burma with Vernacular Names. Third, Revised and Enlarged Edition. SUPDT., GOVT. PRINTING AND STATY., UNION OF BURMA, RANGOON. Leviton, A.E., G.O.U. Wogan, M.S. Koo, G.R. Zug, R.S. Lucas, and J.V. Vindum (2003) The dangerously venomous snakes of Myanmar. Illustrated checklist with keys. Proceedings of the California Academy of Sciences, 54 (24): Massyn, D., (2000), White-lipped Tree Viper (Trimeresurus albolabris) Caresheet. Online reference at snakes.com, 2011.

8 262 Universities Research Journal 2011, Vol. 4, No. 2 O'Shea, M. and Halliday, T., (2002), Handbook of Reptiles and Amphibians, published in London, New York, Munich. Siam-Info, (2011), Snakes of Thailand: Family Viperidae (Vipers), Subfamily Crotalinae (Pit viper). Online reference at ecology Asia, Smith, M.A. (1943), The Fauna of British India, Ceylon, and Burma, Including the Whole of the Indochinese Subregion, Reptilia and Amphibia. Vol. III. Sepentes, Taylor and Francis, New Deli. Wogan, G.O.U. and H. Win (2005), Trimeresaurus albolabris (White-lipped Pitviper). Resting Site. Herpetological Review 36(1): 72.