Shahriar Caesar Rahman
School of Environmental Science and Management, Independent University, Bangladesh. Bashundhara, Dhaka, 1229, Bangladesh; Lawachara Snake Research and Conservation Project, Maulavibazar, Bangladesh,
S.M.A. Rashid
Lawachara Snake Research and Conservation Project, Maulavibazar, Bangladesh,3 Centre for Advanced Research in Natural Resources & Management (CARINAM), Dhaka, 1207, Bangladesh
Kanai Das
Centre for Advanced Research in Natural Resources & Management (CARINAM), Dhaka, 1207, Bangladesh,
Chris Jenkins
The Orianne Society, 579 Highway 441 South Clayton, GA 30525, USA
Luca Luiselli
Centre of Environmental Studies Demetra, via Olona 7, 00198 Rome, Italy
Asia, Bangladesh, Monsoon, Road-kills, Seasonal activity, Serpentes
Lawachara National Park (LNP) and its adjacent areas, Maulavibazar District in the north-east of Bangladesh
Risk Management in Agriculture
Study area Field work was carried out in Lawachara National Park (LNP) and its adjacent areas. LNP is situated in Maulavibazar District in the north-east of Bangladesh and is characterized by an undulating landscape, with slopes and hillocks at an average altitude range of roughly 10-80 m a.s.l. (Nature Conservation Management, 2003). LNP is a 1250-ha mixed-evergreen forest-most of whose original forest cover has been altered or substantially removed, by rotation, with only some small, remnant patches of primary forest left inside the park (Nature Conservation Management, 2003). In between the forest habitat there are shrubs, bushes, bamboo plantations and open patches caused by human disturbance. The forest is surrounded by human modified habitats on all sides, such as tea plantations, with patches of agricultural lands, human settlements, modified vegetation for betel leaf (Piper betle), native bamboo plantations (Bambusa tulda, B. polymorpha, B. longispiculata, etc.) and monoculture forest plantations (e.g., Tectona grandis, Aquilaria crassna, Eucalyptus sp., Acacia sp., etc). Numerous streams run through the forest and the tea plantations, and there are several man-made perennial and seasonally inundated ponds in the tea plantation and the surrounding villages. For a detailed description of different habitat types see Rahman et al. (2013). LNP falls within the monsoon climatic zone, with average annual rainfall of ~3000 mm, of which 80% falls from June to September and July–August is the peak of the monsoon. October to March is dry with the first rainfall usually arriving in April. The annual mean diurnal temperature ranges from 27°C (June–September) to 16°C (January). Temperature and rainfall data were collected from Sreemongol weather station, Bangladesh Meteorological Department, located 8 km from the study site. Protocol Annual patterns of snake activity were assessed by Dead-on-Road (DOR) surveys. We assumed that there should be a linear relationship between intensity of above-ground activity in snakes and their risk of being killed along the road (Bonnet et al., 1999; Meek, 2009). However, with regard to this, it should be mentioned that this assumption may have some limitations. Indeed, DOR numbers certainly indicate the specimens which are more often found (and killed) on an open surface, i.e. on the roads, but nearly nothing can be said concerning other activities (mating, basking, etc.). DOR specimens were collected along a 7 km segment of the Sreemongol-Komgolgonj road which dissects LNP. Half of the road passes along moderately dense forest habitat and the remaining 3.5 km separates human modified habitat, with tea plantations on one side and highly degraded plantation forest in the other. The survey was conducted by walking daily (almost every day) during the survey days, from July 11, 2011 to August 31, 2012, totalling 2058 km throughout 294 road survey days. Although we realize that our study lacks spatial replicates and that sampling in at least two spatially independent locations might support the robustness of the results, we were logistically impeded to perform this type of study. Surveys were conducted from 1600–1900 hours during spring and summer months (April to August) and from 1300–1600 hours during the autumn and winter months (September to March) by one surveyor walking slowly on the road. Snakes were identified to species level following the taxonomic keys provided by Whitaker and Captain (2004) and Das (2010). The majority of the DOR specimens were identifiable to species level. However, due to their small size and similar morphology, we were not able to discriminate to species level all DOR specimens potentially belonging either to Ramphotyphlops braminus or to Typhlops spp. Therefore, for analysis, we classified them as Typhlopidae. Once inspected, all DORs were moved off the road to avoid double counts of the same individuals in different days.
Herpetological Journal Volume 23 (October 2013), 203–208
Journal