Keywords :
Habitat Selection; Sexual Size; Dimorphism; Size Dimorphism;
Spatial Ecology; Trimeresurus
บทคัดย่อ :
Green Pit Vipers (GPV) are arboreal, crotalid snakes with more slender elongate bodies than most terrestrial pit vipers which facilitates movement through trees and bushes above the ground. The aims of this research were to investigate diversity, abundance, morphology, home range, behavior of GPVs in Sakaerat Environmental Research Station (SERS) from May 2012 to February 2015. Three species of GPVs Trimeresurus macrops, T. albolabris and T. vogeli were captured in SERS. Total of 35 snakes (27 females and 4 males of T. macrops, 1 female of T. albolabris and 2 females and 1 male of T. vogeli), inhabiting mixed deciduous and dry evergreen forest, were implanted with internal radio transmitters and tracked from 11 to 208 days. Individual Minimum Convex Polygon home ranges for T. macrops averaged 0.0201 ha, with activity areas of 0.038 ha (95% Fixed kernel) and core areas 0.0199 ha of (50% Fixed kernel). Adult morphological characters of 139 T. macrops, 3 T. vogeli and 3 T. albolabris obtained by active searches and opportunistic captures from May 2012 to October 2014 were compared. Additionally, 7 external characters including residual index and scaled mass index (SMI) between male and female T. macrops were significantly different. Male head size in T. macrops was negatively correlated with SMI, which may reveal intersexual competition in T. macrops. Sexually dimorphic characters in T. macrops may have evolved through intraspecific resource partitioning. We assessed relative abundance of the three GPV species at SERS using a variety of sampling methods. A total of 285 GPV captures were recorded during the study period, with 203 individuals (190 T. macrops, 9 T. albolabris and 4 T. vogeli). Trimeresurus macrops and T. albolabris did not show site specific tendencies in relative abundance; however, T. vogeli was found exclusively in deep evergreen forest. We used randomly selected microhabitat quadrats to test ambush site selection of T. macrops. This snake selected sites with deeper leaf litter, larger stems, and greater numbers of shelter sites surrounding the site than random points in the forest. Four novel behavioral observations were recorded for GPV during the study period, which have expanded the knowledge base of the natural history of T. macrops and T. vogeli. Our research has demonstrated the need for careful consideration when attempting to assess relative abundance among secretive arboreal snakes, and highlights the knowledge gap in this little studied snake group.
เอกสารอ้างอิง :
Strine, C. (2014). The ecological study of green pit vipers in Sakaerat environment research station, Nakhon Ratchasima (Doctoral dissertation, School of Biology Institute of Science Suranaree University of Technology).
