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Vol. 46 No. 2, 2007
Diurnal Retreat Site Selection by the Arboreal Chinese Green Tree Viper (Trimeresurus s. stejnegeri) as Influenced by Temperature
Hwa-Ching Lin1,2, Hsin-Yi Hung2, Kuang-Yang Lue1, and Ming-Chung Tu1,*
1Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan
2Animal Department, Taipei Zoo, Taipei 116, Taiwan
Hwa-Ching Lin, Hsin-Yi Hung, Kuang-Yang Lue, and Ming-Chung Tu (2007)
We investigated the role of vegetation cover, prey availability, and
air temperature on the selection of a retreat site by the Chinese green
tree viper (Trimeresurus s. stejnegeri),
a nocturnal, arboreal sit-and-wait predator. We manipulated the
vegetation structure and distance to the prey source, and monitored the
microhabitat temperature within the test enclosures. The results
indicated that the height of the daytime perch sites was influenced by
the ambient temperature. Snakes perched on lower layers of vegetation
seeking cooler conditions when the ambient temperature within the
enclosure was high. In addition, when the ambient temperature rose
above 25°C, tree vipers retreated into denser vegetation, which
provided significantly lower temperatures due to shading. In contrast,
tree vipers in low-temperature environments exhibited no preference for
vegetation structures in terms of density, except for an apparent
avoidance of vegetation with bare branches and no leaves. The distance
to the prey source did not appear to have any significant influence on
the green tree viper's selection of a retreat site; this could be
attributed to the fact that these snakes hunt both terrestrial targets
and arboreal species. Our study demonstrated that temperature is the
most important factor influencing retreat site selection by Chinese
tree vipers. The temporal variations and seasonal differences in the
space utilization patterns may have been attempts to satisfy their
thermoregulation needs.
Key words: Microhabitat selection, Temperature, Retreat site, Snake, Vegetation density.
*Correspondence: Tel: 886-2-29336875 ext. 321. Fax: 886-2-29312904. E-mail:biofv026@scc.ntnu.edu.tw
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