Vol. 47 No. 6, 2008

Food Habits of the Taiwanese Mountain Pitviper, Trimeresurus gracilis

Chia-Fan Lin and Ming-Chung Tu*

Department of Life Science, National Taiwan Normal University, 88 Ting-Chou Road, Sec. 4, Taipei 116, Taiwan

Chia-Fan Lin and Ming-Chung Tu (2008) We studied the food habits of the Taiwanese mountain pit viper, Trimeresurus gracilis, by checking gut contents and conducting feeding trials.  In total, the stomach contents of 160 snakes were checked.  The stomachs of only 27 (16.9%) snakes contained prey items, and most (88.5%) of the prey items had been swallowed head-first.  The prey-predator mass ratios ranged 0.08-0.81, and prey mass was positively correlated with snake snout-vent length.  An ontogenetic diet shift from ectothermic to endothermic prey was evident: only ectotherms (lizards, 91.7% and amphibians, 8.3%) were found in the guts of yearlings, whereas mammals (rodents and shrews) represented 68.1% of gut contents of adults.  Additionally, adult females and males presented different diets.  Females preyed mostly on rodents (45.5%), whereas males preyed mostly on shrews (59.3%).  Consistent with the gut content analysis, in feeding trials, neonates preferred lizards and frogs whereas adults preferred mice.  Invertebrate prey was always ignored in the feeding trials and was considered to be secondary prey.

Key words: Snake, Diet, Gut content, Food, Ontogenetic diet shift.

*Correspondence: Tel: 886-2-29336234 ext. 321.  Fax: 886-2-29312904.   E-mail:biofv026@ntnu.edu.tw