Vol. 37 No. 4, 1998

Sexual Size Dimorphism and Microhabitat Use of Two Sympatric Lizards, Sphenomorphus taiwanensis and Takydromus hsuehshanensis, from the Central Highlands of Taiwan

Wen-San Huang

Department of Zoology, National Museum of Natural Science, Taichung, Taiwan 404

Wen-San Huang (1998) Sexual size dimorphism and microhabitat use of 2 syntopic lizards, Sphenomorphus taiwanensis and Takydromus hsuehshanensis, from the central highlands of Taiwan are examined. Adult S. taiwanensis females attain a larger body size than do males, but in T. hsuehshanensis, body size shows no significant difference between sexes. Head sizes of males are larger than those of females in both species. All morphological traits of T. hsuehshanensis are larger than those of S. taiwanensis. The 2 species differ considerably in microhabitat use horizontally. T. hsuehshanensis was collected predominantly in cultivated land of Brassica oleracea capitata, while S. taiwanensis was found mainly in a saxicolous area. Neither T. hsuehshanensis nor S. taiwanensis shows significant differences in microhabitat utilization between sexes. Morphological differences were observed between the 2 species, and these are presumably associated with their differential microhabitat preferences. The longer forehand of T. hsuehshanensis allows a greater degree of locomotor activity. Causality of snout-vent length dimorphism of 5 sympatric lizards are also discussed.

Key words: Syntopic, Lizards, Sexual size difference, Squamata, Taiwan.

*Correspondence: Tel: 886-4-3226940 ext. 510. Fax: 886-4-3232146. E-mail: wshuang@nmns1.nmns.edu.tw