GEOGRAPHICAL VARIATION IN THE GENUS DENDRELAPHIS (SERPENTES, COLUBRIDAE) WITHIN THE ISLANDS OF SOUTH-EASTERN INDONESIA

The south-eastern islands of Indonesia between Bali in the west and Ti mer in the east define a region that is at the interface of the Asian and Australasian biogeographic regions. Three subspecies of the colubr id snake Dendrelaphis pictus have previously been recognized from the region: Dendrelaphis pictus pictus (Bah and Lombok); D. p. inornatus ( Sumba to Timer); and D. p. intermedius (Sumbawa to Alor). A re-examina tion of Dendrelaphis pictus in this region uses multivariate statistic s to examine the geographic variation in head-shield and body measurem ents within the species. The findings re-interpret the taxonomy, indic ating that D. pictus from Bah and Lombok are specifically different fr om D. inornatus on the remaining islands on the Banda Arc. The populat ions of D. inornatus on the islands of Sumbawa, Sumba, Sawu, Flores, a nd Lembata are subspecifically different from those on Roti, Semau, Ti mer, Alor, and Wetar. Several head-shield measures are strongly correl ated with longitude within D. inornatus, suggesting environmentally tr iggered selection gradients. However, for many variables, the two subs pecies differ significantly in the direction of the trends which sugge sts the subspecies respond differently to these environmental gradient s. There is evidence that Dendrelaphis individuals may be transported through the islands by anthropogenic agencies.