HABITAT PREFERENCES, DISTRIBUTION AND SEASONALITY OF THE BUTTERFLIES (LEPIDOPTERA, PAPILIONOIDEA) IN A MONTANE TROPICAL RAIN-FOREST, VIETNAM

In this paper, the butterfly community of the Tam Dao montane rain for est in northern Vietnam is described ecologically and biogeographicall y. A negative correlation between the size of species geographic range and maturity of the successional stage of its preferred habitat was f ound. This means that butterflies confined to the climax forest tend t o have a small range of distribution of endemitic type, whereas specie s associated with disturbed ruderal and similar habitats are much more widely distributed. Within the forest, understorey species are most h abitat specific and endemitic, with the most important conservation va lue. Canopy fauna is much more heterogeneous and diverse, containing a lso non-forest components. The pronounced temporal change in the fores t community is determined by the relatively higher seasonality of spec ies with biogeographical affinities to the seasonal 'East Himalayan' r egion. Apart from this historical component, the irregular migratory b ehaviour and response to the seasonal change in local environmental fa ctors seem to be important. In the ruderal habitat, butterflies with l arge geographic range tend to have the highest population sizes; the r everse is true for the forest community. Differences in current and hi storical habitat commonness and disturbance intensity are proposed to explain this pattern. The present investigations of the butterfly comm unity indicate the great importance of the Tam Dao rain forest for pre servation of the biodiversity on frontiers between the Oriental and Pa laearctic Regions.