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Ba Na Nature Reserve 1996
hecabe and Catopsilia pomona, which were present (albeit in small numbers in BT3) in all the
habitats.
The family Lycaenidae, although showing greatest diversity in the forested transect BT3, were
present in greatest numbers in the the open BT1 (where over 30% of the butterflies observed
belonged to the Lycaenidae).
The Satyridae, usually associated with grasses (Spitzer et al, 1987), were abundant in all
transects. However, one species, Ragadia crisilda, appeared to be confined to the forest transect
BT3. As a larva, this species feeds on Selaginella species on the forest floor (Fukada, 1983).
The Amathusiidae (and, to a lesser extent, Riodinidae) appear to show a marked preference for
the forested transect BT3, although the numbers caught were small. These results are comparable
to those recorded at Ba Be (Kemp, Chan and Dilger, 1994) and Pu Mat, Vietnam (Kemp, Chan
and Dilger, 1995). However, the presence of one amathusiid species (Faunis cumeus) in the
early-successional BT1 suggests that there may be problems associated with the use of these
butterflies as habitat quality indicators.
7.4 Conclusions
The study at Ba Na revealed a particularly high butterfly diversity, particularly when compared to
other forest sites in Vietnam (see Kemp et al, 1994, Kemp et al, 1995). Given the seasonality of
butterfly populations, the true diversity in the reserve is likely to be even higher; many butterfly
imagos emerge in April-May in Vietnam (A. Monastryrskii, pers. comm). This diversity may be
explained by the range of habitats found within the Ba Na reserve. Although a similar number of
species was found in all the habitat types surveyed, early successional and Eucalyptus plantation
supported larger populations of butterflies. The diversity index α for the forested transect studied
was particularly high (because smaller numbers of individuals were caught here). Few species
were restricted to any one of the habitats studied, allthough many were more abundant in one or
two of the transect sites. In particular, heliophilous species and crop pests were more abundant in
the early successional and Eucalyptus transects. It seems likely that human intervention has
actually increased the number of species in the reserve area.
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