We assessed and compared the vertical stratification of butterfly flight in two forest
types within the Maragamuwa forest regeneration study site (FRSS), Matale, Sri
Lanka. Maragamuwa FRSS has two forest patches of different age categories, one is
Early Secondary Forest (ESF) and the other is Late Secondary Forest (LSF). Butterfly
flying heights recorded in both forest areas. The flight divided into three groups: Low
level (0- 1m), mid-level (1- 3m), and high level (>3m). A negative correlation (r)
between butterfly abundance and flying height was observed by performing the
Pearson correlation analysis (ESF r=-0.677, LSF r=-0.766; p<0.05). In LSF, the highest
species richness recorded at the mid-level (DMg = 9.94), which has a good
understory, while the species richness was higher in the low level (DMg = 7.61) of the
ESF, which has a good ground vegetation. The species richness was lowest at the
high level in both forest types (ESF DMg =4.18, LSF DMg = 5.71). Butterflies of the
family Papilionidae preferred to fly at high levels, and family Lycaenidae butterflies
were more abundant at low levels, which proves a positive correlation between
flying height and wingspan. Flying height increased with the wingspan (r = 0.576;
p<0.05). The main findings of this study highlight the variation of the butterfly
assemblage and flying heights with the forest succession and resource availability.
Keywords: Vertical stratification, Butterfly flight, Forest succession, Resource
availability
