Abstract:
Sri Lanka is one of the most biologically diverse countries in the world. Two
hundred and forty four (244) species of butterflies have been recorded in Sri Lanka
of which twenty one (21) are endemic. Nectar plants are one of the major
determinant factors of life cycle, population abundance and distribution of
butterflies. The present study investigated the seasonal abundance and diversity of
butterflies in selected trails in Kiralakelle natural reserve, aiming promotional
activity for an ecotourism site in Matara District. Four butterfly trails were selected
during the initial survey and point scan line-transect technique was used to survey
of butterflies. Abundance, Diversity and Evenness indices were estimated.
Seasonal abundance of recorded butterflies was counted twice a month from
January to December 2008. Active time period, occurrence and distribution of
different vegetation strata and abundance of nectar plant of recorded butterflies
were also studied during the survey. The recorded 24 butterflies represented 9
families and 24 species. Common Rose was the only recorded endemic butterfly.
Banded Blue Pierrot and Small Banded Swift were recorded two rare species,
Great Crow was uncommon, and threatened one was Banded Blue Pierrot. The
highest number of butterfly species recorded in Family: Danaidae, Nymphalidae,
PapiIionidae. Five butterfly species were abundant throughout the year. Seven
butterfly species were found during the specific period from April to
September/October. Species diversity was highest in trail 2, whereas species
percentage was high in trail 1. Evenness was highest in trail 2 as it shown highest
degree of spread of individuals between species. Traill had the highest abundance
of butterflies with representing drastically high population of Blue Glassy Tiger.
Great Crow represented only trail 1 and Angled castor confined to trail 2. Most
suitable time period to watch butterflies is between 9.00 a.m. - 3.00 p. m. during
the day and highest number of butterflies observed in ground level stratum( <lm).
There was a significantly positive correlation (r2 = 0.816, P<0.05) between
recorded overall abundance of butterflies and nectar plants in each trail. A check
list of recorded butterfly species was prepared. In the light of overall result, trail I
and 2 give high opportunity for tourists to enjoy by watching butterflies in
Kiralakelle nature reserve. Additional conservation actions immediately require for
trail 3 and 4, to minimize disturbance by human, buffaloes and solid waste.
Furthermore, Butterfly populations could be enhanced by promoting the abundance
of recorded food plants and forest shade in these disturbed habitats.
