The seasonality of butterflies in a semi-evergreen forest: Gibbon Wildlife Sanctuary, Assam, northeastern India

Abstract

A study spanning 3.7 years on the butterflies of Gibbon Wildlife Sanctuary GWS (21km2), a semi-evergreen forest, in Jorhat District of Assam, northeastern India revealed 211 species of butterflies belonging to 115 genera including 19 papilionids and seven ‘rare’ and ‘very rare’ species as per Evans list of the Indian sub-continent (Great Blue Mime Papilio paradoxa telearchus; Brown Forest BobScobura woolletti; Snowy Angle Darpa pteria dealbatahas; Constable Dichorragia nesimachus; Grey Baron Euthalia anosia anosia; Sylhet Oakblue Arhopala silhetensis; Branded Yamfly Yasoda tripunctata). The butterflies showed a strong seasonality pattern in this forest with only one significant peak during the post monsoon (September-October) when 118 species were in flight inside the forest which slowly declined to 92 species in November-December. Another peak (102 species) was visible after winter from March to April. Species composition showed least similarity between pre-monsoon (March-May) and post-monsoon (October-November) seasons. The number of papilionid species were greater from July to December as compared from January to June. The findings of this study suggest that the pattern of seasonality in a semi-evergreen forest in northeastern India is distinct from that of the sub-tropical lowland forest in the Himalaya. Favourable logistics and rich diversity in GWS points to its rich potential in promoting ‘butterfly inclusive ecotourism’ in this remnant forest.

Keywords

• Conservation
• eco-tourism
• endemic
• Papilionidae
• rainfall
• rare
• semi-evergreen forest.