Does the size of the butterfly enhance detection? Factors influencing butterfly detection in species inventory surveys

Butterfly species’ abundance and factors influencing butterfly detection in Chimmony Wildlife Sanctuary, Kerala was studied from April to June 2018. The survey was carried out on 15 tracks of 2-km lengths surveyed two times resulting in the sampling effort of 60km. A total of 141 species of butterflies belonging to two orders, six families and 103 genera were observed during the study, of which 15 species were recorded as endemic. The majority of butterfly species belonged to the families Nymphalidae and Lycanidae. The size of butterflies varies significantly among families with the largest butterflies recorded in Papilionidae and Nymphalidae and the smallest butterflies from Hesperidae and Lycanidae. The factors that determine butterfly detection during the count was determined using multiple regression. The number of detections had a linear relation with abundance, size, and activities of the butterflies. The model was highly significant and explained 86.9% of the variation in the detection of butterflies (F=407.8; df=3; p<0.000). Abundance had a primary influence on detection followed by the size and activities of the butterflies. Further studies on relative detectability of different species of butterflies in the diversity and abundance estimation would help in refining methods of assessment of butterflies.