Eco-ethology study of butterfly species found in set up garden in an urban area, Kolkata, India
Debapriya Chakraborty Thakur and Anuradha Chaudhuri
The objective of the present study was to identify the habitat preferences (ecology), nectar-plant as well as host-plant interaction and different behavioural (ethology) activities in the unmanaged and set up garden within the campus (southern side) of Lady Brabourne College, Kolkata, India. The set up garden was constructed in an effort to offset the damage caused to their habitat due to heavy construction activity/anthropogenic disturbances in the campus. The study was conducted of an area of about 30m X 14m size through focal-animal sampling method and studied in two phases as in the first phase,survey of butterflies’ habitat and behavioural activities within anunmanaged garden in the campus prior to construction activity (May 2012 to October, 2012) and in the second phase, setting up a garden in another site of same campus with plantation of host plants preferred by butterfly species between October, 2012 to June, 2015. Specific behaviour pattern like resting, hovering, basking, flight, courtship flight, chasing, mud puddling, mating and also nectaring preferences of local butterflies for local plants was studied. The results showed that Plains Cupid spent maximum time on basking (21%), other species 10 % to 13% or less time. The Blue Tiger, Castor, and Common Jezebel showed nectaring (8-10%) and others species 3-7%. Resting (10-15%) was seen by Common Grass Yellow and other species viz. Plains Cupid, Forget-Me-Not, Peacock Pansy, Gram Blue and Common Mormon were not found in resting. Blue Tiger, Mottled Emigrant, Lime Butterfly, Common Jezebel, Psyche spent maximum time (9-15%) on hovering. No hovering activity was observed in Plains Cupid, Forget-Me-Not, Common Evening Brown. On courtship, Plains Cupid shows maximum activity. Common Evening Brown spent most time sitting in cool shady place sitting on garbage, ripped fruit etc. Mottled Emigrant (19.5%), Blue Tiger (18%), Common Castor (11%), Striped Albatross (6%) were observed to mudpuddle. This study indicates preference of weeds as nectar source by the different families of butterflies. In conclusion, this study emphasizes the importance of saving some land in a garden for the so-called weeds. The normal ethology indicates their adaptation in the new habitat and success of effort for restoration of sustainable ecosystem in the urban area.