Activity time budget of Pieris canidia at an elevational gradient in Himachal Pradesh, India
Student name: Mr Sushant D. Potdar
Guide: Dr Sudipta Chatterjee
Year of completion: 2016
Host Organisation: National Centre for Biological Sciences (NCBS), Bengaluru
Supervisor (Host Organisation): Dr Krushnamegh Kunte
Abstract: Butterfly behaviour is greatly dependent on the environmental variables of that ecosystem. Since
butterflies are poikilothermic, they need to bask in the sun to acquire the body temperature
needed for flight activities like feeding, mate location and oviposition. Butterflies exhibit both
physiological and behavioural mechanisms to acquire the required body temperature. Basking is
the most important behaviour by which they acquire body temperature. Since this is dependent
on temperature, it is seen that butterflies bask for longer time at higher elevations. This gives
them less time for other flight activities thus having implications on their population and
community dynamics. Pieris canidia is a montane butterfly found abundantly in Himalayas with
an elevational distribution from 300 m to 3200 m making them ideal for studying the influence of
environmental variables on their behaviour at an elevational gradient. The study was conducted
at 12 locations covering all the elevations across the state of Himachal Pradesh, India during
February to April, 2016. The scan sampling was done for 384 individuals. Flight was the major
activity at all elevations. But the percentage of individuals flying at higher elevations was less
than at low elevations. Basking was seen predominantly by individuals at higher elevations. In
focal animal sampling, a total of 507 individuals were sampled. Time allocated for basking
increased with increase in elevation. Time allocated for flight was low at 300-800 m elevation
but peaked at 800-1300 m. It decreased with elevation subsequently. Time allocated for other
activities which depend on flight were greater at lower elevations than at higher elevations. It
was found that elevation and temperature were the main factors for causing the variance in the
data. It is important to study the changes in behaviour temporally due to changing climate.
Increase in temperatures at low elevations can cause thermal stress in butterflies making them
allocate most of their time perching in cooler places while it can give more flight time for
individuals at higher elevations.
Key words: thermoregulation, behaviour, activity time budget, flight temperature, Pieris canidia
