Seasonal dynamics and polyphenism of butterfly communities in the coastal plains of central Western Ghats, India

Abstract

Long-term socioeconomic progress requires a healthy environment/ecosystem, but anthropogenic activities cause environmental degradation and biodiversity loss. Constant ecological monitoring is therefore necessary to assess the state of biodiversity and ecological health. However, baseline data is lacking even for ecologically sensitive regions such as the Western Ghats. We looked at the seasonality and polyphenism of butterflies of the central Western Ghats to get baseline population patterns on these charismatic taxa. We recorded 43118 individuals (175 species) using fortnightly time-constrained counts for two consecutive years, and found the peak abundance (49% of the total individuals) in post-monsoon period (Oct to Jan). The seasonal abundance was correlated with the overall increase in species richness.Habitat differences were stronger than seasonality as samples clustered based on sites. Several species also displayed polyphenism with distinct distributions of wet and dry season forms.Seasonal equitability and indicator species analysis showed distinct inter-species differences in seasonality patterns. This work provides key baseline data on the seasonal dynamics of butterflies of the Western Ghats in the context of climate change and conservation, and will help in future monitoring of this ecologically sensitive region using butterflies.

Diversity, Seasonal Dynamics and Host Plants of Butterflies in Forest Research Centre, Siddipet, Telangana, India

“…3, which considers the mean number of species occurrences from five different families, it is evident that the highest mean number of species occurrences was observed during the rainy and winter seasons, with a noticeable decline during the summer season. These results differ from the observations made by [38,39] but are in line with the findings reported in these studies [37,[40][41][42]. During the hierarchical cluster analysis of the Bray-Curtis similarity index using Past 4.03 software, the study uncovered interesting patterns.…”

A comparison between time‐constrained counts and line transects as methods to estimate butterfly diversity and monitor populations in tropical habitats

“…We decided on the duration of 30 min for timed counts based on: (a) the sizes of habitat patches (all of which were large enough to conduct many 30-min counts per day); (b) number of sampling replicates that we could do per day (6-12 counts) based on the amount of time spent in the field, seasonal climatic parameters, and butterfly activity, and also repetitions as a total effort over the entire duration of the study; and (c) our knowledge of the general diversity and encounter rates of butterflies based on our long-term field experience in these habitat patches. In our experience, the duration of 30 mins works well for sampling butterflies and odonates in many habitats and habitat patches in India, and this count duration has been used for the past 15 years of sampling (Kunte et al, 2012;Naik et al, 2022aNaik et al, , 2022bSondhi & Kunte, 2016). The 30-min counts are also used now as a standard method for data collection under the Indian Butterfly Monitoring Scheme (iBMS, https://ibms-network.in), and are integrated into its mobile data app and Microsoft Excel template for data collection (https://ibms-network.in/resources-formonitoring).…”

“…Time-constrained counts (henceforth, 'timed counts') is an alternative visual-count method for conducting butterfly surveys and population monitoring (Beneš et al, 2003;Kadlec et al, 2012;Kral-O'Brien et al, 2021;Naik et al, 2022aNaik et al, , 2022bSantorufo et al, 2021;Taron & Ries, 2015). In timed counts, effort is standardised by time rather than by length/area as done in line or belt transects.…”