Large yearly fluctuations in congregation sizes of migratory Danainae butterflies in the Western Ghats, India
Data files
May 14, 2025 version files 24.14 KB
Abstract
We documented the overwintering congregations of migratory Danainae butterflies (Nymphalidae) over six migratory seasons in the threatened tropical forests of the Western Ghats, India. Congregation sizes fluctuated drastically (>90%), indicating vulnerability to chance events. Continued monitoring is needed to explain these fluctuations and identify declining trends for timely conservation action.
Authors: P. A. Vinayan, M. A. Yathumon, Shivani Jadeja
Publication Source and Year: Biotropica, 2025
Description:
This dataset contains two data files that can be used to replicate the analysis for Vinayan et al. 2025, Large yearly fluctuations in congregation sizes of migratory Danainae butterflies in the Western Ghats, India. See Methods section of paper Vinayan et al. (2025) for details of sampling.
1. Data file name: 20250422_butterfly_congregation_size_raw_data.csv
Description:
Metadata of raw data file with data on congregation sizes (number of butterflies) collected during the study period. Variable names are described below.
*site - Unique name for each congregation site (Categorical variable)
*lat - Latitude of congregation site, low resolution (Degrees) (Quantitative variable)
*long - Longitude of congregation size, low resolution (Degrees) (Quantitative variable)
*alt - Altitude of congregation size (meters above sea level) (Quantitative variable)
*date - Date when congregation site was visited in dd-mm-yyyy format (Quantitative variable)
*count - Number of butterflies estimated at congregation site. In some cases, the number of butterflies was not estimated when there were too few individuals compared to earlier visits. In such cases count was recorded as NA. (Quantitative variable)
2. Data file name: 20250422_butterfly_congregation_size_processed_data.csv
Description:
Metadata of processed data file with data used for analysis, which includes maximum congregation sizes (number of butterflies) in a season collected across six migratory seasons. Variable names are described below.
*site - Unique name for each congregation site (Categorical variable)
*date - Date when maximum number of butterflies of the migratory season were counted at a congregation site dd-mm-yyyy format (Quantitative variable)
*count - Number of butterflies estimated at congregation site (Quantitative variable)
*season - Season of migration based on calendar year of arrival. A season was from September to May and was denoted by the year of arrival of the butterflies. (Quantitative variable)