Impacts of big birding events in tropical Asia – a case study from Kerala

Big birding events provide a valuable opportunity to develop datasets to supplement systematic bird monitoring. However, the contributions of these big datasets remain unclear. In this study, we examine two big birding events in Kerala, India (Great Backyard Bird Count and Onam Bird Count). Data submitted during these events between 2014 and 2022 were analysed to assess data quantity, species representation, spatial coverage and birder recruitment. The events contributed a disproportionately large amount of data (12% of all Kerala bird data) and effectively recruited volunteers (> 50% recruited in 2 months) into the citizen science programme. Although the data exhibited a spatial bias (missing 18% of Kerala), the reporting frequencies of common birds from these events were in agreement with the semi-structured birding efforts conducted throughout the rest of the year. The simplicity of their protocols and reasonably high data quality make big birding events a useful component of citizen science. Promoting such events is useful for engaging citizens in bird monitoring and conservation, especially in densely populated and biodiverse countries such as India.