Fantastic beasts and when to find them: evaluating the effect of environmental variables on katydid activity

Ambient light can have a marked influence on the behavior of many species, particularly prey animals, where increased illumination may raise the risk of predation while offering limited advantages for activities such as foraging and mating. Katydids, which depend on species-specific acoustic signals for long-distance communication, are known to be sensitive to environmental conditions. The impact of ambient light on paleotropic katydids remains unexplored. The current study explored the effect of ambient light, temperature, and humidity on katydid assemblages at two locations, one in Northeast India, and the other in the Western Ghats, over 5 years (2015-2020). We examined possible differences across seasons and between ecosystems at each site. A total of 537 encounters through psychoacoustic monitoring were used for the analysis. The results showed that temperature and humidity had no significant impact, whereas ambient light had a significant effect on katydid activity. Katydid activity peaked closer to the waxing phase, indicating a strong influence of light. Comparison between ecosystems showed contrasting results across sites, activity peak being more closely associated with understorey in Western Ghats and to grasslands in Northeast India. Although elevated light may increase predation risk, especially in open habitats, the consequent impact on activity level of individual species varies. While previous studies explore the effect of sympatric signallers and predators, our study is the first to explore how natural environment might affect the signalling activity of katydid assemblages in palaeotropics. The repository contains data used for the analysis in Fantastic beasts and when to find them: evaluating the effect of environmental variables on katydid activity. Data was collected between 2015-2020; Hollongapar Gibbon Wildlife Sanctuary (HGWS), Assam (26°43′00″N, 94°23′00″E) and Bhagwan Mahavir Wildlife Sanctuary (BMWS), Goa (15°22′25″N, 74°15′31″E)