Thesis Progress at CES on 4 August 2021 at 3:00 pm titled "Predation risk of different mate-finding strategies in katydids" by Kasturi Saha from Indian Institute of Science, Bangalore
Predation is a strong selection force that can potentially change the mate-finding strategies of prey. However, what makes one prey more risk-prone to predation relative to another depends on various ecological and behavioural factors and their interactions. Predation risk can be different for different species, different sexes of the same species and even for different behaviours of the same sex. One of the questions we try to address is why we see sex-biased predation by bats on katydids (bushcrickets) and to understand that we investigated the risks associated with different sex-specific behaviours. From the wing remains of katydids collected from the roosts of a bat predator Megaderma spasma, we see interesting patterns of predation for two different katydid species. For the genus Mecopoda, more male wing remains are found in the breeding season, and more female wings are found in the non-breeding season, whereas for another katydid Onomarchus uninotatus, more female wings are found throughout the year. Interestingly, these two katydids have different strategies for mate-finding. In Mecopoda, only the males signal and the silent females move towards the singing males, whereas O. uninotatus performs a multimodal duet, where both males and females can signal and search. We conducted behavioural experiments and observed bat responses to free-moving males and females of these two katydids, while they engaged in signalling using acoustic or vibratory cues and searching by walk or flight. Flight emerged as the highest risk factor for males and females of both katydid species, whereas walking was not found to be risky.