Sexual signalling is a fascinating aspect of animal communication, involving stereotypical behaviors that secure mating opportunities. In many species, individuals employ multiple alternative reproductive tactics (ARTs) to achieve reproductive success. These tactics may be fixed or flexible—the latter being context-dependent—and can be influenced by physical, ecological, physiological, or social factors. In species with socially flexible ARTs, individuals adjust their behavior based on the surrounding social environment. As sexual signals traverse the environment to reach potential mates, they are simultaneously detected by competitors and sneakers.
In my thesis, I examine the social dependence of ARTs using Oecanthus henryi as a model. O. henryi, is a tree cricket native to Peninsular India and Sri Lanka, typically found on the host plant Hyptis suaveolens. Males produce a calling song by rubbing their wings, and the females exhibit phonotaxis towards singing males. Males employ four distinct alternative reproductive tactics: (i) calling, where a male sings while perched on a leaf lamina or edge; (ii) baffling, in which a male constructs a baffle on the leaf surface—shaped like his wings—to amplify his call by reducing destructive interference; (iii) silent strategy, where the male does not sing; and (iv) satellite strategy, characterized by a silent male moving towards a caller or baffler.
In the first chapter, I explore how the presence of conspecific acoustic signals influences the adoption of ARTs through playback experiments that vary the number and intensity of these signals. In the second chapter, I investigate how physical interactions with conspecific males affect tactic expression by manipulating competitor presence. In the third chapter, I assess the impact of the adopted ART on male reproductive success via controlled mating experiments. Overall, my work explores how competition shapes alternative reproductive tactics and the influence of alternative tactic adopted on reproductive outcomes.