Predicting acoustic orientation in complex real-world environments

Abstract

Experiments were carried out in the natural habitat of Plebeiogryllus guttiventris (Walker), which consists of hard ground sparsely covered with herbs and forbs. In the area being videotaped, vegetation cover was almost completely removed in order to allow us to view the females clearly. We believe that the environment created by this manipulation is not unnatural since several of the natural habitats where we have observed these crickets consist of SUMMARY Animals have to accomplish several tasks in their lifetime, such as finding food and mates and avoiding predators. Animals that locate these using sound need to detect, recognize and localize appropriate acoustic objects in their environment, typically in noisy, non-ideal conditions. Quantitative models attempting to explain or predict animal behaviour should be able to accurately simulate behaviour in such complex, real-world conditions. Female crickets locate potential mates in choruses of simultaneously calling males. In the present study, we have tested field cricket acoustic orientation behaviour in complex acoustic conditions in the field and also successfully predicted female orientation and paths under these conditions using a simulation model based on auditory physiology. Such simulation models can provide powerful tools to predict and dissect patterns of behaviour in complex, natural environments.

Insect acoustic communication: The role of transmission channel and the sensory system and brain of receivers

“…Given these distorted directional cues, how can the phonotactic behaviour of insects cope with these conditions? Only three studies have quantified phonotactic tracks of acoustic insects towards a sound source in no‐choice or choice trials outdoors, two for field crickets (Hirtenlehner & Römer, ; Mhatre & Balakrishnan, ) and one for a parasitoid fly approaching the target in flight (Tron & Lakes‐Harlan, ). The significant findings were as follows: in no‐choice trials, all female crickets approached the target, but the distance covered was significantly larger compared to similar laboratory trials.…”

“…intensity differences are greater than 12 dB in favour of the less attractive signal), the trade‐off would result in a choice of the less attractive signal. Rather than the result of complex cognitive mechanisms, such decisions may probably also be explained by physiological properties of sound processing in the auditory pathway (Mhatre & Balakrishnan, ). These authors tested field cricket acoustic orientation in complex acoustic conditions in the field and successfully predicted female orientation using a simulation model based on auditory physiology.…”

Insect Hearing

“…The acoustic context can be highly variable in the wild depending on signaler densities, source SPLs, signal structure, habitat, and movement, and it is necessary to validate results obtained under laboratory conditions by testing them in realistic fi eld scenarios. In one such attempt, Mhatre and Balakrishnan ( 2006 ) characterized the acoustic context experienced by female crickets ( Plebeiogryllus guttiventris ) in the fi eld and incorporated it in a simulation wherein the auditory localization mechanism was modeled to produce "virtual female crickets" that performed phonotaxis when presented with multiple, simultaneously played out calling songs representing males in a dense chorus (Mhatre and Balakrishnan 2008 ). The same "chorus" (using speakers) was experimentally set up in the fi eld where phonotaxis trials were carried out with real females (Mhatre and Balakrishnan 2008 ).…”

Grasshopper calling songs convey information about condition and health of males

“…Such correlations between morphology and song parameters allow the females to discriminate between males with diVerent morphological features. Often bigger males are preferred and this preference may lead to an increased reproductive success (GreenWeld 1997;Couldridge and van Staaden 2006;Mhatre and Balakrishnan 2008;Ponce-Wainer and Cueva del Castillo 2008). Bigger males exhibit advantages in other physiological properties, too.…”