Animal communication and bioacoustics lab
Rohini Balakrishnan
Member, Executive Council,
International Bioacoustics Society
My research interests
Animal communication and Bioacoustics
A major aim of my research is to understand the causes and consequences of animal behaviour in natural environments at both proximate and ultimate levels, for which I use acoustic communication as the model. The methods employed are both reductionist (using behaviour and physiology) and synthetic (using simulations), with concurrent quantification of the natural abiotic and biotic environment, the latter providing the ecological context and thus the selection pressures under which animals must survive and reproduce.
RESEARCH THEMES
Acoustic communication in noise
We examine sender and receiver strategies for communication in complex, noisy natural acoustic environments. Over the last couple of decades, my research group has worked on an assemblage of acoustically communicating species of crickets and katydids in and around the tropical evergreen forests of Kudremukh National Park in South-Western India. Signal structures, transmission and signaller behaviour have been examined for evidence of sender strategies to avoid masking interference. Receiver strategies are being examined in terms of auditory mechanics, physiology and behaviour. A detailed understanding of senders, signals and receivers provides insights both into the functioning of natural communication networks and the evolutionary forces that do or do not drive them. Potential evolutionary drivers include the transmission medium (examined using habitat acoustics), acoustic competition (via masking interference), phylogenetic constraints and predation.
The sensory and behavioural ecology of mate-finding and mate choice
We aim to understand mating strategies in crickets and katydids in terms of both their physiological mechanisms and their ecological and evolutionary context. We examine mate-finding strategies in field and tree crickets using acoustic signals, as well as in the acoustic-vibratory duetting, canopy katydid species Onomarchus uninotatus. Current projects also examine the drivers and fitness consequences of alternative mating strategies (calling, baffling and satellite) in tree crickets.
Predator-prey interactions
We are interested in how spatio-temporal patterns of availability of insect prey, together with their movement and signalling behaviour, influence foraging strategies and outcomes for predators, resulting in sex- and species-biased predation. On-going studies focus on the foraging ecology and foraging strategies of the lesser false vampire bat, Megaderma spasma. We also attempt to quantify sex- and species-specific predation risk for insect prey in the wild, as well as examine the effects of predation on prey signalling and mating strategies. Current study systems include bats, katydids and moths, as well as spiders and tree crickets.
Acoustic monitoring of biodiversity
We are interested in developing and validating methods for rapid, reliable acoustic biodiversity monitoring across a range of taxa. We use three approaches: 1) developing libraries of the calls of different insect and vertebrate taxa, currently including crickets, katydids, birds and bats; 2) developing and calibrating psychophysical sampling methods for taxa that signal in the audio range and 3) developing and/or validating AI-based ecoacoustic methods.
