Publications

Published work, preprints, methods, and developing research across active sensing, behavioural bioacoustics, and theoretical ethology.

Highlighted work

June 2025 Preprint Research

The Temporal Logic of Bat Echolocation: A Responsivity Theory of Call Timing Patterns

Umadi, Ravi and Firzlaff, Uwe

The temporal patterning of bat echolocation has been extensively characterised and used to interpret behavioural regulation during active foraging. Yet a general mathematical account linking these patterns to acoustic propagation, relative motion, and the timing of behaviourally selected information remains incomplete. Here we present the responsivity fra...

Paper
May 2026 Ecology and Evolution Research

Temporal Feasibility Constraints on Wingbeat-Call Synchrony in Actively Echolocating Bats.

Umadi, Ravi

Echolocating bats operate within a closed sensorimotor loop in which call emission, echo reception, sensory processing, and motor response are linked by finite propagation delays and bounded response times. Although synchrony between wingbeats and call timing is frequently observed, it remains unclear when such coordination is temporally feasible and when...

Paper
January 2026 Methods in Ecology and Evolution Methods

ESPERDYNE - A Dual-Band Heterodyne Monitor and Ultrasound Recorder for Bioacoustic Field Surveys.

Umadi, Ravi

1. Background. Ultrasonic monitoring is essential for ecological studies of bats and other animals, yet high-performance field devices remain prohibitively expensive and inaccessible-particularly in biodiversity-rich regions with limited research infrastructure. Existing low-cost options often lack real-time listening and require a complex setup. There re...

Paper
August, 2025 BMC Ecology and Evolution Research

Widefield Acoustics Heuristic - Advancing Microphone Array Design for Accurate Spatial Tracking of Echolocating Bats

Umadi, Ravi

Accurate three-dimensional localisation of ultrasonic bat calls is essential for advancing behavioural and ecological research. I present a comprehensive, open-source simulation framework—Array WAH —for designing, evaluating, and optimising microphone arrays tailored to bioacoustic tracking. The tool incorporates biologically realistic signal generation, ...

Paper
March 2026 Preprint Methods

RUBAT Studio - A Unified Workbench for Multichannel Bioacoustic Data Acquisition

Umadi, Ravi

1. High-resolution ultrasonic recording is central to modern bioacoustics, behavioural ecology, and passive acoustic monitoring. Yet, implementing flexible, multichannel acquisition systems with real-time playback, monitoring and experimental control remains technically demanding. Existing solutions often require bespoke code development or expensive prop...

Paper
February 2026 Preprint Research

WAH-i - Optimising Microphone Array Geometry for Customised Localisation Accuracy

Umadi, Ravi

1. Accurate spatial localisation of free-flying echolocating bats is foundational for resolving fine-scale flight behaviour, prey interception, and spatial decision-making in natural environments. Acoustic localisation using microphone arrays is widely employed for this purpose, yet array geometries in field studies are typically chosen heuristically rath...

Paper
January 2026 Preprint Research

Rates, Ripples, and Responsivity - The Geometry of Echolocation in Water-Foraging Bats

Umadi, Ravi

Water-surface foraging is a rare strategy among echolocating bats, requiring precise coordination between sonar emission, echo timing, and flight geometry. Here, I develop a geometric-responsivity framework to explain how bats foraging over water regulate call timing under these constraints. The model links beam projection, flight height, and specular sur...

Paper
August 2025 Preprint Methods

BATSY4-PRO - An Open-Source Multichannel Ultrasound Recorder for Field Bioacoustics

Umadi, Ravi

Background: Behavioural studies of echolocation and acoustic communication in free-flying bats depend on multichannel ultrasonic recordings. However, access to these methods remains geographically uneven: tropical and subtropical regions harbour much of the world's bat diversity yet remain underrepresented in experimental behavioural bioacoustics. Convent...

Paper
2025 TUM School of Life Sciences. Accepted and Awarded Doctoral dissertation

Echolocation Dynamics in Active Foraging and Pursuit

Umadi, Ravi

Echolocating bats rely on self-generated biosonar signals to perceive and navigate their environments. While traditional models treat echolocation as a rigid, reflexive behaviour with fixed emitter and receiver geometries, empirical evidence suggests a high degree of plasticity in both signal generation and spatial sampling. This thesis explores the dynam...

2025 Under Review Research

Probabilistic Sensory Constraints Shape Swarm Cohesion in Echolocating Bats

Umadi, Ravi

1. Cohesive animal groups rely on continuous behavioural updating to regulate spacing, alignment, and collision avoidance, yet all sensory-guided interaction is constrained by finite signal propagation delays, processing time, and motor latency. In actively sensing species such as echolocating bats, these constraints raise a fundamental ecological questio...

Paper
2025 Under Review Research

Oscillating Ears Dynamically Transform Echoes in Constant-Frequency Bats

Umadi, Ravi

Constant-frequency (CF) bats exhibit rapid oscillations of their external ears. Yet, the functional role of these movements has remained unresolved since their initial documentation over half a century ago. Although recent studies have demonstrated that pinna motion generates Doppler shifts, they do not explain why ear oscillations intensify at close rang...

Paper
2019 Heritage Research

The Monumental Mistake of Evicting Bats from Archaeological Sites—A Reflection from New Delhi

Umadi, Ravi and Dookia, Sumit and Rydell, Jens

We highlight the importance of an integrated management policy for archaeological monuments and the insect-eating bats that roost inside them. We refer to India, but the issue is general and of worldwide significance. There is increasing evidence that the ecosystem services provided by insect-eating bats in agricultural fields are of vital economic import...

Paper