Echolocation Mechanisms in Chiropteran Foraging Systems

Echolocating bats emit high-frequency vocalisations and analyse the returning echoes to construct a detailed acoustic image of their surroundings. This biosonar system relies on precise control of pulse timing, frequency modulation, intensity and beam shape to resolve prey, navigate cluttered environments and avoid obstacles. Across different species and foraging niches—from open-air hawkers to foliage-gleaning specialists—call parameters are tuned to habitat structure and target characteristics. In dense vegetation, rapid broadband pulses and hovering flight allow discrimination of silent or motionless prey against background echoes, whereas in open spaces highly directional, intense calls extend detection range. Flexible adjustments, such as delaying call emission to exploit quiet windows or increasing amplitude in noise (the Lombard effect), further enhance echo clarity. The interplay between anatomical adaptations (larynx, cochlea, wing morphology) and neural processing underpins the remarkable manoeuvrability and hunting success of bats, inspiring bio-inspired sonar and autonomous navigation technologies.

Research from Nature Portfolio

Recent studies have shown that some insectivorous bats dynamically shift the timing of their echolocation calls to avoid acoustic interference, spontaneously selecting temporal gaps in ambient noise to maintain signal integrity in crowded soundscapes. Investigations into the evolutionary origins of laryngeal echolocation reveal that ancestral bats possessed limited visual capacity but a sufficiently specialised auditory brain, indicating that sensory constraints drove the emergence of biosonar and that trade-offs between vision and echolocation remain evident in living species. Further work on signal plasticity demonstrates that, in noisy conditions, bats not only increase call amplitude but also extend pulse duration and group calls more redundantly, aligning signal modifications with the receiver’s sensory processing to optimise prey detection amid fluctuating backgrounds.

Research from all publishers

Engineered generative models based on variational autoencoders now replicate realistic foliage impulse responses, enabling large-scale simulation of cluttered echo environments for studying biosonar and testing biomimetic sonar devices. Behavioural experiments with a gleaning bat species have confirmed that three-dimensional hovering combined with rapid, multi-harmonic broadband calls permits the sole use of echolocation to locate silent, motionless prey on vegetation in dense understory. Complementary field studies reveal that free-flying bats produce discrete clusters of echolocation pulses—‘sonar sound groups’—with stable inter-pulse intervals when tracking unpredictable or cluttered targets, suggesting these grouped sequences enhance spatial resolution and target discrimination during aerial pursuit.

Echolocation Mechanisms in Chiropteran Foraging Systems publication trend

The graph below shows the total number of articles in echolocation mechanisms in chiropteran foraging systems across all publications each year (not limited to Nature Index journals).

Technical terms

Echolocation: Active biological sonar in which animals emit ultrasonic calls and interpret returning echoes to perceive the environment.

Lombard effect: Reflexive increase in vocalisation amplitude by a caller in response to elevated background noise.

Beam directionality: The spatial concentration of acoustic energy in an emitted sonar pulse, affecting detection range and angular resolution.

Acoustic clutter: Overlapping echoes from non-target objects, such as vegetation or terrain, which can mask prey echoes.

Sonar sound groups: Clusters of echolocation pulses with short, regular intervals used to enhance spatial detail during target tracking.

References

1. Generating Ultrasonic Foliage Echoes with Variational Autoencoders. Advanced Intelligent Systems (2024).
2. Flexible control of vocal timing in Carollia perspicillata bats enables escape from acoustic interference. Communications Biology (2023).
3. Intensity and directionality of bat echolocation signals. Frontiers in Physiology (2013).
4. Linking the sender to the receiver: vocal adjustments by bats to maintain signal detection in noise. Scientific Reports (2015).
5. BatSLAM: Simultaneous Localization and Mapping Using Biomimetic Sonar. PLOS ONE (2013).
6. Auditory opportunity and visual constraint enabled the evolution of echolocation in bats. Nature Communications (2018).
7. Timing matters: sonar call groups facilitate target localization in bats. Frontiers in Physiology (2014).
8. Perception of silent and motionless prey on vegetation by echolocation in the gleaning bat Micronycteris microtis. Proceedings of the Royal Society B (2013).