Research Inga Geipel

Abstract

For the detection of their prey, echolocating bats produce ultrasonic calls and listen for echoes reflected off the insects. Gleaning bats hunt by taking resting prey from the vegetation. They hunt in an acoustically highly challenging and complex environment, such as the forest understory. As active flight is energetically very costly and the great majority of understory leaves do not hold resting prey, bats must have developed behavioural and acoustical strategies to efficiently check a vast amount of vegetation surfaces for the presence of prey. Here, I investigate which underlying foraging strategy echolocating bats use to efficiently search for resting prey in the forest understory. State-of-the art stereo high-speed video recordings synchronised with multi-microphone array recordings will be used to observe bats in a behavioural experiment searching for prey randomly placed on leaves of an artificial vegetation. To analyse the bats' 3D flight-paths and the corresponding echolocation behaviour I will train neural networks to perform automated pose tracking of the bats' foraging behaviour. The combination of detailed, three-dimensional behavioural and acoustic analysis will lead to a better understanding of the underlying mechanisms of efficient prey detection and foraging behaviour of bats in structurally and acoustically complex environments. Furthermore, the project will also offer the opportunity to inform and inspire biomimetic methods and applications for efficient acoustic object detection.

Researcher(s)

• Promoter: Geipel Inga

Research team(s)

• Co-Design of Cyber-Physical Systems (Cosys-Lab)

Project type(s)

• Research Project

Abstract

In the arms race between prey and predators, diverse anti-predator defence mechanisms evolved. To avoid predation, many insects developed camouflage (crypsis) or chemicals that render them distasteful or toxic. To warn of their unpalatability, many insects evolved striking warning colours or patterns (aposematism). Insects comprise most of the diet of bats. Some of these nocturnal predators glean resting, silent, motionless diurnal insects from the vegetation. Instead of using vision during foraging, they produce ultrasonic calls and detect their prey through echolocation. Here, I want to research whether visually cryptic or aposematic insects also have cryptic or aposematic acoustic reflection properties, to hide from or signal their unpalatability to echolocating bats. I will use bio-inspired sensor systems to acquire echo-acoustic sonar recordings of selected insect species and conduct behavioural prey-detection and -capture experiments using live bats to explore the prevailing acoustic predator-prey interactions. Based on these experiments, I will apply neural network algorithms for classifying and analysing the distinguishing features in different insect echoes. This approach will allow an in-depth investigation of the underlying acoustic mechanisms of the interaction between prey and predators and will inform and inspire biomimetic applications for detecting and identifying objects by sonar. Further, the project will lead to synergism between the research fields of biology and engineering in the study of animal interactions and bio-inspired robotics.

Researcher(s)

• Promoter: Steckel Jan
• Co-promoter: Peremans Herbert
• Fellow: Geipel Inga

Research team(s)

• Co-Design of Cyber-Physical Systems (Cosys-Lab)

Project type(s)

• Research Project

Abstract

In this project we investigate acoustic aposematic signalling in insects. We combine acoustic measurements with computational bat behaviour modelling to gain insights into the effects of aposematic signalling on the bat's perception mechanisms.

Researcher(s)

• Promoter: Steckel Jan
• Fellow: Geipel Inga

Research team(s)

• Co-Design of Cyber-Physical Systems (Cosys-Lab)

Project type(s)

• Research Project