Projects of the group "Acoustic and Functional Ecology"
Sensory processes are at the centre of our perception of the world and our behavioural actions in this world, including some of the most crucial behaviours for survival such as foraging and predator avoidance. Accordingly, natural selection has not only shaped the morphology of animals, but also their sensory and behavioural properties. The overall objective of our research is to understand the function and adaptation of sensory systems in relation to an animal's biotic and abiotic environment, and how sensory information guides appropriate behaviour.
Auditory object analysis is the basis for the biosonar-based perception of the world of echolocating bats. To understand the ecology of echolocation, we need to understand how object features are coded in echoes, how these echoes are analysed by the auditory system, and how these perceptual strategies are adapted to an species’ ecology.
Besides habitat perception, prey detection is one of the most important and challenging tasks for echolocation. In many groups of prey, ears evolved and set the stage for a coevolutionary arms race between echolocating predators and prey with bat-detecting ears. We focus on echolocating bats and eared moths, which interact with each another in a functional, ecological and evolutionary relationship. This predator-prey-relationship is solely based on acoustic information and auditory-guided behaviour for foraging and for predator avoidance, respectively. Investigating dynamic sensory processing in bats, we ask which sensory mechanisms in emission and perception enable bats to successfully capture erratically moving prey? In turn, we ask which behavioural strategies of moths make for an effective escape from attacking bats.
Echolocation calls cannot only be heard by prey: bat calls are some of the loudest biotic sounds and transmit information about the species, ecological niche and current behaviour of the calling bat. Echolocation calls are thus a potential source of information for other bats in the vicinity, which bats might exploit for their own decision making.
The transmission of any sound signal, be it used for communication or prey detection, is influenced by abiotic factors such as ambient noise and atmospheric conditions. This influence is of growing concern due to anthropogenic disturbances such as noise pollution and global warming. Using experimental and modelling approaches, we investigate how anthropogenic effects affect sensory perception, and if bats can compensate for them.
When pursuing insects, bat echolocation has to be highly dynamic since both prey and predator constantly change relative positions during flight. Additionally, eared moths perform erratic evasive manoeuvres when under attack, thereby adding a fast, unpredictable component that significantly decreases the capture success of bats. Foraging bats therefore have to constantly adapt call emission and perception in a highly dynamic way.
The auditory analysis of the echoes reflected off objects in the bats' surrounding is the basis for a biosonar-based perception of the world. To understand the ecology of echolocation, we need to understand how object features are coded in echoes, how these echoes are analysed by the auditory system, and how a bat's perceptual strategies are adapted to its ecology.
Animals are under the constant pressure to make adaptive decisions, for example during foraging, for finding shelter or mates, and predator avoidance. Information provided by other animals, both con- and heterospecific, can help in this decision making process.
Many adaptations evolved in prey animals in response to predation threat, such as mimicry to trick the visual system, spines to mechanically prevent predation, or behavioural adaptations. A common anti-predator behaviour is unpredictable movement, so called protean behaviour.
We are living in a fast changing world - so do animals. Some of the most pronounced changes globally include increasing human population and rising atmospheric CO2 concentration, leading to increasing air temperature, background noise and light pollution.