Echo-Imaging Exploits an Environmental High-Pass Filter to Access Spatial Information with a Non-Spatial Sensor.

Echo-imaging evolved as the main remote sense under lightless conditions. It is most precise in the third dimension (depth) rather than in the visually dominating dimensions of azimuth and elevation. We asked how the auditory system accesses spatial information in the dimensions of azimuth and elevation with a sensory apparatus that is fundamentally different from vision.

Insectivorous bats integrate social information about species identity, conspecific activity and prey abundance to estimate cost-benefit ratio of interactions.

Animals can use inadvertent social information to improve fitness-relevant decisions, for instance about where to forage or with whom to interact. Since bats emit high-amplitude species-specific echolocation calls when flying, they provide a constant flow of inadvertent social information to others who can decode that acoustic information. Of particular interest is the rate of feeding buzzes-characteristic call sequences preceding any prey capture-which correlates with insect abundance.

Does similarity in call structure or foraging ecology explain interspecific information transfer in wild bats?

Abstract: Animals can gain important information by attending to the signals and cues of other animals in their environment, with acoustic information playing a major role in many taxa. Echolocation call sequences of bats contain information about the identity and behaviour of the sender which is perceptible to close-by receivers. Increasing evidence supports the communicative function of echolocation within species, yet data about its role for interspecific information transfer is scarce.

Linking the sender to the receiver: vocal adjustments by bats to maintain signal detection in noise.

Short-term adjustments of signal characteristics allow animals to maintain reliable communication in noise. Noise-dependent vocal plasticity often involves simultaneous changes in multiple parameters. Here, we quantified for the first time the relative contributions of signal amplitude, duration, and redundancy for improving signal detectability in noise.

Personal messages reduce vandalism and theft of unattended scientific equipment.

Scientific equipment, such as animal traps and autonomous data collection systems, is regularly left in the field unattended, making it an easy target for vandalism or theft. We tested the effectiveness of three label types, which differed in their information content and tone of the message, that is, , or , for reducing incidents of vandalism and theft of unattended scientific field equipment. The three label types were attached to 20 scientific equipment dummies each, which were placed semi-hidden and evenly distributed in four public parks in Munich, Germany.

Interspecific acoustic recognition in two European bat communities.

Echolocating bats emit echolocation calls for spatial orientation and foraging. These calls are often species-specific and are emitted at high intensity and repetition rate. Therefore, these calls could potentially function in intra- and/or inter-specific bat communication.

Bats' avoidance of real and virtual objects: implications for the sonar coding of object size.

Fast movement in complex environments requires the controlled evasion of obstacles. Sonar-based obstacle evasion involves analysing the acoustic features of object-echoes (e.g.

Sonar detection of jittering real targets in a free-flying bat.

The auditory system measures time with exceptional precision. Echolocating bats evaluate the time delay between call and echo to measure object range. An extreme and disputed result on ranging acuity was found in the virtual delay jitter experiments.

Cues for acoustic detection of prey: insect rustling sounds and the influence of walking substrate.

When insects walk, they generally produce sounds. These can reveal the walkers' presence and location to potential predators such as owls, bats and nocturnal primates. Additionally, predators might extract information on taxon, palatability, size or profitability from the rustling sounds.

Comparing passive and active hearing: spectral analysis of transient sounds in bats.

In vision, colour constancy allows the evaluation of the colour of objects independent of the spectral composition of a light source. In the auditory system, comparable mechanisms have been described that allows the evaluation of the spectral shape of sounds independent of the spectral composition of ambient background sounds. For echolocating bats, the evaluation of spectral shape is vitally important both for the analysis of external sounds and the analysis of the echoes of self-generated sonar emissions.